When Pass labs introduced the dual chassis Xs monoblocks a couple of years ago, they raised the bar for other components, and in the process even raised the bar for their own, already excellent XP30. We could end the review here by saying that on one level the difference between the XP30 and the XsPre is very much like the difference between the XA.8 series power amplifiers and the Xs monoblocks; everything is bigger, bolder, cleaner and quieter than what has come before.

Taking the financial aspect out of the equation, with the XsPre tipping the scale at $38,000 and the XP30 less than half of that at $16,500, the XsPre offers a lot more, if you have the room, system and software able to resolve the difference. For those that are familiar, think of the XP30 as a standard Porsche 911 and the XsPre as a fully geeked out GT3. You don’t need it to get the job done, but if it won’t affect your meal plan to acquire, you won’t be disappointed.

It’s no secret our publisher is incredibly enthusiastic about Pass amplifiers.  While the company’s flagship Xs300 monoblocks have been serving dual duty as his reference amplifiers and the furnace for the TONEAudio studio for some time now, his relationship with Nelson Pass is more than a mere bromance. It goes all the way back to the early 1980s, when we lived on Milwaukee’s East Side and he talked me into helping him carry his new Threshold 4000A power amplifier up a few flights of stairs.

I’m a tube guy; I’ve always been a tube guy – the tubey-er, the better. Back in 1980-something, that Threshold was a mind-bender because this massive solid-state amplifier made the room warmer than any tube amplifier I had ever experienced, sounded as musical as anything with glowing bottles, yet had killer bass output and control. It even sported an awesome set of red LED power output meters! The 4000A stayed in my system for a long time after our publisher’s terrier-like nose for all things audiophile led him sniffing down other paths and, as with one of my prized BMW 2002s, I still regret selling it.

It’s all about control

Don’t let Nelson Pass’s easy demeanor fool you; he wants control. At least control of your speakers’ cones. The major benefit to the massive power supplies and output stages in the two-chassis Xs amplifiers is the amount of control they enforce on your loudspeakers. Not letting the drivers act in a willy-nilly manner keeps distortion and non-linearity at bay, resulting in a cleaner, clearer, less fatiguing sound. Pass is fond of saying that he likes the sound of tubes without the hassle, and the Xs300s deliver this in abundance. But at almost $90K per pair they are not within the reach of every audio enthusiast.

Enter the XA160.8 monoblocks at $29,000/pair. Building on the success of the .5 series (you can read our review of the XA160.5 monoblocks here[1] and the XA200.5 monoblocks here[2] ) the .8 series of Pass amplifiers takes these designs a major step further. Larger power supplies and a more refined circuit allow these new amplifiers to be biased further into class-A territory. The changes draw more power from your wall, and generate more heat – something we put to good use here in the Pacific Northwest. The results put the 160.8 closer in sound to the massive, two-chassis Xs amplifiers than before. The price tag is still not pocket change, but a far cry from what the four-chassis, big boys will set you back.

Pass makes it a point to let you know that these are not cookie-cutter amplifiers, with each version sharing an input stage followed by progressively larger output stages. Every model in the .8 series is individually designed from the ground up with all nine amplifiers in the range using different input and driver circuitry optimized for progressively larger output stages. A peek inside the case reveals a prodigious bank of power supply capacitors flanked by equally huge heat sinks, each with “more output transistors than necessary.”

With balanced XLR inputs (the XA160.8 is a fully balanced design) and RCA inputs, this amplifier works well with any preamplifier. My ARC REF 5 proves a perfect match for the XA160.8, but after spending a bit of time with the top-of-the-line Xs Pre, I’m guessing it’s upgrade time again.  Even my standby CJ PV-12 turns in an amazing performance with these amplifiers and reminds me of when I used the Threshold 4000A with a CJ PV-2a preamplifier. Time does fly when you’re having fun. Watch for our review of that piece very soon. Suffice it to say that the XA160.8 will never be the weak link in your hifi system!

Taking care of business

Vicariously sampling the last four or five Pass amplifiers that have been in for review, it’s time to put the latest models front and center in my reference system and flog them. Rage Against the Machine’s “Take the Power Back” does the trick, as the intro kick drum beats and bass riffs occupy separate spots in the soundstage, neither losing their focus as I turn the volume up, up, up – pushing my head back against the couch. Yet near the end of the track as the pace settles to light cymbal work, the delicacy and texture rendered stops me dead. It’s so quiet and precise, everything appears to settle into nothing.

Sporting the big, blue circular meters that adorn the face of all the Pass power amplifiers, the 125 pound (each) XA160.8s are a breeze to move after the Xs300s. However, they’re probably a stretch for one person lifting, so you should consider getting some help to keep your back in order. For those not familiar with Pass amplifiers, the meter needle stays centered, indicating that the amplifier is operating fully in class-A mode, which for the 160.8, is 328 peak watts. So when that needle starts to bounce, these amplifiers are indeed producing major power.

Driving my Vandersteen 5As with the XA160.8s is absolutely peachy and the synergy with the Audio Research REF5SE is near perfection as well. I have spent some time with the Pass Xs Pre that is here for review, and that’s even more revealing. It goes without saying that you won’t go wrong with an all-Pass system, and as Mr. Pass says, you’ll never have to look for tubes again.

Break-in has been the same experience we’ve had with all other Pass amplifiers; they sound great straight out of the box and improve linearly over about 300 hours, with a minimal increase in clarity after that. Though solid state, they take as long as, if not longer than, a vacuum tube amplifier to fully “warm up.” Due to the power draw (550 watts per monoblock) and heat generated, most owners will not want to leave them on all the time. The XA160.8s take about 90 minutes to come out of the gentle mist exhibited at initial power up that dissipates after they reach full operating temperature. You’ll notice it in the smoothness of the upper register and the depth of the soundfield portrayed – getting deeper and deeper, drawing you further in to the presentation as they stabilize.

The 160.8s are consistent at low, medium and high volume. They never run out of steam when cranking AC/DC to near-concert levels, yet when listening to solo vocals or piano at levels barely above a whisper, maintain depth and a tonal richness that you’d expect from a flea watt SET amplifier. To say these amplifiers are incredibly linear and dynamic is an understatement.

In the end

We’re all worm food. But for now, if you find yourself asking the venerable question, “tubes or transistors,” this tube guy says buy the XA160.8 from Pass Labs. Unless you can afford the Xs monos, then of course you know what you must do.

Additional Listening: Jeff Dorgay

Selfishly, it’s always wonderful when someone else shares my enthusiasm for a piece of audio gear, and in this case, it’s been an ongoing argument between myself and Mr. O’Brien for a couple of decades now. While I agree with his analysis, because of the nature of the Vandersteen 5As only needing to be powered from about 80hz up, (because of their internally powered woofers) these speakers don’t give the full scale of the XA160.8s’ performance. And, of course, we like to perform amplifier reviews with as wide of a range of speaker systems as possible to see if there are any rocks in the road. I assure you there are none.

As with all the other Pass amplifiers we’ve auditioned, the XA160.8 continues the tradition of being able to drive any load effortlessly. I began my listening with the toughest speakers in my collection, the Magnepan 1.7s and the Acoustat 2+2s. Both passed with flying colors, and it was an interesting comparison to play the 2+2s with both the XA160.8s and a recently restored Threshold 400A that I used to use with my 2+2s in the ’80s. The more powerful, heavier, 4000A only stayed in my system briefly, but the 400A stayed for quite some time and was always a favorite.

Thanks to so much current on tap, the 2+2s now sound like there is a subwoofer in the room, but more importantly, these speakers, known for their somewhat loose and flabby lower registers are exhibiting taut, tuneful bass in a way they never have. Thomas Dolby’s “Pulp Culture” shakes the listening room with authority. An even tougher test is acoustic bass, and again the vintage ESL’s dance through all of my favorite Stanley Clarke tunes.

Moving through the gaggle of great speakers we currently have here from Dali, Dynaudio, GamuT, Eggleston and a few others, the XA160.8s have no limitations. To get them to (softly) clip requires ear shattering volume, or perhaps a pair of horribly inefficient speakers. In that case, there are always the XA200.8s and the Xs amplifiers.

No matter what music is served, the XA160.8s perform effortlessly and get out of the way for your enjoyment of it. The biggest delight, aside from knowing you’ll never have to hunt down matched quartets of power tubes again, is just how much of the flagship Xs300s capability is locked up inside these two boxes at one third of the price. Mind you in a “cost no object” system, the difference between the XS160.8 and the Xs300 will still be easily apparent, but it’s like the difference between an $85,000 Carrera and a $175,000 GT3RS – it’s easy to see, feel and hear the lineage,  and for those who don’t want to go all the way, will still find the lower-priced sibling still highly enjoyable.

I’ve hinted that the Pass XA160.8s have the slightest bit of warmth in their overall character, which they do. However, this additional richness and palpability is not at the expense of softness, or compromise in transient attack. If you want a strictly “nothing but the facts” the Pass sound may not be for you, but if you’ve always loved a touch of the glow that the world’s best vacuum tube amplifiers possess without having to chase the glass bottles, you must audition the XA160.8 I guarantee you will be highly impressed.

The Pass XA160.8

$29,000/pair

www.passlabs.com

PERIPHERALS

Analog Source	SME 20/SME V arm     Koetsu Urushi Blue
Digital Source	Simaudio MOON 650D    MacBook Pro
Amplification	ARC REF 5     Pass Xs Pre
Speakers	Vandersteen 5A
Cable	Cardas Clear

The Digital Amplifier Company—founded in 1996 and located in Allentown, Penn.—solely produces hyper-engineered, audiophile-grade Class-D amplifiers. Its products output plenty of power from manageably sized and attractive packages. The company’s Cherry line comprises stereo and monoblock variants, which are available in standard or higher-output Ultra configurations.

The company says it does not use prefabricated modules and that it designs all vital components in-house, with everything built in the Unites States. Every amplifier comes built to user specifications, allowing customers to choose standard or Ultra configurations and the amp’s color. The company sells direct to end users.

The $4,000-per-pair Cherry Maraschino monoblock model is the newest brainchild of company designer Tommy O’Brien. The Maraschinos are mighty mites, with published output power of 250 watts into 4 ohms. The parts employed are very high quality and include Dayton binding posts, Neutrik XLR inputs, and high-tolerance metal oxide resistors.

The amps feature true balanced input and external power supplies with IEC receptacles. These power supplies are upgradeable, with an available power increase of up to 800 watts. The chassis sits on a granite block, with Sorbothane feet for resonance control. The Maraschinos are produced with a brilliant, high-quality red finish (which is fitting considering the amp’s name).

Setting up the Maraschinos is pretty straightforward, with some twists. The accompanying documentation asks that the user plug in the power supplies last, after all other connections are made, and with low-level music playing through the system. There is no power switch, as the amps automatically detect a signal and come out of standby mode; when no signal is present for a period of time, they return to standby. The amplifier sensitivity is on the high side, at 2.2 volts, but that should be no issue with most preamps and sources.

The Maraschinos accept only XLR inputs, but very nice RCA-to-XLR adaptors are supplied. The adaptors are put to good use, as a passive preamp is what we put ahead of the amps, driving a pair of Harbeth Compact 7 ES3s. Sources include a variety of DACs and disc players. Cabling comes courtesy of Transparent, Shunyata, and Stager Sound.

The amplifiers very much make their identity known from the get-go, with their wonderfully open, clear, transparent, and precise sound. There are no mechanical artifacts or spotlighting of any kind. There is a top-to-bottom, even keeled balance that becomes very quickly addicting such that even familiar recordings come alive with a fresh perspective. This may be due to the Maraschinos’ incredibly quiet background. Music seems to appear out of the ether. Recordings that seemed previously homogenized now appear spacious and wide.

The amps render the Punch Brothers’ Antifogmatic with startling dynamics, precise imaging, and stop-on-a-dime timing. Chris Thile’s well-recorded vocals and virtuoso mandolin playing take on very human qualities, and the groups clever arrangement of Radiohead’s “Kid A” through the Marachinos is worth the price of admission alone.

Peter Gabriel’s New Blood, featuring new interpretations of some of his classic songs, is a hair-raising showpiece through the Maraschinos. The recording is amazingly dynamic; the use of a live orchestra in lieu of rock instrumentation allows the amps to showcase their sound-staging chops. One listen to the new version of “San Jacinto” brings you as close to the recording as you could hope for.

The recent 96 kHz remaster of Nick Drake’s three sublime albums are ravishing through the Maraschinos. Having heard these albums in every format and through countless amplifiers, I find it rather impressive that they still sound fresh, with the amps unexpectedly lifting even more detail from the recordings. If you have a collection of high-resolution music, the Maraschinos will serve you well, as they reproduce what the mastering engineers intended.

After cycling through more genres of music, I discover that the Maraschinos greatest strength is coherence. Bass notes are deep and punchy yet speedy and nimble, with high frequencies sounding extended and smooth. Certainly, system matching is going to be important here. If your speakers edge toward the speedy side of things, that may be too much of a good thing with the Maraschinos. These amps will expose lean-sounding speakers and sources. If listening preferences trend toward mellow and rosy, there will be other amps to look at. However, if clarity, brilliance, and agility are your thing, then the Maraschinos will serve you well. A balanced tube preamplifier ahead of the Maraschinos may indeed provide a perfect balance of both worlds. Neutral, open-sounding cables will also pay dividends.

