Pass Labs XA160.8 Monoblocks

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



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

Balanced Audio Technology VK-655SE

The only promise that BAT’s VK-655SE does not fulfill is the company’s claim that it has enough energy storage to “to lift most speakers over one meter off the ground.” Even at earsplitting levels, neither the 610-pound GamuT S9 nor the 253-pound Dynaudio Evidence Platinum speakers move ever so slightly off the ground.

What the VK-655SE does deliver is musical accuracy, exquisite tonality and bass control. With 1,800 joules of power available, the $16,500 VK-655SE controls the lower half of the frequency spectrum in a way that precious few amplifiers can muster at any price. For the non-electrical engineers in the audience, a heart defibrillator uses between 200 and 400 joules at its maximum setting, so while the VK-655SE won’t lift your speakers off the ground, if you connect your speaker cables to your chest and crank it up, it will probably lift you a meter off the ground. Maybe that’s what they meant.

Speaking of weight, the VK-655SE weighs 120 pounds, so make sure your back and whatever stand you plan to place it on can withstand that much heft. Popping the lid reveals a pair of monstrous heat sinks, power transformers and capacitor banks. The VK-655 is available in all black (as shown here) or with a black-and-silver aluminum faceplate. In the future, BAT will also offer all silver, so if that is the aesthetic you desire, its on the way. Fully intended for use in an all-BAT system, the VK-655SE offers only balanced XLR inputs—though we found that the VK-655SE works equally well with Pass, ARC, Nagra, Simaudio and Robert Koda preamplifiers; all were used in a fully balanced configuration.

Let’s Roll

The VK-655SE is special straight out of the packing carton. Taking the hot-rodders credo, “If you want it to run hard, you have to break it in hard,” I immediately reach for Metallica’s album Kill ’Em All and play “No Remorse” at near-Armageddon levels. Even during a brief stint of driving the Dynaudios to almost 120 dB peaks, the BAT doesn’t strain whatsoever, with the raw power of Metallica thoroughly communicated. While I can’t imagine needing more power, you can turn the VK-655SE into a monoblock amplifier and get a bit more, going from 600 watts per channel into a 4-ohm load to 700 watts per channel. (The VK-655SE produces 300 watts per channel into an 8-ohm load as a stereo amp, and 400 watts as a monoblock.)

For those scoffing at the idea of paying twice as much for only 100 more watts per channel should remember that higher fidelity means gaining control, not just getting louder. This is because doing so doubles the current output, giving the monoblocks the ability to control difficult loads more effortlessly. Having twice as much power on tap will make those monos run even more effortlessly than running them in a stereo configuration, translating into greater dynamic range and an even quieter background – 6db according to BAT. I notice a similar effect going from a single Burmester 911 MK3 power amplifier to a pair of 911 monos. It is not subtle. I’ll stick my neck out and suggest a pair of mono VK-655SEs will achieve the same results.

Experience with BAT’s past products featuring the Super Pak upgrade (the company’s own variety of oil-filled capacitors to help facilitate all this power storage) showed that these components take a while to sound their absolute best—anywhere from two to 500 hours. The higher current flow of large power amplifiers makes the process a somewhat speedier one; the preamplifiers seem to take longer.

Slightly edgy at initial turn-on, the VK-655SE sounds more open, natural and relaxed in the upper register after about 48 hours of constant play, with a subtle smoothing as the hours rack up, but not as dramatic as the change during the first couple days. For the crabby audiophiles in the crowd who do not believe in component break-in, I highly suggest borrowing a pair of identical amplifiers, running one for a few hundred hours while you leave one in the box for that period of time and then compare the two. There is an unmistakable difference between the amplifier with hours on the clock and the one left in the box.

BAT’s Geoff Poore makes it a point to stress that they strive for “dynamic linearity” in their designs. A big part of this comes from their eliminating negative feedback in combination with an unlimited, unregulated power supply – adding to the jump factor that BAT amplifiers are famous for. It’s also one of the main reasons this huge amplifier exhibits the dexterity of a much smaller amplifier. Poore reminds me that “using only two gain stages in the VK-655SE eliminates coupling effects between multiple gain stages, further reducing the amount of image smear and degradation that comes with a more complex design.”