Perhaps the only quirk to nitpick is that one of the amps is slightly less sensitive than the other, so it takes a few extra seconds to come out of standby. This is not a deal breaker; just a minor annoyance. The fact that the amps save watts while still being ready for optimum performance when awakened is worth the trade-off. They also run cool as a cucumber—a very nice contrast to some of the space heaters usually in for review.

The Digital Amplifier Company has wonderful success on its hands with the Cherry Maraschino monoblocks. By the way, the company’s name does not reflect its design mission: It does not make digital amplifiers. These are analog amps all the way. They are amazingly refined with low distortion. Those accustomed to bogus mid-bass warmth may think the Maraschinos are a bit vivid, but in reality they provide a clean window and they have speed to spare.

If your system needs a kick in the pants, the Maraschinos will deliver. They make our reference system come alive. It is like cleaning a dirty windshield to get a better view of the road. At $4,000 per pair, the Maraschinos are not entry-level amps. They deliver all the real-world power you need, and they’re upgradeable, efficient, great looking, and terrific sounding. These amps give listeners a good look at what the very best amps do well, for a fraction of the cost. Pair them with high-quality sources and speakers and they will deliver the sonic goods.

Cherry Maraschino Monoblocks

MSRP: $4,000 per pair

Digital Amplifier Company

www.digitalamp.com

PERIHPERALS

Speakers	Harbeth Compact 7 ES3
Preamp	Channel Islands Audio PLC-1  MKII
CD transport	Musical Fidelity M1 CDT
DAC	Denon DA-USB300    CLONES Audio Sheva
Music server	Squeezebox Touch
Cables	Transparent    Shunyata    Stager    DH Labs

Power output meters are just cool. Back in the late 80s when the legendary Audio Research D-79 amplifier stood as my system’s cornerstone, watching the meters bounce into the red “caution” area—as the SPL got somewhat out of hand—made me feel like a mad scientist in a Mothra movie, waiting for sparks to fly. Fortunately, they never did, and my D-79 never missed a beat.

Today, my hair is as gray as the front panel on my ARC REF 150 power amplifier, which has served me equally well. But with a pair of speakers possessing an 88dB sensitivity rating, there are times when I find myself itching for a bit more power. And as awesome as a pair of REF 750s sound, the idea of replacing 36 KT120 power tubes on a semi-regular basis scares me. Perhaps if I could buy them by the palette at Costco…

For every one that’s lusted after a Ferrari and bought a Porsche 911 because it just made more sense on a daily basis, I submit the ARC REF 250 monoblocks. At $26,500 per pair, they are not an impulse purchase. Yet for those with an ARC amplifier (or amplifiers) already in their system, trading up isn’t a stretch. ARC’s Dave Gordon likes to say that the company’s best entry-level product “is a good, clean piece of used ARC gear.” Sounds like it’s time to pass that pair of REF 110s or VT100 on to another happy owner, and roll up to the bar for a pair of REF 250s. Then again, I can justify anything related to audio.

Quite the Trip

I have one main requirement for five-figure hi-fi: It has to take you on a trip, giving you an immersive experience that allows you to forget about the system and groove on the music. Forget about specs, measurements, tube, or transistor. Once the REF 250s have about 45 minutes on the clock, they take you there.

What better place to start than with the Beatles’ Magical Mystery Tour in stereo? Argue mono versus stereo all day long, but the latter version is extremely trippy, and as wide as a stretch of US 40, driving through Kansas on a clear, sunny day. Lennon is all the way out in Missouri, McCartney is over in Colorado, Ringo drums g somewhere in Nebraska, and George Harrison sits in the seat right next to you. Who needs drugs when music sounds this good? The mix tightens up on Revolver, with more dynamics. Harrison’s guitar blazes out in front of the speakers, buzzing in my head during the chorus on “Taxman.”

Next up, AC/DC. Taking advantage of an all-ARC amplification chain, this time using the REF Phono 2, AVID Acutus Reference SP, and Lyra Atlas cartridge (mounted on the TriPlanar arm), the 45RPM single of “Let’s Get it Up” (from For Those About to Rock) sends the power meters dancing at the edge of the caution zone. It’s like old times, but better. Much, much, better. Move over Rover, the new REF series is where it’s at. Not stopping there, I dial up the 24/96 release of Kiss’ Destroyer from HD Tracks. Aural madness ensues.

The sheer dynamic punch the REF 250s possess is simply unbelievable—the soundstage never collapses, even at near concert-hall levels. I haven’t listened to music this loud in my listening room in a long time. Yet the REF 250s handle it so effortlessly, it’s easy to keep goosing the volume control further and further, waiting for a hint of compression or distortion. It never arrives. With all due respect to the ARC dealer network, unless a bunch of listeners have fearfully inefficient loudspeakers, I don’t know why they’d need the REF 750s.

Moving the cables back to the REF 150, the amplifiers sound relatively similar, especially at modest levels. Still, the full mono chassis and bigger power supplies make for a wider, deeper soundstage and more solid foundation to the bass lines, no matter what kind of music pours out of the speakers. Yes, the REF 250s are double the cost, but offer a commensurate increase in performance.

Catch the Buzz

A quick beverage break reveals I’m listening way too loud. My ears now have a slight tingle, so the volume comes down from 81 on the REF 5SE to a more prudent 30. Coasting through Aimee Mann’s new Charmer album provides an audio sorbet that calms and cleanses the palette before I peruse recent Music Matters Blue Note reissues. The REF 250s’ extra power and separate power supplies expand Blue Note’s super stereo feel beyond the norm, excelling in texture retrieval.

Forget The Sheffield Drum Record. Art Blakey’s Free For All is an amazing example of the maximum amount of drum sound a vinyl groove can hold. The REF 250s take the music beyond conceivable limits. I continue to push the volume, but my system never runs out of juice. This is the closest I’ve come to actually hearing a real drum kit in my room. Cymbal tone and texture are spot on, but Blakey’s explosive drumming doesn’t flatten out for lack of amplifier reserve.

Even with a fairly compressed track like U2s “Beautiful Day,” soundstage depth impresses. The Edge’s backing vocals, often lost in the mix, occupy their own private space, well off to the left speaker boundary, yet unmistakable nonetheless. Given how well they reproduce average recordings, the REF 250s seem borderline miraculous.

Slowing the groove for Mickey Hart’s audiophile classic Dafos makes for a welcome reunion. The delicate percussion in “The Subterranean Caves of Kronos” gets rendered with sublime smoothness, putting me at rest for almost three minutes until the monstrous drums of “The Gates of Dafos” sledgehammer my body into the listening chair and place me in the middle of a tribal mating ritual. Once again, the REF 250s strike an ideal balance between control, finesse, and impact. Herein lies the magic: massive power, yet the REF gear starts and stops on a dime, allowing for an incredibly fatigue-free experience.

Easy Implementation

The REF 250s prove at ease with every speaker we have at our disposal: GamuT S9, Sonus Faber Ellipsa SE, B&W 802D (notoriously difficult to drive), and even the Magnepan 1.7.  Thanks to multiple taps at 16, 8, and 4 ohms, you should be able to find the winning combination for your speakers.

Setup is also a snap, and at 73 pounds each, the REF 250s are not too dificult to move. As with any tube amplifier, they require adequate ventilation. The REF 250s are fan-cooled and extremely silent in operation. They use the same 20-amp IEC connector as other ARC gear, so keep this in mind if you are thinking of upgrading power cords. ARC claims power usage as 700 watts at 250-watt output, and 1000 watts “maximum.”  While you can use both on a 15-amp circuit, listeners pumping up the volume at high levels will benefit from a 20-amp dedicated circuit for the amplifiers.

Configuration

Along with doubling the power supply from the REF 210 it replaces, the REF 250 utilizes a design very similar to the REF 150, with eight KT120 power tubes per channel (instead of four) being driven by another pair of KT120s and the 6H30 that seems to be universal in current ARC amplifiers. A 6550C is employed as a voltage regulator. In a nod to past ARC designs, a traditional analog meter replaces the fluorescent display.

The KT120 tube proves excellent across the range. In addition to the increased power dissipation (which translates into increased power output), the KT120-based ARC amplifiers have more aural ease than earlier amplifiers using the 6550. Depth and air are more abundant, with speakers disappearing in the room more convincingly. And nobody’s going to complain about that.

Audio Research REF 250 Monoblocks

MSRP: $26,500/pair

www.audioresearch.com

Peripherals

Analog Source	AVID Acutus Reference SP    TriPlanar    Lyra Atlas
Digital Source	dCS Paganini stack    Sooloos Control 15    Aurender S10
Preamplifier	ARC REF 5SE
Phonostage	ARC REF Phono 2SE
Speakers	GamuT S9    Magico S5    Sonus faber Ellipsa SE    B&W 802D
Power	RSA Maxim and Dmitri
Cable	Cardas Clear
Accessories	Furutech DeMag and DeStat    Audio Desk System RCM    GIK acoustic panels and Tri Traps

Revisiting Dave Grusin’s classic audiophile album, Discovered Again!, brings back frustrating memories of how amplifiers in the early ’80s didn’t have enough horsepower to do justice to a record with wide dynamic swings.  The same dilemma exists when playing many of today’s carefully remastered records with ultra-wide dynamic ranges:  Even though there is no obvious distortion, something is still missing.  And you don’t know it until you hear what a mega power amplifier can achieve.

Forget “simpler is better,” “lower power is better” or whatever other mantra you’ve let yourself be convinced by to avoid making the step up to a high-quality, high-power amplifier.  You’re in for a shock the first time you plug the MOON 880Ms into your system.  It’s a “space, the final frontier” kind of thing, with the 880Ms opening up a parallel universe where the Enterprise now goes to warp 13, instead of only warp 9.7.

At $42,000 per pair, these amplifiers are not for the faint of wallet—but the only other amplifiers I’ve heard with this kind of jump factor are the $205k-per-pair Boulder 3050s.  Instead of spending that kind of cash, you could go with a pair of the 880Ms, Simaudio’s $28,000 MOON 850P preamplifier, your favorite $25k digital front end, a similarly priced analog front end, and maybe $40k for a great pair of speakers. You’ll still have enough cash left over for European delivery of a new Porsche Cayman S and a trip to the Montreux Jazz Festival for a week to take in some great live music.  To the right buyer, the MOON 880Ms are a major bargain—it’s all relative.

The Un-Compressor

Thom Yorke’s The Eraser is a fairly compressed recording, as is Supreme Beings of Leisure’s album 11i. The recently remastered Deluxe Version of Thin Lizzy’s Jailbreak feels tighter still. The MOON 880Ms bring these dense albums to life in a way the other amplifiers at my disposal simply cannot do.  It’s like driving a high-revving, high-horsepower V-12 supercar that produces its power without the help of a turbo or supercharger—there’s an immediacy to the throttle response that a boosted car never has, even though it may have more torque.

When it comes to amplification, reserve power is essential if you love metal or large-scale orchestral music.  Distortion is the enemy of tweeters, and playing metal at high volumes will easily liquefy your speakers if your amplifier can’t deliver massive amounts of ultra-clean power.  I don’t think I’ve ever played System of a Down’s single “B.Y.O.B.” as loud as I did with the MOON 880Ms, and it never became painful.  These amplifiers are without practical limit, even with my 89-dB speakers.  If you have a more sensitive speaker up in the range of 93 to 95 dB @1 watt, like the Focal Grande Utopia EMs, Wilson XLFs or Verity Lohengrins, I’d highly suggest a good calibrated level meter to protect your ears from damage.  The extra dynamic range of the MOON 880Ms produces a listening experience so free of artifacts that you’ll likely catch yourself playing music a lot louder than you normally do.  And dammit, that’s really cool.

Even at modest levels, the MOON 880Ms sound clearer and more spacious.  On Liszt’s Hungarian Rhapsodies for Orchestra, 1-6, from the recent Mercury CD set, the initial attack on the string bass at the beginning of the first piece, combined with the glorious hall ambience, only begins to prepare you for the excitement in store as the full orchestra kicks in about three minutes later.  And the tone?  Fantastic.  Oboes and violins just float silky and softly through the listening space, and are never the least bit grainy.  These amplifiers simply do not impose a sonic signature on the music, and they always get out of the way of the presentation.  The MOON 880M does run in Class-A mode for the first 10 watts, and the transition to Class-AB at higher levels and power peaks is achieved seamlessly.

The Amplifier or the Egg?

Visiting the Simaudio factory last summer, I had the privilege of listening to the MOON 880Ms for the first time, driving a pair of Dynaudio Confidence C1 II speakers in Simaudio’s listening room, which is about 20 feet by 30 feet and expertly tuned to take the room out of the equation.  Upon returning home, my own pair of C1s was somewhat disappointing in comparison.  As one who loves a good rationalization, I chalked it up to the better room tuning and went about my business.

After properly treating my listening room, that experience was still missing by a substantial margin.  The MOON 880Ms in my room convince me that it’s the amplification making the big difference.  Though it may come across as controversial to some, especially those who think that speakers are nearly everything, I propose that the amplifier affects the system’s overall sound just as much as the speakers do, if not more.  Pairing the MOON 880Ms with some excellent but modestly priced speakers (like the splendid KEF LS50s or the Harbeth Compact 7ES-3s) makes for a bigger, more spacious and detailed sound than connecting a $50k pair of speakers to the best $1,000 integrated amplifier you can find.

Playing Thievery Corporation’s The Richest Man in Babylon is a revelation through these amplifiers, even though I’m sure you’ll be buying a better pair of speakers for the 880Ms in your house.  Yet, these great compact speakers, which sound spectacular paired with a Rega Brio-R or a PrimaLuna ProLogue integrated, offer a breathtaking experience with the MOON 880Ms.  They now have real bass weight where there was barely any before.  Like any of the large floorstanding speakers used for this review, these amplifiers’ enormous power reserves redefine control.  This kind of current is not swayed by the reverse EMF generated by the loudspeakers to anywhere near the extent that it is with a small amplifier.

Moving back to my reference GamuT S9s, tracking through DJ Cheb i Sabbah’s La Ghriba: La Kahena Remixed is a religious experience for those worshipping at the temple of mega bass.  The throbbing, tribal beats in this record compress my spinal column as the volume approaches club level without a trace of strain, and as the final notes fade to extreme black, it’s tough to find where my room boundaries lie, even with my eyes open.  You don’t need to dim the lights to get into a deep, deep, listening experience with these amplifiers.

Of course, the better recordings at your disposal will benefit even further.  Aphex Twin’s 26 Mixes for Cash features a broad sonic landscape in all directions, deriving much of it from all the low-frequency bass texture—an area that the MOON 880Ms enhance considerably.  Tracking through a large stack of audiophile workhorses, the gestalt of the MOON 880Ms is crystal clear:  These amplifiers provide incredible resolution; yet, even after 12-hour listening sessions, they are never fatiguing.

Right Brain, Left Brain

The MOON 880Ms feature top-quality casework, with aluminum enclosures produced in Simaudio’s Montreal facility on its own five-axis CNC mill and anodized to last a lifetime, perhaps longer.  (Those wanting a more in-depth view of the company’s operation can click here for our recent visit: <<<INSERT LINK>>>.)  Simaudio’s engineers feel that the effort spent on solid casework not only eliminates vibration from the electronic environment, but also makes for stunning aesthetics—again an emphasis on quality and value.

As an added bonus, all this power comes in a relatively compact package.  These monoblocks will fit on any rack capable of supporting about 100 pounds each.  Simaudio’s high-biased, Class-AB design runs barely warm to the touch, even at high volume levels, and the company uses standard 15-amp IEC sockets.  As with the other giant monoblocks reviewed in this issue, the 880Ms will work on a single 15-amp circuit, but will perform even better with a dedicated 20-amp circuit, preferably a pair of dedicated 20-amp circuits.

Lifting the cover reveals a fully balanced design that also has an RCA input for those not having a fully balanced preamplifier.  Each amplifier utilizes 32 matched Motorola output devices, along with a pair of 1.3-kV power transformers and 240,000 uF of power-supply capacitance—all contributing to the complete lack of noise in the 800M’s presentation.  This is an amplifier that music lovers and technology geeks can both cuddle up to; all the right boxes are ticked.  Those wanting a further technological analysis, click HERE.

Call Me Crazy

But don’t call me Shirley.  Though a pair of the Simaudio MOON 880M amplifiers costs as much as a 3-series BMW, consider this:  These amplifiers will easily last 20 to 30 years without any attention.  If you leased a new 3 series every three years for the next 20 years, you’d have spent just over $100,000 and still not have a fixed asset at the end of the term.  Considering that over 90 percent of all the Simaudio components ever made are still playing music without effort (and have a 10-year warranty), that pair of 880Ms you buy today will probably still be worth $5,000 to $10,000.

Jay Leno once said that car enthusiasts are either check writers or wrench turners, which also applies to many audiophiles.  Taking it a step further, one faction of audiophile is on a quest to swap gear nearly constantly in search of an elusive grail, while another diligently assembles an excellent system and pursues music exploration with fervor.  While we won’t pass judgment on either camp here, if you fall into the latter, a pair of MOON 880Ms can be your final destination—even if you swap speakers a few times on your journey, there’s nothing they will not drive.

Factoring that into the equation, the Simaudio MOON 880Ms represent an exceptional value, and are highly deserving of one of our Exceptional Value Awards for 2013.  They provide a sonic experience that few amplifiers can match, at any price, and they are built to the highest levels of quality.

Simaudio MOON 880M Mono Reference Power Amplifiers

MSRP: $42,000 per pair

www.simaudio.com

Peripherals

Analog Source	VID Acutus Reference SP turntable     TriPlanar arm    Lyra Atlas cartridge    AMG V-12 turntable    AMG arm    Clearaudio Goldfinger cartridge
Phonostage	Simaudio MOON 810LP    Indigo Qualia
Digital Source	dCS Vivaldi stack    Sooloos C-15    Aurender S10   Simaudio MinD
Preamplifier	Simaudio MOON 850P    Audio Research REF 5SE    Robert Koda K-10
Speakers	Dynaudio Confidence C1 II    Sonus faber Aida    GamuT S9
Cable	Cardas Clear

All things must eventually come to an end, but this time the breakup is not sweet sorrow.  Living with the Pass Labs XA160.5 Class-A monoblocks has been a wonderful experience, and the heat that these massive monoblocks let off is a small drawback compared to the glorious sound they produce.  In a year and a half of flawless performance, driving every kind of loudspeaker imaginable, I didn’t jot down a single complaint in my mental logbook.  The XA160.5s even proved more engaging than a number of vacuum-tube power amplifiers parked here for various reviews and personal auditions, supporting Nelson Pass’ claim that listening to his amplifiers are like “listening to tubes, but without the hassle.”

But then the XA200.5 monoblocks arrived.  “More devices and more power equals more control,” says Pass Labs’ Desmond Harrington when asked about the difference between the XA160.5, the XA200.5 and the soon-to-arrive XS amplifiers.  If there was ever a case of specs not telling the whole story, this is it.  You might think there would be barely any difference between these two amplifiers—one delivering 160 watts per channel and the other delivering 200 per channel—but fire up the drum solo in Zeppelin’s “Moby Dick,” and the XA200.5 paints an entirely different picture.  “Stairway” is pretty damn good, too.

Hey, Ho, Let’s Go

Tony Levin’s bass playing on the Black Light Syndrome album, from Levin, Steve Stevens and Terry Bozzio, illustrates this perfectly.  This album offers some of the heaviest prog rock available; a dense, driving orchestral soup in which these three virtuosos repeatedly lay down notes like they’re firing automatic weapons.  Levin is solidly anchored, while his bandmates careen off to the far edges of the soundstage from start to finish.  Keeping all three musicians straight without blur is a tough task, but the XA200.5s handle it effortlessly, even at high levels.

The low, grumbling undercurrent of Burial’s “In McDonalds” takes on a more visceral feel through these amps, helping the listener truly feel the track’s deep bass and low-level texture in a way few amplifiers can muster.  The overblown bass in Cash Money and Marvelous’ “Ugly People Be Quiet” loses none of its rawness and boom, while rumbling the woofers in the GamuT S9 speakers as if a subwoofer has been added to the system.  Many audiophile amplifiers suffer from too much control and damping in such instances, taking the soul of the music with it, but the XA200.5s are true to the music, no matter what the genre.  Even a lousy-sounding record like Teenage Fanclub’s Bandwagonesque is better sorted through these amps—this thick, compressed recording actually gives up some dynamics, with a little help from the dCS Vivaldi source.

With two pairs of world-class reference speakers at my disposal (the GamuT S9 and the Sonus faber Aida), these amplifiers play to a painfully loud level without distortion.  Whether using the S9 (89 dB sensitivity) or the Aida (92 dB), the XA160.5s can be driven to a point of compression; the XA200.5s have no limit in my system.  But man cannot live by bass alone—transient prowess is another area at which the XA200.5s excel.  Romping through the title track from Carsten Dahl’s Bebopish Rubbish Rabbit, these amplifiers provide not only control, but also acceleration.  They equally render drum transients and brushwork with the proper scale and finesse.

On one level, a component can really only be evaluated in the context of a system, and it’s tough to attach a sound to said component without seeing how it reacts to the known performance of a number of other preamplifiers and speakers.  Having lived with a variety of Pass amplifiers for a few years now, I would characterize their overall sound as ever so slightly on the warm and harmonically rich side of the scale.

The XA200.5, like all of the other XA-series amplifiers I’ve auditioned, paints a big, spacious, three-dimensional soundstage—again, much like your favorite tube amplifiers do, but with considerably more dynamics, grip and control.  On the title track from Leni Stern’s album Smoke, No Fire, the XA200.5s capture her delicate guitar playing with every bit of the gradation she presents in a live show, while layer upon layer of overdubbed vocals hang in mid air, meticulously spaced between each other.  Too often, mediocre solid-state amplifiers fail musically when presented with these kinds of recordings, because their inability to resolve spatial information results in an overly flat and sterile picture.  Modestly powered tube amplifiers excel at this kind of thing, but are unable to produce the giant dynamic swings required to capture a large orchestra or driving rock band.  The XA200.5s excel here, providing the best of both worlds.  Thanks to their massive power supplies and big banks of output transistors, these amplifiers retain inner detail while simultaneously carrying a heavy bass line or the roll of a kettledrum.

A is A

The Pass Labs website simply states in the FAQ section that the reason the company produces Class-A amplifiers is “because they sound better.”  I love this firmness of conviction.  I must also admit to a bias towards high-powered Class-A solid-state power amplifiers in the same way someone might prefer tubes, SET amplifiers or a pair of Quad 57s.  At the end of the day, we all have a preference, and I won’t apologize for this one.  Pass’ large Class-AB amplifiers, as well as a few other massive AB amplifiers I’ve experienced (like the Simaudio 880Ms also reviewed in this issue), still have slightly faster acceleration and ultimate dynamic swing, but this always comes at the expense of that last bit of inner sweetness.  That being said, one person will always prefer the slightly softer ride of a standard Mercedes to the AMG version with sport suspension.

Pass Labs’ relatively recent .5 series of Class-A amplifiers come as close to offering it all as anything I’ve experienced.  While I still treasure my Pass Labs Aleph 3 (from the ’90s) and Threshold 400A (one of Nelson Pass’ first Class-A designs from the late ’70s—also a big favorite), comparing them to the XA200.5s clearly illustrates where Mr. Pass has built on his initial strengths, constantly refining the sonic delivery of today’s models.

Romping through a plethora of recorded male and female vocalists underscores these amplifiers’ combination of power, delicacy and tonal accuracy.  Anne Bisson’s gentle vocal stylings on the title track of her recent Blue Mind album are reproduced perfectly though the XA200.5s, as are the piano and soft drum work that accompany her.  If not for the enormous heat sinks on the side of each amplifier, you’d swear that the grain-free tonal texture that the XA200.5s provide is due to some vacuum tubes inside the box.  And that’s the entertaining paradox:  These amplifiers have too much sheer grunt to be tubed.  Like Nelson Pass said…

Setup and Synergy

During our time with these amps, we had the opportunity to power about 30 different sets of speakers, from a pair of freshly refurbished MartinLogan Aerius i speakers to Sonus faber’s flagship Aidas.  Nothing poses a challenge to these amplifiers or affects their performance.

The amp’s balanced XLR and single-ended inputs have an impedance of 30k ohms, which makes them easily mated to the preamplifiers at our disposal from Audio Research, Burmester, Conrad-Johnson, Robert Koda and Simaudio.  Cardas Clear cabling was used for the bulk of our listening tests, yet both speaker cables and power cords affect the XA200.5 less than many other high-powered amplifiers in recent memory.

One thing the XA200.5s benefit from, if you have the luxury, is dedicated power.  Drawing 700 watts each all the time, they will work connected to a standard 15-amp circuit, but will work better with a 20-amp line and better still with a pair of dedicated 20-amp circuits—one for each amplifier, if you really like to twist the volume control.  I’d suggest having your electrician install a pair of 20-amp outlets for your XA200.5s before you drop a few thousand dollars on exotic power cords.

Fortunately, these 159-pound monsters have conveniently placed handles on the rear panel, though (unless you’re incredibly buff) you will still need a friend to help you unpack these amplifiers.  Once you’ve installed the amps, be sure they have plenty of ventilation, because they do get warm.

The Big, Big Money

This extra power and control doesn’t exactly come cheap.  The XA200.5s have an MSRP of $34,100 per pair, compared to $24,000 per pair for the XA160.5s.  It’s always easy for me to spend your money, but if you can find a way to come up with the extra $10,000, you will not be disappointed—this is truly a case where absolute power corrupts absolutely.  The XA160.5s are no slouch by any means, and tonally identical to the XA200.5; yet, even at modest volume levels, the effortlessness provided by the bigger, beefier output stage and larger power supply is instantly evident.