Where some power amplifier manufacturers claim a dual-mono design, BAT takes it to the extreme. In addition to separate power transformers and power supplies for each channel, the VK-655SE even uses separate power cords and receptacles for each channel! Should you have access to dedicated power lines, I suggest trying separate power lines on separate circuits for each channel. My curiosity with the VK-655SE is satisfied plugging each channel into separate 20-amp circuits. Of course, you don’t need two power lines for the VK-655SE, but with two separate mains fueling the fire at ear-splitting levels, the amp exhibits even more ease. About 95% of the time, you’ll never notice it, but if you really like it loud, go for separate AC circuits to power each half of your VK-655SE.

A Quick Comparison

If you believe all amplifiers have the same sound, stop reading now. Though the world’s top solid-state amplifiers are starting to sound more similar than disparate, differences in sonic character still exist. Side-by-side comparisons to a few of our regular amps reveal the BAT to excel in speed, dynamics and bass weight. The Burmester and Pass amplifiers in our stable are slightly warmer tonally, while the big Simaudio MOON 880M monos sound as natural as the BAT, but more bottomless in power capability—albeit at a higher price than a pair of VK-655SEs. It’s almost like comparing an Audi to a BMW or a Mercedes; all are excellent, though they go about delivering the goods in a slightly different way.

None of the speakers we have on hand present a challenging load to the mighty BAT. The current-hungry Magnepans and even our vintage Acoustat 2+2s, which have only an 82 dB sensitivity rating and are not much more than giant capacitors placed across the speaker terminals, do not diminish the amp’s performance in the least. Where some amplifiers can be speaker-dependent and struggle at times, the VK-655SE effortlessly powers every speaker we have on hand with ease.

Part of the neutral sound quality of the VK-655SE can be attributed to its use of all N-channel MOSFET output transistors. The N-channel MOSFET has a higher electron mobility, which makes amplifiers with them appear to have more transient speed than amps with mixed devices. Cursory research on the N-channel MOSFET implies that the N-channel device also has a wider range of operation where it acts like a triode tube—another great thing to have in a power amplifier. Techie bits aside, this amp succeeds brilliantly, especially for $16,500.

Bigger Is, Well, Bigger!

Some arguments in audiophile circles—about the quality of the first watt and that, because of their inherent complexity, higher-powered amplifiers are not as pure as low-power amplifiers in design and thus sound—don’t always hold true. Those arguments certainly don’t hold true in the case of this amplifier. While I’ve heard excellent examples of both low- and high-powered amps, I still tend to prefer the effortlessness of a high-powered one, even at low volumes. The VK-655SE takes a novel approach, featuring no negative feedback and only two gain stages in the entire circuit. In the same way that some large speakers manage to disappear in your listening room like a mini monitor, the VK-655SE has the sheer might of a large amplifier and the nuance of a small power amplifier.

Listening to acoustic instruments highlights the character of the VK-655SE. Its enormous power reserves might not be noticed with less-demanding fare, but the instant a drumstick hits a cymbal or the string of a standup bass is plucked with force, the boundless reserves of this amplifier deliver the dynamic swing required to convince your auditory system that perhaps you’re not listening to recorded music at all.

This is equally true when reproducing a vocalist with a wide range. Whether it’s your favorite opera or Prince, the VK-655SE’s instant delivery comes through free from the stress associated with lesser amplifiers unable to keep up—and this ability is too often overlooked when jumping on the low-power bandwagon. Simple as it might seem, a big, well-executed amplifier just sounds bigger and has a lack of restraint that further contributes to its overall neutral character.

There was nothing that the VK-655SE couldn’t handle effortlessly during this review. In the realm of the reference speakers at my disposal—all with sensitivity ratings of 87 to 90 dB—I can’t imagine ever needing more power than this amplifier delivers. BAT gear is known for its fantastic build quality and excellent secondary-market value, so for an amp at this size and price, I also can’t imagine ever needing another one once you’ve stepped up to the VK-655SE. Unless of course you need a second one.