If you are looking for a pair of monstrous Class-A amplifiers that take no prisoners, consider the Pass XA200.5 monoblocks, or stick around for a few more issues—the XS two-box monoblocks have just arrived for review!

Pass Labs XA200.5 Monoblocks

MSRP: $34,100 per pair

www.passlabs.com

Peripherals

Analog source	AVID Acutus Reference SP turntable    TriPlanar tonearm    Lyra Atlas cartridge    AMG V12 turntable    AMG tonearm    Clearaudio Goldfinger cartridge
Digital source	dCS Vivaldi    Meridian Sooloos Control 15    Aurender S10
Phonostage	ARC Reference Phono 2 SE    Indigo Qualia
Speakers	GamuT S9    Sonus faber Aida    Sonus faber Elipsa SE
Cable	Cardas Clear
Power	IsoTek
Accessories	Furutech DeMag and DeStat    Audio Desk Systeme RCM    GIK room treatments

As class-D amplifiers continue to evolve, it’s exciting to have the opportunity to test examples such as IQ Audio’s new monoblock, dubbed the M300. While each M300 is very compact—7.75 inches wide, 7.75 inches deep and a 3.25 inches tall—the amps should not be taken, well, lightly.  Their physical size-to-sonic-punch ratio makes them a bit like the Sugar Ray Leonard of the amp world.  The M300s deliver a hefty 150 watts into 8 ohms, and 300 watts into 4 ohms.  According to IQ’s literature, the M300s can also handle loads in the 2-ohm range.  So at this price point—$1,495 per pair—you get a lot of watts per dollar.

Weighing In

My lower back confirms that the modest dimensions of the M300s make them a cinch to move and integrate into my audio system.  At a mere 7 pounds apiece, the M300s are easily tucked under each arm, leaving me with spring in my step as I move them to the listening area.

A Mark Levinson No. 335 amplifier, which weighs a spine-warping 150 pounds, normally inhabits the lowest shelf in my audio rack.  I prefer not to move this behemoth out of the way for review equipment if I can avoid it—as long as my guest amplifiers have a place that allows them good ventilation and vibration control.  The M300 packs a lot of technology into a small package. The M300 uses a software programmed micro-controller input and buffer stage, and a SMPS power supply that enables the M300 to deliver FTC rated power into both 4 and 8 ohms, i.e. not just peak power.

The tiny size of the M300 offers many placement options that larger amps do not.  In my case, each amp has a temporary residence perching atop a 26-inch-tall bookshelf speaker stand.  These improvised amp pillars present each of the M300s quite nicely as they display the subtle blue LED power-up ring complementing the amps’ matte-black facades.  After a few minutes examining and admiring my sonic visitors, the process of connecting them to the rest of the system begins.

Against the Ropes

The M300s use the manufacturer’s IQ-torque binding posts, which enable easy and solid connections for spade speaker-cable terminations. It’s worth mentioning that these binding posts are similar to the ones used on much more expensive Boulder and Pass amplifiers, and so much easier to work with than those plastic coated ones featured on many amplifiers today. IQ principal Bruce Weisberg mentions that they chose these binding posts for their sonic qualities as much as convenience – a nice touch for a $1,500 pair of amplifiers. Rather than twisting a small 5-way binding post by hand and then tightening it further with a post wrench, I’m able to easily tighten the M300s’ large key-shaped posts without using extra tools.  As I twist the posts, I can’t help but recall some of my favorite childhood wind-up toys.  Gentle ribbing aside, I personally love the choice IQ made with these posts and the firm connection they facilitate.  Once they are cranked down, nothing is coming loose.

However, this connection type may present a problem for some users:  First, there is no accommodation for banana plugs; and second, with such a low amp height, there is little space between the binding posts and the surface the amp rests on.  As a result, thick cables may require mounting to the binding post in a way that leaves the cables pointing outward or upward from the amp, providing the M300 with something of a rooster-tail.  With that in mind, other users may find that speaker stands like mine aren’t such a bad idea.

Accompanying the binding posts on the back panel of each amp are both RCA and balanced inputs, as well as plenty of room for the power cable of your choice and two 12-volt triggers.  Because of their versatility, these amps can evolve with your system as you acquire or replace new components. And the M300 comes with the IQ-kord power cable, which is a 15A power cable featuring hospital grade IEC plugs and EMI / RF isolators.

And for some economic and environmental peace of mind, the M300s have an Energy Star–rated efficiency.  They do not get warm and the power-handling technology that IQ built into them enables them to consume very little power while at idle.

Ring the Bell

The first thing you notice sonically about the M300s is the non-fatiguing way they present music.  Regardless of musical genre, the M300s avoid stridency.  They render jazz, classical, rock, and electronica very well, allowing the listener to sit back and enjoy the musical experience without the “wince factor” that some equipment creates.  I put these amps through the Four Johns test—that is, listening to Cash, Coltrane, Digweed and Philip Sousa—and the music retains the heart of the performances without harsh sonic artifacts.

The M300s bring to life the guitar plucks on “Give My Love to Rose,” from Johnny Cash’s American IV, with delicacy and richness.  While the amps tend to place the vocals into the mix a bit, they do render the song’s emotional content very well, accurately portraying the age and gravelly roughness in Cash’s voice.

They also render John Coltrane’s saxophone with clarity and grace.  Those who have sat near a live saxophone performance know that the sound can have a natural sharpness in some cases.  The M300s manage to reveal the detail of Coltrane’s performance without adding any harshness beyond that already inherent in the recording.  Through the M300s, the jazz legend’s album Blue Train is both engaging and relaxing.

Ready to Rumble

Fans of electronica know that bass punch and depth are necessary to get people out on the dance floor.  IQ claims a frequency response of 5 Hz to 45 kHz for the M300s, plus or minus 3 dB.  As I’m not able to get the dog next door howling at notes beyond the upper range of my hearing, I can’t verify sound above 20 kHz.  I can say with conviction, however, that the bass indeed goes very deep.  In addition to low-frequency test tracks verifying an audible and tangible 20 Hz rumble in my room, John Digweed’s remix of “Warung Beach” illustrates the M300s ability to provide plenty of get-up-and-go.

Recordings of “The Stars and Stripes Forever” conducted by John Philip Sousa offer varying degrees of audio quality, so I cheat a bit on my theme by deferring to recordings by modern conductors.  Here, the M300s do a very nice job of revealing the dynamic contrasts of the various instruments.  Flute notes dance through the air with delicacy; cymbals have a solid crash and a slow decay; and brass instruments are easily identified.  In a recording like this, adequate power is necessary to get the heft of the performance through my speakers—and the M300s do not disappoint.

Facing Heavyweight Contenders

So what’s the downside?  Unfairly comparing the M300s with my $8,000 reference amplifier (over five times the price of the IQ pair) reveals a few shortcomings that seem aptly illustrated with an analogy:

Viewers can appreciate Monet’s lily paintings differently depending on their distance from the canvas.  At 20 feet away, the colors, shapes and scenery are pleasant to experience as a whole.  But when viewed from just a few feet away, the painting’s impressionistic brush strokes reveal a texture and detail not detectable from further away, allowing for a deeper and more nuanced level of appreciation.  Once seeing the painting up close and in person, it’s difficult to appreciate scaled-down images of the same painting in a book, which do not portray the detail that you know is there.

Similarly, the M300’s sonic portrayal places the listener a metaphorical 20 feet from the music, leaving him or her a well-rendered sonic picture, but one that lacks some of the detail that my reference amp provides: organic realism, pinpoint imaging, a three-dimensional soundstage with width and depth, ambiance and front-to-back layering of instruments and vocals, along with a very quiet, black background.

While the M300s do an exceptional job delivering very deep bass, these low-register responses are not as tight, defined or tuneful as those delivered through my reference amp.  Again, these characteristics are something I’d expect from amplifiers at a higher price point.  I do not expect the same level of quality from a pair of monos in the $1,500 price range.

The Verdict

For everything that they do well, the M300s provide great value.  IQ made smart decisions in the designing and voicing of these amps.  They offer durable ease of use, stellar energy efficiency, enjoyable and non-fatiguing portrayal of music, the power needed to drive challenging speaker loads, and a neutral sonic profile that renders all types of music quite well.

At $1,500 per pair, the M300s are certainly worth an audition.  And the great news is that IQ sells direct from its website and stands squarely behind its products with a 30-day audition period for anyone who makes a purchase.  With this risk-free guarantee, why not decide for yourself if the M300s are a good fit for your system?  For this price, I think you’ll find that this pair of amps is a knockout.

Additional Listening

By Jeff Dorgay

Rob has made excellent points, and after some time with these tiny amplifiers, I concur with his assessment.  However, here are a few more points to ponder:

When purchasing a power amplifier in the $1,000-to-$2,000 range, there are always tradeoffs to be made.  And though there are a few integrated amps, like the Naim UnitiQute or the Rega Brio-R, that come across as slightly more palpable—especially through the midband—there’s no substitute for cubic inches (or, in this case, power).

More power on tap gives you more speaker options.  The M300s can drive a pair of Magnepan MMGs or 1.6/1.7s, while the two others either can’t (Naim) or only can to a point (Rega).  Sure, Class D amps, while having come a long way tonally in the last few years, can still sound a little sterile—and there’s nothing like a great tube preamplifier to warm that up a bit.  The IQ 300s actually use selected discrete mosfets in the output stage, another contributor to their musical nature. So I did just that, with the recently rebuilt Conrad-Johnson PV-12 and its full compliment of CJD Teflon capacitors under the hood.  The extra body of an older tube pre like this one goes a long way to bridge the timber gap between the M300s and my Magnepans.  The result sounds fantastic, especially in light of the M300’s price.

IQ Audio M300 Monoblocks

MSRP: $1,495 per pair

IQ Audio Corporation

www.iqaudiocorp.com

Peripherals

Speakers	Piega P10
Amplifier	Mark Levinson 335
Preamplifier	Coffman Labs G1-A
Analog Source	Marantz TT-15
Digital Sources	Audio Research CD3 MKII    dCS Purcell processor    EAD 9000 MKIII DAC   Genesis Technologies Digital Lens
Cables	Jena Labs Valkyrie and Symphony interconnects    Jena Labs Twin 15 speaker cables
Power Conditioner	Running Springs Audio Haley
Power Cords	Cardas Golden and RSA Mongoose
Accessories	Mapleshade SAMSON racks and shelves    ASC TubeTraps    Cathedral Sound room-dampening panels

Merely mentioning that you still listen to vinyl records in casual conversation amongst non-audiophiles almost always invokes a raised eyebrow. And if you try to explain the thrill of vacuum tubes, people that don’t give you a dog-like stare will surely move you to the penalty box. But as vacuum tube fans know, current designs continue to advance like the Energizer bunny, with the best examples light years ahead of the humble beginning of the Williamson circuit from the 1940s. In 1955, the Heathkit version of the original circuit claimed to have “performance far beyond the finest speaker systems available.”  Much has improved since then.

Hailing from Germany, the Octave MRE 130 monoblocks look straightforward in terms of aesthetics. But they’ve also combined a few unique features, along with meticulous attention to detail, to create a pair of power amplifiers that sit at the top of their class. The standard MRE 130 monos run $16,000 per pair, and thanks to external power supply modules ($7,500 additional per pair), allow for the option of taking their stunning performance even further.

The most distinctive aspect of these amplifiers is the substantial redesign of the classic pentode amplifier circuit. The first part of the Octave approach is its power management system, which not only provides a soft start for the tubes, but also furnishes a separate supply that is optimized for the input stage—as well as another for the output stage and a third section that takes care of the additional current requirements of the pentode circuit. In addition, an electronic protection circuit protects the amplifier from damage, should tube failure occur while remaining audibly transparent.

While Octave has only been distributed in the United States for a few years, the company began in 1968 when founder Andreas Hoffman’s father began a transformer-winding factory in Germany. Hoffman started building solid-state amplifiers in 1975 and turned his attention to tubes in 1977. In the years that followed, his products won numerous awards in Europe and Asia.

The MR 130 amplifiers are rated at 100 watts per channel into an 8-ohm load and 130 per channel into 4 ohms. Available in silver or black, the MR 130s are substantial at 46 pounds (22.7kg) each, but not so heavy that they need more than one person to lift.

Setup

Removing the tube cage reveals a complement of two 12AU7s (ECC82C) and a 6C5 as driver tubes, with a quartet of 6550s for the output stage. They can also be configured with KT88s. The review pair came with KT88s installed, and Octave was thoughtful by including two spare power tubes. The company should also be praised for producing one of the most comprehensive and well-written manuals in the industry. It offers background on the design, a thorough explanation of how to properly bias the tubes, and finally, for the technically inclined, measurements.  Hoffman has indicated that future versions of the MRE 130 have been slightly modified to ship with a 6SN7 in the place of the 6C5, to make it easier to find replacments, but assured me that there is no change in sound.

Once the tubes are installed in their respective sockets, the output tubes need to have proper bias set. Five LEDs indicate bias status. A middle green LED indicates correct bias, while a yellow one to the left of center glows with an underbias situation and a yellow one to the right indicates overbias. An orange LED all the way on the far left is used when installing a fresh set of tubes. Finally, a red LED on the maximum far right position only lights when a tube is defective.

The remainder of the setup is straightforward, with two pairs of easily accessible speaker binding posts and a pair of RCA and XLR input sockets. Input type is selected via a switch, and the inputs can be shorted as well, so you can change cables without causing amplifier or speaker damage. XLR connectors are offered, but the amplifier is not fully balanced, as Hoffman doesn’t feel that it’s a superior way to design a tube amplifier.

Although the manual states that output tubes can take “up to 300 hours to sound their best,” my review samples had just come from the Rocky Mountain Audio Fest, where they had about a week on the clock. I did not hear a change in amplifiers’ sound character during the test period, other than that of initial warm-up. The MRE 130s require about 45 minutes to sound their best.

It’s also worth mentioning that an output tube failed during the course of this review, and while such an episode may have caused drama with other amplifiers, the MRE 130 simply went quiet. The corresponding red LED lit up to indicate the defective tube. Once the latter was replaced, the MRE 130 went back to performing flawlessly.

Listening Impressions

Beginning with a handful of audiophile classics, I was instantly struck by the soundstage depth and fine detail offered by the MR130s. The LP of the Fleet Foxes’ debut encapsulated such characteristics, keeping the band members’ harmonies wonderfully separated. And the title track from the new Fleet Foxes record, Helplessness Blues (reviewed this issue), proved quite a treat as well. The heavily layered vocals were easy to pluck from the main musical line, as they floated above and in front of the big bass drum in the background.

John Fogerty’s version of “I Put a Spell on You” from Creedence Clearwater Revival’s self-titled album (45RPM Analogue Productions version) proved equally captivating. Shortly thereafter, the band’s “Suzie Q” equated to retro treat, with the lead guitar distinctly defined in the far left channel, full of glorious distortion as Fogerty chimed in and out of the right channel. Yet the bass guitar sounded diffuse, hanging back behind the performers. It was as if bassist Stu Cook was off playing in another room.

While most tube amplifiers impart a glorious sense of pace and a generous measure of air, they usually falter in the area of bass control. But the MRE 130s did not fall victim to the common problem that plagues all but the world’s best tube amplifiers— proof that Hoffman’s power-supply design is highly successful. The funky bass lines in George Michael’s “Hard Day” from Faith arrived with just the right amount of weight and grip, and without losing control. Keep in mind that this song usually overwhelms most tube amplifiers and ends up boomy.

I was equally impressed with the deep bass performance of the MRE 130s when grooving to George Clinton’s “Why Should I Dog You Out?” from The Cinderella Theory. If you have speakers capable of delivering major low-frequency extension, the MRE 130s will step up to the plate. Depth and dimension were definite specialties of the MRE 130s even if they weren’t the equivalent of my Burmester 911 mk.3s. But the Octaves were about to make some big performance gains.

Increasing Performance: Step One

Users not interested in experimenting with different tube configurations will enjoy the MRE 130s as outfitted at the factory. However, if you are a maniacal tube enthusiast that always searches for more performance, rest assured that more is on tap. Towards the end of the review period, the new KT120 power tubes were released. And while this model isn’t a plug-in replacement for every amplifier that utilizes 6550 or KT88 tubes, Hoffman assured me that the MRE 130s’ power supply was up to the task of this particular tube’s increased current demands.

Hoffman also claims that, without redesigning the amplifier, it really won’t produce much more power than with the stock KT88 tubes. Yet, with the KT120s installed, the sound quality tremendously improved on both ends of the frequency spectrum. Bass became deeper and tighter, with even better control than before. The MRE 130s already exhibited some of the most controlled bass I’ve ever heard from a tube amplifier, and with the KT120s, they offer even more grunt.

At the other end of the spectrum, more air circulated around cymbals than before.  Heading back to the CCR catalog, the high hat cymbals seemed to float better while the overall sound achieved a heightened level of refinement. Acoustic instruments became fleshed out with more body; the more complex sounds of the violin and piano took another step towards reality. Originally recorded to two-track 30 i.p.s. tape, Liz Story’s Steinway on her Solid Colors LP suspiciously sounded like the one in my living room.  The amplifiers did an excellent job of letting me just forget about the gear and get lost in the musical presentation.

While the MRE 130s came with a pair of JJ ECC82s (12AU7) installed in each unit, swapping them out for the new Pvane 12AU7s from Shunuang yielded more delicacy. Substituting your favorite NOS tube may change the tonal character of the amplifier, but the new Pvane tubes did not alter tonality. They simply dropped the noise floor of an already very quiet tube amplifier even further, and peeled off a layer of grain that I didn’t previously know existed.  If you do nothing else to your MRE 130s, I highly suggest making this small change.

Step Two: Adding the Big Black Boxes

After becoming thoroughly familiar with the MRE 130s in their stock form and then again with upgraded tubes, another big performance jump came via the Super Black Box, which incidentally, is silver. While a pair of Super Black Boxes add $7,500 to the MRE 130s’ price tag, the improvement is major—and well worth it. As you might suspect from such a substantial upgrade, the soundstage immediately became larger in all three directions, the upper register had more clarity, and the bass possessed even more heft and control.

Whereas Naim gives you the opportunity to add a completely different power supply, the Octave Super Black Box is a giant capacitor bank tethered to each amplifier by a massive power cord and connector. Once powered up, the Super Black Box has a blue status indicator—just like the power amplifier. Should you feel the need to disconnect them, a yellow LED glows for approximately two seconds, indicating the discharge. Hence, you will not be exposed to any harmful voltage when unplugging them.

Digging through deep tracks to locate old-school synthesized bass, I dusted off Edgar Winter’s Jasmine Nightdreams. The second cut, “Little Brother,” has a fairly loose and whumpy albeit powerful bass line that was much more agreeable with the Super Black Boxes in place. The song lost some looseness but not the character of the bass.  I discovered the same effect when playing “Word Up!” from Korn’s Greatest Hits, Vol.1. The driving bass line attained more authority and punch than before, an experience that led me to revisit most of the initial tracks I used to determine the MRE 130s’ character. A definite transformation.

Still, the improvements afforded by the Super Black Box went beyond bass performance. The three-dimensional aspect of the presentation increased to the point that I felt as if I were listening to surround sound. Kraftwerk’s Tour de France took on an uncanny sense of depth that normally requires an analog source to achieve. I found myself listening start-to-finish to several albums in the digital format that I normally experience one or two tracks at a time before moving on. The MRE 130s’ resolution healthily expanded, as did the jump in dynamic range.

Hoffman also told me that one of the side benefits of additional power-supply capacity lowered the amplifier’s output impedance, which accounts for its spectacular bass performance. Such extra capacity also gives the MRE 130s’ the ability to more easily drive difficult loads. I had no problem driving my MartinLogan CLX speakers or the Magnepan 1.6s, each notoriously tough to drive with tubes. Without the Super Black Boxes in place, the MRE 130s ran out of juice with the Magnepans and rolled off the highs with the CLXs. This upgrade is a must if you plan on using these amplifiers with either speaker.

Before adding the upgraded tubes and Super Black Box, the MRE 130s took a back seat to my Burmester 911 Mk. 3 monoblocks in terms of imaging and delicacy. But, after I made the changes, the Octave units held their own in these areas when played within their limits—very impressive for a pair of amplifiers that cost one-third as much as the Burmester gear.

Conclusion

While I can’t imagine using the Octave MRE 130s without the Super Black Boxes now that I’ve had the experience, they are fantastic amplifiers without the add-ons, and Octave is to be commended for giving the end user the opportunity to work their way up to a statement product.

The Octave MRE 130 monoblocks should satisfy all but the most power-hungry systems. If 130 watts per channel is not enough, Octave also produces floor-standing Jubilee monoblocks, which we will audition in the near future. If you’ve always wanted the benefits of tube amplification without any of the drawbacks, these amplifiers are for you.

Octave MRE 130 Monoblock Amplifiers

MSRP: $16,000/pair; Super Black Box: $7,500/pair

www.octave.de

Peripherals

Analog Source	AVID Acutus Reference SP w/SME V and Koetsu Urushi Blue
Digital Source	dCS Paganini (4 box stack)    Sooloos Control 15
Phono Preamplifier	ARC REF Phono 2    Octave Phono Module
Preamplifier	Burmester 011    McIntosh C500
Speakers	GamuT S9    MartinLogan CLX    Magnepan 1.6    B&W 805D
Cable	Cardas Clear
Power	Running Springs Maxim and Dmitri power conditioners    RSA and Shunyata power cords
Accessories	Furutech DeMag    SRA Ohio Class XL+² equipment platforms   Loricraft PRC -2 record cleaner

Red Wine Audio founder Vinnie Rossi has built a solid reputation on battery-powered gear, utilizing LiFePO4 cells with his unique SMART battery management that eliminates the headaches of batteries, while providing the maximum life and performance that this technology can deliver.

His lower powered Signature 15 and 30.2 amplifiers have won awards and acclaim the world over for a smooth sound that sounds neither tube nor transistor-like, and are dead quiet, eliminating the interaction with the power grid.

Having used Rossi’s amps for some time now, I’ve always felt they were very special, but often thought,  “if only they had a bit more power…”  With the Liliana, the dream is realized.  A Class A 6922 input stage drives a Class AB MOSFET output stage to the tune of 115 watts into 8 ohms, doubling to 230 watts 4 ohms.  Serious power.

If you are a current RWA amplifier owner, a quick peek at the website reveals a healthy trade up program, should the urge to upgrade strike you.  RWA warranties all of their products for five years, and a few TONE readers that have had minor issues have confirmed that Rossi’s service department is helpful and quick – A testament to the tremendous owner loyalty that RWA enjoys.

This new design has scaled up perfectly; nothing in the sonics department has been compromised.  Previous RWA owners will notice the same delicacy from previous models, but the additional power opens up the door to more speaker options.  Pairing the Lilianas with the $120,000/pair Sonus faber Aida is a fantastic match, immediately underscoring that these amplifiers are of top quality and able to be installed in the context of any system. Though the RWA amplifiers give up a little bit of grunt to the Pass Labs XA200.5 monoblocks, there is a clarity in the upper registers very similar to what Pass is doing with their First Watt amplifiers.

Grain free sound

If the RWA amplifiers can be said to possess a “sound,” it’s a lack of the grain that creeps into components that are tethered to the AC line.  I’ve managed to eliminate this from both of my reference systems, but at great cost in massive power cords and power line conditioners.  I’ve even used one of RWA’s Black Lightning battery supplies with various Nagra components, achieving similar results.  I also currently have another Black Lightning on order for the rest of my components running on 12 or 24 volts DC.

As Trey Gunn’s “The Joy of Molybdenum” hits the Aidas, I’m instantly convinced that these amplifiers are indeed very special.  This is a dense recording, with some rapid-fire riffs from Gunn, backed up with a solid bass fundamental.  Even at high volume, the Lilianas keep their composure and preserve the three-dimensional soundstage present on this recording.

Plumbing the depths of just how much bass these amplifiers can muster, a quick speaker swap from the Aidas to my reference GamuT S9s, which are a bit easier to drive and slightly less current dependent is telling.  Here, going through a set of Prince tracks, spanning the generations proves that they can go down very deep.  “Insatiable,” from the Diamonds and Pearls album begins with a subterranean, loose, whumpy, synth bass line that is tough for any amplifier – yet the Lilianas keep their composure and handle this torturous track brilliantly.

Mark Ribot’s “Requiem For a Revolution,” from his current Silent Movies album is chock full of texture, with dexterous guitar work from Ribot.  If you’ve had the opportunity to see him recently, you know the fire that he brings to a live performance, full of nuance and emotion.  The Lilianas ability to capture low-level detail clearly makes it easy to close my eyes with the mighty GamuTs and imagine I’m back in the main hall at the Montreal Jazz Festival again.  And of course, those of you that crave female vocals will not be disappointed.

Listening to a cross section of acoustic music, both jazz and classical through the Dynaudio Confidence C1 II speakers in room two proves equally rewarding.  The Lilianas have an excellent sense of pace and timing, combined with tons of texture.  Cymbals sound as they should, with plenty of attack and texture.  An old favorite on vinyl, The Three, featuring Joe Sample on keyboards and Shelly Manne on drums is a direct to disc LP that has some of the cleanest cymbal sounds ever captured to vinyl.   Lee Morgan’s Tom Cat is another great example, with some fantastic brush work on the drums.  Instead of just sounding scratchy, the RWA amps flesh out the texture perfectly.

One of the greatest advantages to using a pair of monoblock power amplifiers is the additional channel separation.  Combining this with a complete lack of electrical interaction because of the battery power makes for an otherworldly stereo effect.  I found when listening to the Dynaudio monitors, the Penaudio Cenyas or the MAD 1920s, the surreal mini monitor effect, that of listening to gigantic headphones in your listening chair was further heightened.  Taking inventory of some ambient and techno tracks from Eno, Deadmau5 and Tosca proved trippy.  Tosca’s “Me and Yoko Ono” was pure pleasure, with instruments and environmental sound bits everywhere.