BAT VK-655SE power amplifier

MSRP: $16,500


Analog Source AVID Acutus Reference SP turntable    TriPlanar tonearm    Lyra Atlas cartridge
Phonostage ARC REF Phono 2SE
Preamplifiers Robert Koda K-10    ARC REF5 SE    Pass Labs Xs
Digital Source dCS Pagaini Stack    Simaudio MOON 650D
Cable Cardas Clear
Power IsoTek Super Titan

DALI Rubicon 2 Speakers

Toward the end of “Master Song,” the second track on Leonard Cohen’s breakout 1967 album, Cohen’s pursing lips sound eerily present through the 1.1-inch soft dome tweeter of DALI’s two-way Rubicon 2 speakers. This remarkable tweeter reveals all the imperfections and detailed character of this vinyl pressing. Similarly, on “The Stranger Song,” the speakers’ 6.5-inch drivers pick up several mic pops—as Cohen hits phrases like “plays for shelter” and “holy game of poker”—doing so with jarring airiness, a result of the DALI speakers portraying this rough but rich recording with loads of nuance and clarity.

It’s details like these that help immediately illustrate speaker quality. And DALI—an acronym for Danish Audiophile Loudspeaker Industries—has gained a reputation for producing high-quality, high-fidelity speakers at relatively reasonable (even mid-fi) prices. Of course, at $2,995 per pair, the Rubicon 2s are far from budget speakers, but they do display characteristics you’d sooner expect from much larger and costlier models. For their size and price, the level of fidelity these speakers deliver is astounding.

Setup and Specs

Measuring about 14 inches tall, 7.5 inches wide, and 13 inches deep, the Rubicon 2s are appropriate for placement on a shelf or bookshelf, tabletop/desktop or on stands. For this review, I try placing the speakers at the forward corners of my 21-inch-tall Salamander Synergy hi-fi rack and on my 35-inch-tall speaker stands. I find that the stand placement gives the speakers the necessary height to cast a deep enough soundstage to reach the listening position about 9 feet from the speakers (though stands 28 to 30 inches tall would have placed the tweeters right at ear level, so I raise my listening seat to help make up the difference). The speakers are ported out the back, so they should be placed at least a foot or so from the back wall. Placing the speakers about 2 feet from the wall and about 6.5 feet apart (with only very slight toe-in) presents the most satisfying soundstage for this reviewer.

Beyond the time required to find the optimum placement, setting up the speakers is an absolute breeze. The gold-plated, plastic-encased terminals are big and sturdy and make it abundantly easy to connect the speaker wire. Bi-amping is not an option, but DALI says that amps with an output of as little as 40 watts will do the job. The Simaudio Moon 600i integrated amp I’m currently using as a reference really makes these speakers sing, but it is pumping 250 watts into the speakers’ 4-ohm impedance load. DALI’s specs say the speakers deliver a frequency range from 50 Hz to 26 kHz, with a sensitivity of 87 dB and the crossover set at 3,100 Hz.

The cabinet of the Rubicon 2s is MDF and available in one of four finishes: black or white in high-gloss lacquer, or veneers of rosso or walnut (walnut shown). At about 18 pounds each, the speakers are pretty hefty for stand/shelf models, which contributes to the sense that these are high-quality speakers with refined fit and finish.

Back to the Music

London Calling is one of my favorite all-time albums and is way more nuanced and better produced than most people realize (especially since it’s largely considered a punk album—but it’s so much more than that). As a result, it’s a great test record for speakers, many of which struggle to deliver the 180-gram vinyl version’s full depth and richness. During the title track, Topper Headon’s hi-hat hits are crisp and bright through the Rubicon 2s, which highlight Headon’s complex rhythms and fast stick work. In general, these speakers lean toward the bright side of the spectrum, though they are not lacking in warmth. Through lesser speakers with less-capable tweeters, the electric guitar on this track can sound gritty, even muddy, but the Rubicon 2s parse through the grit, revealing an almost jazzy tone to this punk riff.

The Rubison 2s deliver “Sacrafice,” the fourth track on the Roots’ 2002 album Phrenology, with more low-end bump than I’d expect from speakers this size. When the kick drum and bass guitar hit, I’m surprised to feel my chest rumble, which leads me to believe that the speakers’ 50 Hz low-end spec is not an exaggeration. It doesn’t rattle the walls of my apartment or anything, but it’s plenty of bass response and quite the feat for 6.5-inch driver cones.