At the edge

The only place the Lilianas give up a little bit of ground is when being pushed beyond reasonable and prudent levels.  When the Lilianas are pushed to their power limits, the soundstage just flattens out somewhat, instead of the sound becoming grating or harsh.  Even operating at brain damage levels, the Lilianas do not generate much heat and are still only lukewarm to the touch.

However compared to other things in their power and price class, they come through brilliantly, and we probably shouldn’t be playing Van Halen that loud anyway.  230 watts into 4-ohms is still really not enough to drive the Magnepans to major volume, but the Lilianas prove an exquisite match for the MartinLogan Montis speakers we recently reviewed.  The speed and low-level detail that the battery power brings to the table is just what the doctor ordered.

Life off the grid

RWA claims 6 – 8 hours before these amplifiers need to be recharged, which is best done overnight.  The LFP batteries do not have a memory effect, and even after months of charge and recharge cycles, they still manage to play for very close to 8 hours without fail.  For everyone but me, who has their system on for 12-14 hours a day, this should be more than enough time for serious listening.  If you lose track of playback time, when the amplifiers run out of battery power, they just turn silently off, without any annoying clicks, pops or anomalies.  Click the front panel switch back to the charge position (or On/Charge to play via the external charger providing power from the grid).

Thanks to the SMART battery management, you can leave the chargers connected permanently.  They automatically switch out of the circuit when playing in pure battery powered mode.  Considering the amount of money you will save not purchasing a pair of premium power cords, a power line conditioner or a fancy AC outlet, the $6,000 price for a pair of Lilianas is not so crazy after all.  Not being limited by power cord and outlet choices also gives you more flexibility when choosing the location for your RWA amplifiers.

Setup

The Lilianas are easy to integrate into your system.   They do feature single ended RCA inputs, but I had no problems using them with a fully balanced preamplifier like the ARC REF 5SE or the Burmester 011 through either the balanced outputs (via an adaptor) or the RCAs.

The RWA logo on the top surface of the amplifier is functional as well as decorative.  There is a glass window that rotates out of the way, allowing easy access to the 6922 driver tube inside, making it easy for those that like to roll tubes.  Needing only one per monoblock, you can try some fairly exotic tubes without breaking the bank.  I had a friend drop by with a pair of NOS Telefunken CCa tubes that are probably one of the most rare and expensive varieties, to great result.  The Lilianas got sweeter through the midrange, though at the expense of a bit of the LF weight – yet this is a fantastic way to fine tune the amplifiers to your speakers and your taste.

The stock tubes are great all-rounders, offering an excellent balance between low noise and linear frequency response.  However, those requiring a bit more “tube magic” can choose their favorite NOS tube to voice the amplifier as they see fit.  The glass window glows red until the tube has warmed up, which takes about 45 seconds.

A sound choice

The Red Wine Audio Liliana monoblocks will make an excellent addition to your system.  They feature neutral tonality, speed, dynamics and low level detail retrieval that few amplifiers in their price category can match.  Combining that with their compact size and minimal power requirements for charging the internal battery, these are a fantastic pair of amplifiers that will serve all but the most power hungry speakers.  Best of all, RWA offers a 30-day refund period should you find that they aren’t the perfect dance partners for whatever reason.  Highly recommended!

The Red Wine Audio Liliana Monoblock power amplifiers

MSRP:  $6,000/pair

www.redwineaudio.com

Peripherals

Analog Source	AMG V-12 turntable, Clearaudio Statement cartridge
Digital Source	dCS Paganini stack, Sooloos Control 15, Aurender S10
Phonostage	Simaudio MOON 810LP
Preamplifier	ARC REF 5SE, Burmester 011, Robert Koda K-10
Speakers	GamuT s9, Sonus faber Aida, Dynaudio Confidence C1, MartinLogan Montis, Quad 57, Penaudio Cenya
Cables	Cardas Clear
Accessories	Furutech DeMag, DeStat, GIK acoustic treatments

Throughout his career, Bob Carver has made several legendary products and, like most great artists, stirred up controversy in the process. His new line of tube amplifiers aren’t just brilliant, they’re reasonably priced. For those wanting the “Made in America” badge, these crimson beauties—along with every other Carver amplifier—are built by hand in Lexington, using point-to-point wiring techniques.

The VTA180M features a simple and honest design. Its basic, open chassis configuration adds to the vintage feel and keeps costs manageable. You won’t mistake these units for a pair of megabuck tube amps machined from solid billets of aluminum. Well, not until you turn them on. Then, be prepared to be pleasantly surprised.

Having sampled many great tube amplifiers over the last few years, I was immediately impressed by the VTA180M’s level of detail and grunt provided by the 200 watts-per-channel reserve. Vide, Bombay Dub Orchestra’s 3 Cities. This record serves up big, synth-bass beats that challenge any amplifier driving full-range speakers. The Carvers reward my GamuT S9s (that have a -3db point of 17hz) with solid, texture-laden bass and subterranean extension.

They also require little warm-up time. With just a half hour on the clock, the amps piqued my interest when playing Chemical Brothers’ “Galvanize” from Push The Button. The assault of bombastic bass waves encouraged me to twist the volume control to nightclub-like levels. As the GamuT S9s’ six 11.5-inch woofers pumped, I felt like the guy in the Maxell chair, with the system moving major air sans strain or distortion. The amps sound enticing even after the first five minutes, but require 45 minutes to thermally stabilize and reach full bloom. Once there, an enormous, three-dimensional soundfield awaits. Vacuum-tube newbies will experience an entirely different sonic landscape.

Midrange Options

Reach-out-and-touch-it midrange is almost always a given with tube amps; the extra airiness draws music lovers to vacuum tubes. The VTA180M lets you pick a preferred presentation, offering two feedback settings: 11db (contemporary amplifier) and 20db (classic amplifier) that affect the upper bass/midrange presentation. According to the concise instruction manual, Carver leans toward the classic setting, and it’s nice to have the option. Plus, you can switch the setting on the fly without suffering any annoying or potentially harmful pops.

The extra feedback provides a warmer, more saturated sound, much like many beloved vintage tube amplifiers. Meanwhile, the 11db setting possesses a punchier sound and tighter bass response. It’s also great for fine-tuning an amplifier to speakers. So, even if your taste in speakers changes, your amplifier can remain in the system. This is a great way of making the VTA180Ms obsolete-proof. One note: Should you have a pair of speakers that already have a bump in the upper-bass/lower-midrange region, a romantic-sounding tube amplifier can be too much.

In addition, you can use the feedback switch as a tone control. Regardless of your system’s overall tonal balance, if you listen to a fair amount of MP3s via MOG, Spotify, or another online service, extra tonal warmth supplied by the VTA180M in the classic amplifier mode goes a long way towards making harsh digital sources more listenable.

For Those About to Roll

Tube rolling with the VTA180M is effortless. Its open casework allows easy access. The stock tubes sound awfully good, so your degree of OCD will determine whether they constitute the equivalent of a quick jaunt down the bunny hill or a Double Black Diamond run. Should you swap them out, you will need a dozen power tubes—not for the faint of checkbook. A set of Gold Lion reissued KT-88s imparts a less grainy feel, and sacrifices nothing in the top and bottom ends of the frequency spectrum. Just be sure to check the front-panel bias meter and adjust accordingly when fitting a different set of output tubes. Again, the Carver manual goes into great detail explaining the process and makes it all simple.

Experimenting with the 12AX7 input and the 12AT7 pre-driver tubes offers a wider range of tonal change than fiddling with the output tubes. With only one of each tube per monoblock, it’s a basic exercise. While NOS 12AX7s can soar as high as $300 each (for super high-zoot Mullards and Telefunkens), Mullard 12AT7s rarely top $30.  The 12AX7 is the tonemeister: Changing it affects overall tonality as much if not more than the feedback switch. Or, you can just leave the VTA180M stock and enjoy as is. Or can you? Decisions aside, Carver offers an impressive one-year warranty on the factory tube set and seven-year warranty on the amplifier.

The Whole Enchilada

Tube amplifiers live and die on the top and bottom of the audio spectrum. Some offer a dreamy, creamy, albeit slightly rounded off high-frequency response, a trait especially attractive to digital music collections. Other units put forward a very refined, extended, clinical sound that gets so close to the character of solid-state gear, one ponders why valves were ever chosen.

The VTA180Ms provide excellent overall tonal balance, regardless of feedback setting. Low-end extension is particularly healthy. Tube amplifiers rarely possess great bass texture, yet the VTA180M excels in this region. Tom Petersson’s bass on Cheap Trick’s self-titled album enjoys alluring growl. The opening bass riff on “Mandocello” bites and feels natural. As his hand slides up the instrument’s neck, it sounds like you’re standing in the front row of a small venue peering right at a big Ampeg bass cabinet. A similar experience occurs with an early British pressing of the Beatles’ Revolver. Even at high volume, Paul McCartney’s bass line stays solid and easy to follow, with plenty of definition.

Things are equally good up top. Without surrendering any tonal saturation, the VTA180M provides a clean, resolute high end. Cymbals are portrayed with plenty of air and texture, feeling neither rolled off nor exaggerated. Switching back to a few vintage amplifiers on hand from Dynaco and Marantz reveals similar tonal saturation, but to the point of obvious coloration and grain, particularly when listening to Joe Sample and Co. on The Three, an incredibly well-recorded direct-to-disc LP. Shelly Manne’s drumming loses the air present via the Carver, through which the percussion sounds like real cymbals.

When spinning Revolver, the background handclaps in “And Your Bird Can Sing” are not as prominent as it is with the best amplifiers at my disposal. This slight loss of ultimate low-level resolution, in comparison to that delivered by big-dollar gear, is the VTA180M’s only apparent weakness. But these cherry-red monoblocks do everything else so well, you won’t notice it.

The VTA180Ms feature a single-ended RCA input and work flawlessly with the handful of on-hand preamplifiers from Audio Research, Conrad Johnson, Burmester, McIntosh, and the new Coffman Labs model currently under review. Thanks to 2-, 4- and 8-ohm output taps, the Carvers show no problem driving the MartinLogan Montis speakers and even produce enough juice to drive the Magnepan 1.7s to fairly high levels.  If you are nervous that the rated 230 watts-per-channel isn’t enough for your Magnepans, Carver’s VTA305M monoblocks should get you there.

Award Winning Performance

I am very excited about the VTA180M amplifiers. Designed by a legend, they offer a no-nonsense approach, with money spent in the right places. We could talk in circles about parts and topology choices, sure. But in the end, these amplifiers do everything well, volunteering a sensory experience that normally commands a higher price.

Indeed, this is a tube lover’s pair of amplifiers. They provide more than enough power to drive all but the most inefficient speakers, and boast an extraordinary level of refinement. The ability to drive low-impedance loads, as well as the option to change feedback and alter the amps’ character to suit personal tastes, are bonuses.

If there’s a better pair of 200-watt-per-channel tube amplifiers out there for this kind of money, I haven’t heard them yet. The Carver VTA180M monobocks richly deserve an Exceptional Value Award for 2012.

Carver VTA180M Monoblock Power Amplifiers

MSRP: $7,400/pair

www.bobcarver.com

Peripherals

Analog Source             AVID Acutus Reference SP/TriPlanar/Lyra Atlas

Digital Source              dCS Paganini 4-box stack, Sooloos Control 15

Phonostage                  Audio Research REF Phono 2SE

Speakers                      GamuT S9

Cable                           Cardas Clear

Accessories                 Furutech DeMag, DeStat, Audio Desk Systeme RCM

Everything Hans-Ole Vitus makes is heavy. Really fucking heavy. Break-your-back heavy. But those who possess the strength to lift his SM-010 monoblocks out of the boxes will be rewarded with fantastic sound. That said, it’s become very popular of late, at least in the United States, to take shots at the wealthy and, in particular, at luxury goods. So if the idea of a $40k pair of amplifiers seems offensive, let fly the invective and take a pass.

While my bias leans towards vacuum-tube gear, the finest Class A solid-state amplifiers (like the recently reviewed Pass Labs XA160.5s) offer equal palpability and don’t require having to regularly forage for tubes. Heat is the only drawback to Class A units. They are power-hungry animals, but wildlife worth feeding.

Vitus gear not only feels powerful, it looks powerful just sitting on the rack. Also available with massive red-, gold-, or black-anodized front panels, our SM-010 review samples were anodized in a stunning shade of dark gray. I’d love to see more manufacturers adopt this trend. Apologies to the Oakland Raiders, but haven’t we had enough silver and black?

Beneath the SM-010’s top panel lurks a masterpiece of modern know-how—a tidy circuit layout revealing clean electrical and mechanical design. Top-grade parts are used throughout. An enormous power transformer, custom designed for Vitus, is a work of art in its own right—and not the usual toroid that exists in most other amplifiers. Individual amplifier boards, connected directly to the circuit boards to keep signal paths as short as possible, are to the left and right of the power supply.
A solitary XLR input, along with the standard IEC power connection and two speaker outputs to facilitate bi-wiring, makes it easy to integrate a pair of SM-101s into any system. These beasts can be used as 100-watt-per-channel amplifiers in Class-AB mode or 40-watts-per-channel amps in Class A mode. With every speaker, save the Magnepan 1.7s, Class A mode yields enough power for all but the most intense listening.

Flick of the Switch

The SM-010s power up in AB mode but can easily be switched into Class A via the remote control or front panel. Yes, my inner Homer Simpson loves any adjustments that can be done from the comfort of a listening chair—it really does make the evaluation process easier. When switched to Class A, the change in the amplifiers’ performance is slightly more than subtle, acting as a tube amplifier does when switching from pentode to triode mode. Unlike all the tube amplifiers I’ve auditioned that offer this function (and make a loud ker-chunk sound when altering modes), the Vitus effortlessly and silently switches between A and AB, making sonic inspections all the more interesting. And while engaging triode mode with a vacuum-tube amplifier usually bestows more midrange lubricity, it comes at the expense of bass control. The SM-010s require no such sacrifice.

Again, like a tube amplifier, the SM-010 needs a solid hour or two for the slight initial haze to dissipate. While not green in practice, if you want to experience the best it has to offer (especially in Class A mode), leave the amps on for a day before you begin critical listening. However, prepare to see a bump in your electric bill the following month!

Listen to This

On “Hear My Train A-Comin’” from Jimi Hendrix’s recent Winterland compilation, the Vitus’ deliver the virtuoso’s distorted guitar in spades and Noel Redding’s bass playing in a way I’ve never experienced. Textures in the latter blend with the distortion, the mix growling as if emanating from the band’s vintage Ampeg amplifiers. Metallica’s so-called “Black Album” offers similar revelations when cranked up. The plucked bass line in “Nothing Else Matters” flaps my pants leg as it does at a Metallica concert. All six of my GamuT woofers work strenuously and, yet, stay controlled. I’ll trade all the string quartets in the world for five minutes of this experience, and the Vitus amplifiers grant my wishes. After a full day of seriously heavy music (that, admittedly, to the disappoint of editor Bob Gendron, did not include any St. Vitus albums), these amplifiers cannot be broken. Moreover, while they got extremely warm, their sonic character did not change.

Big solid-state power normally promises stout bass response, and the SM-010s prove no exception to the rule. Yet these amplifiers’ innate ability to unveil layer after layer of musical performances melts brain cells. If you have speakers as equally revealing as the SM-010s, you’re in for a fatigue-free experience—no matter how high or low the listening level.

Indeed, classical music aficionados will relish the delicacy with which the Vitus’ render string and wind instruments. My GamuT S9s feel like big headphones when I listen to the oboes in the Netherland Wind Ensemble’s Beethoven Wind Music. For me, texture and nuance are the chief characteristics that turn listening sessions into musical events. With the SM-010s in my system, I’m still going to great lengths to listen to records I’ve heard hundreds of times to see if I can mine new aural data.

Great amplifiers also magnify differences between mediocre recordings and standout efforts. Score another victory for the SM-010s. Used extensively in TONEAudio’s Pink Floyd coverage for Issue 40, the Vitus’ exposed subtle nuances between various Dark Side of the Moon pressings as if merely presented with apples and oranges.

Whether in AB or A mode, the SM-010s exhibit dead-quiet backgrounds with zero noise when used in conjunction with the equally silent Vitus preamplifier. When mated with my ARC REF 5 and REF PHONO 2, there’s a slight bit of tube rush—but nothing from the Vitus. This makes for a dynamic presentation, and contributes to the amplifiers always sounding much bigger than you’d expect 40-watt monoblocks to sound. They actually remind me of my favorite amplifiers from the 80s—Mark Levinson ML-2s—but boast healthier depth and detail.

The SM-010s also excel at precise acceleration and deceleration, never blurring transients. Vide, Morris Pert’s lightning-fast percussion runs in “The Poke,” from Brand X’s Masques. The amps’ perfect pace separates the percussion from the rapid-fire drumming, each keeping control of its own space. Such ability to instantaneously start and stop significantly contributes to the SM-010’s non-fatiguing sound.

Other Synergies

Partnered with my reference GamuT S9s, the SM-010s are in many ways the equal of my reference Burmester, Pass Labs, and ARC amps but, nonetheless, retain their own sonic signature. While each amplifier has its own virtues and near-faultless performance, the Vitus amplifiers thrive in their ability to resolve great detail without ever becoming fatiguing—even after full-day listening sessions.

While mixing and matching, I discovered a few synergies to be unmistakably good. For example, the B&W 802 Diamonds are completely different speakers when used in concert with the SM-010s. Normally, the 802 is very revealing and, when married to an amplifier that is either harsh or forward, mirrors the amp’s presentation. With the 802s, the Vitus sounds particularly tube-like in the upper registers, replete with the slam and control you expect from a powerful solid-state amplifier.

Heard through this combination, Keith Jarrett’s Shostakovich: 24 Preludes and Fugues, Op. 87 possesses extra depth and decay, sounding more realistic than I recall—especially on the opening “Prelude & Fugue No. 1 in C Major.” While Shostakovich is traditionally a forceful composer, this piece assumes a wistful delicacy through lesser amplifiers, as Jarrett’s light touch becomes lifeless and flat. The ultimate test? Play the composition at the low volume it demands. The Vitus passes with proverbial flying colors.

B&Ws aside, the oddest albeit most interesting combination I experienced with the SM-010s occurred with the compact Penaudio Cenya speakers. Most people would not mate a $40k pair of amplifiers with a $4,000 pair of speakers, but hey, why not give it a try? The Cenyas sounded supercharged, disappearing in the room as never before, almost as if a subwoofer entered the equation.

Not Just Another Brick in the Audio Wall

Some audiophiles argue that speakers are everything to a system, while others, maintaining the garbage in/garbage out theory, believe the source the most important link in the chain. I feel every part is equally important. But I’ve also seen plenty of astonishing speakers and fantastic source components humbled when lacking proper amplification. Truth be told, I’ve heard modest speakers deliver performances I never thought possible when a standout amplifier drives them. So, at the end of the day, I’m an amplifier guy.

A pair of Vitus SM-010 amplifiers will present no compromise to your system no matter the quality of your other components. These behemoths may even inspire you to make a few improvements once you get used to their abilities. While the price is high, it’s commensurate with the level of build and sound quality. Think of the SM-010s as an ultimate audio destination—desert-island tracks optional.

Vitus Audio SM-101 Monoblocks
MSRP: $40,000/pair
Manufacturer Information: www.vitusaudio.com

Peripherals

Analog Source AVID Acutus Reference SP/SME V/Koetsu Urushi Blue

Phono Preamplifier ARC REF Phono 2

Preamplifier ARC REF 5, Burmester 011, Vitus SP-101

Digital Source dCS Paganini Stack, Sooloos Control 15

Speakers GamuT S9, Verity Amadis, B&W 802 Diamond, Magnepan 1.7

Power Running Springs Dmitri, Maxim PLCs, RSA Mongoose Cords

Cable Shunyata Aurora SP

Accessories SRA Scuttle Equipment rack, SRA Ohio XL equipment bases, Furutech DeMag, Loricraft LR-4 record cleaner

Early class D amplifiers resemble the first efforts at CD players; a great idea that wasn’t fully realized on the first iteration or two. If you’ve been around long enough to remember just how bad those first CD players sounded, you’ll probably agree that the first class D amplifiers offered up the same aural aesthetic, sounding two dimensional, somewhat shrill on the top end and fatiguing after a short period of time.

In the last year or so, class D has improved dramatically and recent efforts by Devialet (a variation on the class D concept), Audio Research and Bel Canto reveal that these amplifiers can hold their own with their more current hungry brothers.

Add Channel Islands to that list, matter of fact, put them right at the top. The latest D-500 MKII monoblocks you see here are incredibly capable. Unlike other designs the CI amplifiers utilize a custom, full-bridge module that is not available to the DIY community along with some of their own circuitry. CI owner Dusty Vawter told me that they only use the UcD modulator and Class D output section of the module. The rest is customized in house. “You need to do some serious R&D to get great sound, you can’t just stick an ICE module in a box.”

Channel Islands has built some massive power supplies to go along with these amplifiers. While small on the outside, they weigh almost 30 pounds each. Popping the top reveals large capacitor banks and heavy wiring – these amps are built to rock. However a little bit of patience is required; the D500 MKIIs sound pretty stiff out of the box, but once powered up and played for about 2-3 days, the congestion clears to a bold, dynamic sound. Vawter mentioned that the modules have some power constantly applied when in standby mode, so they only take about 10 minutes to sound their best once the initial run in has been completed. Considering that these amplifiers only draw about 13 watts of power each, I suggest leaving them on all the time.

Speaker Compatibility

Past experience with Class D amplifiers reveals they are often sensitive to speaker matching, just like a vacuum tube amplifier- some combinations can be fantastic, while others can be awful, so an audition is definitely required. We made it a point to audition the D-500 MKIIs with a wide range of speakers: The Verity Rienzis, MartinLogan Aerius and ElectroMotion, the Magnepan 1.6, 1.7 and 3.7s the new Dali P5, Harbeth P3ESRs, B&Ws 805 and 802 Diamond and of course, my reference GamuT S9s.

This comprises a fairly wide range of loads, some easy to drive, others not as much. The D-500 MKIIs turned in an excellent performance in with everything on the list except for the B&W Diamonds. Wanting to verify whether this was anomalous behavior with my speakers or something else in my reference system, installing the D500 MKIIs in another system featuring 800 Diamonds exhibited the same rolloff in the HF region, compared to all the other amplifiers at my disposal. I would suggest the owners of B&W’s Diamond series to get a thorough demo first and CI agrees – they offer a 30 day money back guarantee – less a 10% restock fee and return shipping. A small price to pay to assure system synergy.

It’s also worth mentioning that the D-500 MKIIs worked well with a wider range of speakers than any other Class D amplifier I’ve yet sampled. And they are an exceptional match with the Magnepans, which are typically power hungry. If you are considering a pair of Maggies, the CI monoblocks would be at the top of my list.

Preamplifier Compatibility

The D500 MKIIs are neutral tonally, neither adding warmth to the sound, nor forward sounding in a way that could be construed as a thin presentation. However, system synergy and compatibility is always an issue – in the view of this writer perhaps one of the most important, yet most often disregarded elements of system setup.

Marvelous results were achieved with all four of the preamplifiers on hand. (Croft 25, McIntosh C500, Burmester 011 and the Audio Research REF 5) All but the Croft were balanced preamplifiers and connected thusly. While the arguments continue to go back and forth about the value of balanced versus single ended design, I preferred the D500 MKII’s in balanced mode more – the presentation appeared a bit quieter overall. However, if you have a single ended (RCA) preamplifier, don’t shy away from these amps, you will not be disappointed.

Preferring the combination of a tube preamplifier with a solid state power amplifier to cheat the equation, if you will – getting the grip and slam of solid state with the added warmth of tubes thrown in for good measure worked well here. Neutrality is a two edged sword; some want to hear everything on a record “warts and all,” while others want hyper detail, with yet others liking a certain amount of tonal richness to the sound (that can either be described as warm, romantic or even distorted).

Biases exposed, a little bit of tonal warmth still gets my vote, as long as it doesn’t affect the pace of the music – a tough order, but it can be done. The perfect combination ended up being with the McIntosh C500 control center, a two box preamplifier that incorporates an excellent MM and MC phono stage built in, with enough inputs for everything you can imagine. Vawter encouraged me to take this direction, “We have a lot of customers that really enjoy our amps with a tube preamp.” The C500 used as a reference component at TONEAudio is hot rodded ever so slightly with a full compliment of EAT 12AX7 tubes that retains the tonal balance of this preamplifier while offering more dynamic range and a lower noise floor.

Because the D500 MK IIs possess very high gain, (32db or they can be supplied as a higher gain model featuring 38db of gain), most preamplifiers should present no problem and these amplifiers should lend themselves well to a passive preamplifier as well. When using the CI amplifiers with the ARC REF 5, the level never went past 15 on the fluorescent display to achieve maximum volume, which is very low. Even vintage preamplifiers with minimal output will have no problem driving the D500 MKIIs to maximum output.

Further Listening

The neutrality that these amplifiers exhibit makes them a great building block because they will not add to the character of other components in your system, making it easier to lock in speakers (undoubtedly the toughest component to interface with your room) and amplifier while tuning to taste, if necessary, elsewhere. Think of your amplifier and speakers as the rhythm section in a band – that essential foundation, that everything else builds upon.

Trixie Whitley’s lead vocal just leapt out of the GamuT’s on the first track, “Love Lives” from Black Dub’s self titled album, with Daniel Lanois’ backing vocals floating from left to right across the soundstage, somewhat diminished in the distance. An abrupt switch to a few trippier selections from Jean-Michel Jarre further confirmed the three-dimensionality delivered by the D500 MKIIs. Equinoxe never sounded better, and Zoolook offered up stirring bass lines.

Following this quest for bass a little further, Ursula 1000s disc, Mystics proved that the D500 MKIIs could not only deliver a large soundfield, but they could deliver deep bass with power and control. Pushing the G9’s to rave music was effortless and even at deafening volume (It felt like being back at the MICS festival in Monaco, minus the dancing girls) these amplifiers kept a lock on the pace, offering up wall shaking beats with no shrinkage of soundstage in either dimension. And of course, all the Yello tracks rattled the room.