Further illustrating the low-frequency capabilities of these speakers, the opening track of Wilco’s Whole Love on vinyl is an almost techno-sounding amalgamation of a strong beat with orchestral strings, electric guitar, amplified piano, and all sorts of trippy effects and tiny electronica noises bouncing around the soundstage. The little DALI speakers capture this big and complex recording with laudable deftness, casting a broad soundstage that extends well into the listening area and is ripe with detail and a well-sorted-out multitude of instruments. The snare hits as the song crescendos toward the end of the track are fast and realistic (coming from someone who is a drummer and has seen Wilco live), and as the bass builds, the drivers deliver a really solid LF response—there’s a lot of air coming from these speakers.

Acoustically Speaking

I like using John Gorka’s Gypsy Life on Blu-ray as a reference, because it lets you see the physical location of the musicians and gives you the option to listen to the 24-bit/96-kHz stereo mix. Delivering this audio-video experience is my extremely capable Oppo BDP-105 universal disc player. During the title track (my favorite on the disc), the DALI drivers convey Gorka’s baritone vocals with loads of depth and clarity. The speakers give a notably accurate portrayal of the soundstage, with the fretless electric bass, mandolin, Gorka’s vocals and acoustic guitar, and female backup vocals placed from left to right, just as they are in the recording studio. The bassist uses an EBow (a little battery-powered device that mimics a bowed instrument), which gives the bass a really cool ambient vibe that the Rubicon 2s portray with plenty of air and vibrato; the mandolin is delicate but still abundantly present; and the female vocals are wonderfully subdued as they complement Gorka’s deeper voice. The DALIs perfectly place all these elements in the mix, giving the track an extremely lifelike feel.

I will say that these speakers don’t quite push the mix as far out as I’m used to with the larger Stirling SB-88s and the floorstanding ELAC FS249s that I’ve been using as reference speakers. By comparison, the Rubicon 2s lack the more substantial physical depth and three-dimensionality of the larger speakers. But compared to the other shelf/stand speakers and monitors I’ve demoed, the DALIs do present considerable spatial presence.

A CD of a live recording of Shostakovich’s String Quarter in C minor (with Leonard Bernstein at the helm of the New York Philharmonic) sounds quite engaging through the Rubicon 2s. The frantic violin pulls dominate the left side of the soundstage, with the cello and contrabass responding at the right. The simultaneous melodies are captivating and displayed well out in front of the speakers, though perhaps not pushed all the way out to the listener or as far beyond the peripheral boundaries as larger speakers might. That being said, the Rubicon 2s do deliver extraordinary accuracy, depth, and richness for speakers of this size.

A Worthy Contender

There are plenty of options for high-quality stand/shelf speakers or monitors in the $3,000 range—from Bower Wilkins, Sonus faber, Harbeth, and numerous others—and the $2,995 DALI Rubicon 2s certainly hold their own. Their most praise-worthy characteristics are their accuracy, clarity, and broad frequency response, with an especially notable bass response for their size.

The tone of the Rubicon 2s tends to be a little bright with higher frequencies, though the mid and bass regions do come through with a subtle amount of warmth that lends the speakers really nice balance. Placed in a moderately sized room and paired with the right stands and a decent amount of power, these speakers can really sing and fill a reasonable amount of space with extremely satisfying music.

DALI Rubicon 2 Speakers

$2,995 (manufacturer) (U.S. distributor)

KEF LS-50 Speakers – Blue and White

We love the KEF LS-50 and after almost two years, three of the TONE staff use them as their small speaker reference, so we are still enamored. With so much essence of the KEF Blade in such a small package, these speakers offer scary good imaging and coherence. In a small to medium sized room with great ancilliaries, you might even be fooled into thinking you are listening to a much larger pair of KEF speakers.

Much as we’d like to tell you the super cool white and blue LS-50s you see here sound even better than the black and copper ones, they don’t. But they do offer a different, perhaps even more modern aesthetic than the original model. Perhaps KEF will take note of this and offer further customization on the LS-50 and other models. This kind of thing goes a long way towards getting speakers in the home environment. Well played.

Blue and White KEF LS-50s


Madison Fielding Flagstone PlanterSpeakers

Water and speakers don’t usually mix well. But when your speakers double as planters, you have to water them, if you don’t want the foliage contained therein to whither and die. Like most planters, the Flagstone PlanterSpeakers—which come in three sizes, each containing a three-way weatherproof loudspeaker—feature a drain at the bottom for water runoff. The speakers are passive, so power is required—and their performance with the Audio Research GS series amp and preamp and Gryphon DAC proves seductive.