This grand soundfield increased as I switched to vinyl – after a few of my favorite LP’s I forgot that I was listening to the tiny boxes on top of the $60,000 pair of Bumester 911 power amplifiers. Again, Vawter encouraged me to compare the D500 MKIIs to the best amplifiers I could get my hands on and they proved formidable. When listening through the GamuT S9s there was still one hurdle between the Burmester, ARC and Pass Labs amplifiers at my disposal in terms of removing the last bit of grain, or palpability, but I can’t remember ever hearing a pair of $5,000 amplifiers sounding anywhere near this good. It was only when I returned to the big bucks amps that I noticed a difference.

Making the power hungry Magnepan 1.7’s part of the equation was equally splendid. One of the biggest dilemmas with the Magnepan speakers is that while they are highly revealing for an inexpensive speaker, they require a lot of power to really light up the listening room. The D500 MKIIs took control of the Magnepans as well as some of the world’s best amplifiers have- I can’t think of an amplifier I would suggest more highly for someone looking to build a high performance system around the 1.7’s (or the 3.7’s for that matter) at a reasonable cost.

The absence of a sound

The Channel Islands D500 MKII amplifiers sounded great and made no missteps while in our care. We will be adding them to our reference fleet of amplifiers, so you will be hearing more about them in the months to come. I feel compelled to give these amplifiers one of our Exceptional Value Awards for 2011 as well – they represent tremendous performance and build quality. A well thought out product in every way.

The Channel Islands D500 MKII monoblocks
$5,000/pair

www.ciaudio.com

Peripherals

Preamplifier McIntosh C500

Analog Source AVID Acutus Reference SP w/SME V and Koetsu Usushi Blue

Phono Stage ARC REF Phono 2

Speakers Gamut S9

Power Running Springs Maxim and Dmitri power line conditioners

Merely mentioning that you still listen to vinyl records in casual conversation amongst non-audiophiles almost always invokes a raised eyebrow. And if you try to explain the thrill of vacuum tubes, people that don’t give you a dog-like stare will surely move you to the penalty box. But as vacuum tube fans know, current designs continue to advance like the Energizer bunny, with the best examples light years ahead of the humble beginning of the Williamson circuit from the 1940s. In 1955, the Heathkit version of the original circuit claimed to have “performance far beyond the finest speaker systems available.”  Much has improved since then.

Hailing from Germany, the Octave MRE 130 monoblocks look straightforward in terms of aesthetics. But they’ve also combined a few unique features, along with meticulous attention to detail, to create a pair of power amplifiers that sit at the top of their class. The standard MRE 130 monos run $16,000 per pair, and thanks to external power supply modules ($7,500 additional per pair), allow for the option of taking their stunning performance even further.

The most distinctive aspect of these amplifiers is the substantial redesign of the classic pentode amplifier circuit. The first part of the Octave approach is its power management system, which not only provides a soft start for the tubes, but also furnishes a separate supply that is optimized for the input stage—as well as another for the output stage and a third section that takes care of the additional current requirements of the pentode circuit. In addition, an electronic protection circuit protects the amplifier from damage, should tube failure occur while remaining audibly transparent.

While Octave has only been distributed in the United States for a few years, the company began in 1968 when founder Andreas Hoffman’s father began a transformer-winding factory in Germany. Hoffman started building solid-state amplifiers in 1975 and turned his attention to tubes in 1977. In the years that followed, his products won numerous awards in Europe and Asia.

The MR 130 amplifiers are rated at 100 watts per channel into an 8-ohm load and 130 per channel into 4 ohms. Available in silver or black, the MR 130s are substantial at 46 pounds (22.7kg) each, but not so heavy that they need more than one person to lift.

Setup

Removing the tube cage reveals a complement of two 12AU7s (ECC82C) and a 6C5 as driver tubes, with a quartet of 6550s for the output stage. They can also be configured with KT88s. The review pair came with KT88s installed, and Octave was thoughtful by including two spare power tubes. The company should also be praised for producing one of the most comprehensive and well-written manuals in the industry. It offers background on the design, a thorough explanation of how to properly bias the tubes, and finally, for the technically inclined, measurements.  Hoffman has indicated that future versions of the MRE 130 have been slightly modified to ship with a 6SN7 in the place of the 6C5, to make it easier to find replacments, but assured me that there is no change in sound.

Once the tubes are installed in their respective sockets, the output tubes need to have proper bias set. Five LEDs indicate bias status. A middle green LED indicates correct bias, while a yellow one to the left of center glows with an underbias situation and a yellow one to the right indicates overbias. An orange LED all the way on the far left is used when installing a fresh set of tubes. Finally, a red LED on the maximum far right position only lights when a tube is defective.

The remainder of the setup is straightforward, with two pairs of easily accessible speaker binding posts and a pair of RCA and XLR input sockets. Input type is selected via a switch, and the inputs can be shorted as well, so you can change cables without causing amplifier or speaker damage. XLR connectors are offered, but the amplifier is not fully balanced, as Hoffman doesn’t feel that it’s a superior way to design a tube amplifier.

Although the manual states that output tubes can take “up to 300 hours to sound their best,” my review samples had just come from the Rocky Mountain Audio Fest, where they had about a week on the clock. I did not hear a change in amplifiers’ sound character during the test period, other than that of initial warm-up. The MRE 130s require about 45 minutes to sound their best.

It’s also worth mentioning that an output tube failed during the course of this review, and while such an episode may have caused drama with other amplifiers, the MRE 130 simply went quiet. The corresponding red LED lit up to indicate the defective tube. Once the latter was replaced, the MRE 130 went back to performing flawlessly.

Listening Impressions

Beginning with a handful of audiophile classics, I was instantly struck by the soundstage depth and fine detail offered by the MR130s. The LP of the Fleet Foxes’ debut encapsulated such characteristics, keeping the band members’ harmonies wonderfully separated. And the title track from the new Fleet Foxes record, Helplessness Blues (reviewed this issue), proved quite a treat as well. The heavily layered vocals were easy to pluck from the main musical line, as they floated above and in front of the big bass drum in the background.

John Fogerty’s version of “I Put a Spell on You” from Creedence Clearwater Revival’s self-titled album (45RPM Analogue Productions version) proved equally captivating. Shortly thereafter, the band’s “Suzie Q” equated to retro treat, with the lead guitar distinctly defined in the far left channel, full of glorious distortion as Fogerty chimed in and out of the right channel. Yet the bass guitar sounded diffuse, hanging back behind the performers. It was as if bassist Stu Cook was off playing in another room.

While most tube amplifiers impart a glorious sense of pace and a generous measure of air, they usually falter in the area of bass control. But the MRE 130s did not fall victim to the common problem that plagues all but the world’s best tube amplifiers— proof that Hoffman’s power-supply design is highly successful. The funky bass lines in George Michael’s “Hard Day” from Faith arrived with just the right amount of weight and grip, and without losing control. Keep in mind that this song usually overwhelms most tube amplifiers and ends up boomy.

I was equally impressed with the deep bass performance of the MRE 130s when grooving to George Clinton’s “Why Should I Dog You Out?” from The Cinderella Theory. If you have speakers capable of delivering major low-frequency extension, the MRE 130s will step up to the plate. Depth and dimension were definite specialties of the MRE 130s even if they weren’t the equivalent of my Burmester 911 mk.3s. But the Octaves were about to make some big performance gains.

Increasing Performance: Step One

Users not interested in experimenting with different tube configurations will enjoy the MRE 130s as outfitted at the factory. However, if you are a maniacal tube enthusiast that always searches for more performance, rest assured that more is on tap. Towards the end of the review period, the new KT120 power tubes were released. And while this model isn’t a plug-in replacement for every amplifier that utilizes 6550 or KT88 tubes, Hoffman assured me that the MRE 130s’ power supply was up to the task of this particular tube’s increased current demands.

Hoffman also claims that, without redesigning the amplifier, it really won’t produce much more power than with the stock KT88 tubes. Yet, with the KT120s installed, the sound quality tremendously improved on both ends of the frequency spectrum. Bass became deeper and tighter, with even better control than before. The MRE 130s already exhibited some of the most controlled bass I’ve ever heard from a tube amplifier, and with the KT120s, they offer even more grunt.

At the other end of the spectrum, more air circulated around cymbals than before.  Heading back to the CCR catalog, the high hat cymbals seemed to float better while the overall sound achieved a heightened level of refinement. Acoustic instruments became fleshed out with more body; the more complex sounds of the violin and piano took another step towards reality. Originally recorded to two-track 30 i.p.s. tape, Liz Story’s Steinway on her Solid Colors LP suspiciously sounded like the one in my living room.  The amplifiers did an excellent job of letting me just forget about the gear and get lost in the musical presentation.

While the MRE 130s came with a pair of JJ ECC82s (12AU7) installed in each unit, swapping them out for the new Pvane 12AU7s from Shunuang yielded more delicacy. Substituting your favorite NOS tube may change the tonal character of the amplifier, but the new Pvane tubes did not alter tonality. They simply dropped the noise floor of an already very quiet tube amplifier even further, and peeled off a layer of grain that I didn’t previously know existed.  If you do nothing else to your MRE 130s, I highly suggest making this small change.

Step Two: Adding the Big Black Boxes

After becoming thoroughly familiar with the MRE 130s in their stock form and then again with upgraded tubes, another big performance jump came via the Super Black Box, which incidentally, is silver. While a pair of Super Black Boxes add $7,500 to the MRE 130s’ price tag, the improvement is major—and well worth it. As you might suspect from such a substantial upgrade, the soundstage immediately became larger in all three directions, the upper register had more clarity, and the bass possessed even more heft and control.

Whereas Naim gives you the opportunity to add a completely different power supply, the Octave Super Black Box is a giant capacitor bank tethered to each amplifier by a massive power cord and connector. Once powered up, the Super Black Box has a blue status indicator—just like the power amplifier. Should you feel the need to disconnect them, a yellow LED glows for approximately two seconds, indicating the discharge. Hence, you will not be exposed to any harmful voltage when unplugging them.

Digging through deep tracks to locate old-school synthesized bass, I dusted off Edgar Winter’s Jasmine Nightdreams. The second cut, “Little Brother,” has a fairly loose and whumpy albeit powerful bass line that was much more agreeable with the Super Black Boxes in place. The song lost some looseness but not the character of the bass.  I discovered the same effect when playing “Word Up!” from Korn’s Greatest Hits, Vol.1. The driving bass line attained more authority and punch than before, an experience that led me to revisit most of the initial tracks I used to determine the MRE 130s’ character. A definite transformation.

Still, the improvements afforded by the Super Black Box went beyond bass performance. The three-dimensional aspect of the presentation increased to the point that I felt as if I were listening to surround sound. Kraftwerk’s Tour de France took on an uncanny sense of depth that normally requires an analog source to achieve. I found myself listening start-to-finish to several albums in the digital format that I normally experience one or two tracks at a time before moving on. The MRE 130s’ resolution healthily expanded, as did the jump in dynamic range.

Hoffman also told me that one of the side benefits of additional power-supply capacity lowered the amplifier’s output impedance, which accounts for its spectacular bass performance. Such extra capacity also gives the MRE 130s’ the ability to more easily drive difficult loads. I had no problem driving my MartinLogan CLX speakers or the Magnepan 1.6s, each notoriously tough to drive with tubes. Without the Super Black Boxes in place, the MRE 130s ran out of juice with the Magnepans and rolled off the highs with the CLXs. This upgrade is a must if you plan on using these amplifiers with either speaker.

Before adding the upgraded tubes and Super Black Box, the MRE 130s took a back seat to my Burmester 911 Mk. 3 monoblocks in terms of imaging and delicacy. But, after I made the changes, the Octave units held their own in these areas when played within their limits—very impressive for a pair of amplifiers that cost one-third as much as the Burmester gear.

Conclusion

While I can’t imagine using the Octave MRE 130s without the Super Black Boxes now that I’ve had the experience, they are fantastic amplifiers without the add-ons, and Octave is to be commended for giving the end user the opportunity to work their way up to a statement product.

The Octave MRE 130 monoblocks should satisfy all but the most power-hungry systems. If 130 watts per channel is not enough, Octave also produces floor-standing Jubilee monoblocks, which we will audition in the near future. If you’ve always wanted the benefits of tube amplification without any of the drawbacks, these amplifiers are for you.

Octave MRE 130 Monoblock Amplifiers

MSRP: $16,000/pair; Super Black Box: $7,500/pair

Manufacturer Information:

www.octave.de

Peripherals

Analog Source                        AVID Acutus Reference SP w/SME V and Koetsu Urushi Blue

Digital Source                        dCS Paganini (4 box stack), Sooloos Control 15

Phono Preamplifier            ARC REF Phono 2, Octave Phono Module

Preamplifier                        Burmester 011, McIntosh C500

Speakers                        GamuT S9, MartinLogan CLX, Magnepan 1.6, B&W 805D

Cable                                    Cardas Clear

Power                                    Running Springs Maxim and Dmitri power conditioners, RSA and Shunyata power cords

Accessories                        Furutech DeMag, SRA Ohio Class XL+² equipment platforms, Loricraft PRC -2 record cleaner