After some initial listening to “Big Log” from Robert Plant’s Principle of Moments, I subject the Flagstones to about 100 hours of Lou Reed’s Metal Machine Music on the back porch, via the vintage Harman/Kardon 730 receiver from the “Old School” column in the previous issue of TONE. This experience reinforces that these are high-quality outdoor speakers—not those rock-shaped speakers you might have seen in recent years. A great vintage receiver might be a good place to start, but I’d suggest a better-quality source to get the most out of the Flagstones.

With a 10-inch downward-firing woofer and a front panel, of sorts, with a 4-inch Audax midrange and 1-inch dome tweeter, these speakers are certainly well equipped. Outdoor placement helps fight room effects, so in some respects the Flagstones are easier to set up than speakers in your living room. Of course, ultimate placement of the speakers will be dependent upon whether or not you want a more traditional stereo soundstage and listening spot in your outdoor area. Not limited to the speakers you see here, there are a wide range of sizes and shapes available, so check their website for something that will blend with your décor – and there are some new configurations on the way.

Positioning the speakers for rear firing, about 5 feet from any outdoor walls, creates a more diffuse area-filling presentation. This minimizes the precision of the soundstage that you might be used to from listening in your living room, but it bathes your outdoor listening space in music; it also requires more amplifier power to deliver a sufficient sound-pressure level. A forward-firing orientation requires less power, offering a more focused stereo image, though this arrangement doesn’t produce the best sound at a party—unless maybe it’s an audiophile party where everyone is competing for the sweet spot!

The Flagstones feature an 89 dB sensitivity rating; yet, compared to a few other speakers currently in the TONEAudio studio with a similar rating, they produce a couple decibels less sound output, according to the sound-level meter on my iPhone 6. If you only require modest yet high-quality patio sound, 25 wpc of tube power works wonderfully. However, if you’re planning on using the speakers regularly in party mode, Madison Fielding suggests at least 100 wpc, with a maximum of 500 wpc. Art Powers Jr., one of the company principles mentions that “under driving the speakers is the biggest problem they have with the speakers out in the field.”

The Flagstones possess a wide dynamic range and excellent coherence throughout, making them a true audiophile speaker in every respect (aside from the fact that they’re disguised as outdoor décor). Recent dinner guests particularly enjoyed the combination of the Flagstones with Tidal music streaming, allowing everyone to take turns streaming their favorite tunes from the comfort of the patio furniture. The Flagstones effortlessly handle every kind of music, from female vocals to rock, and those 10-inch woofers prove convincing when the party groove shifts to serious hip-hop tracks. The woofers even convince the neighbors on both sides of our fence to join the party—a good sign.

At $3,495 per pair, the Flagstones aren’t a casual purchase for your backyard, and the only negative aspect to having such great speakers out back is the fear that someone will hop the fence and make off with them when you aren’t home. A cursory call to my insurance agent suggests that, if you purchase a pair (or two), to make sure your homeowner’s insurance covers them. You may need to get an additional rider—or at least send your insurance provider a photo of the speakers and copy of your sales receipt. But as long as they’re in your yard, it’s happy listening.   – Jeff Dorgay

Madison Fielding Flagstone PlanterSpeakers

$3,495 per pair

Audible Illusions Modulus 2 Preamplifier

In the early ‘80s a new audio company named Audible Illusions burst on the scene with a single product, a dual mono preamplifier for about $300. It got a little bit of press and no one paid a huge amount of attention to AI until 1985 when their Modulus preamplifier debuted. It had dual volume controls on the front and took care to minimize the use of switching in the signal path along with careful circuit design to present a $595 preamplifier that posed some competition for the big bucks gear of the day.

The Modulus 2D, pictured here was the ultimate realization of this circuit and was made between 1988 and 1991 before AI moved on to their model 3 preamplifier which achieved international acclaim. Using just four 6DJ8/6922 tubes, two for the linestage and two for the built in phono section, the Modulus 2D was one of the best values in high end audio for quite some time. I owned one from 1989 until 2003 where it was still chugging along in my second system quite nicely.

Though it had no fancy stepped attenuator, remote control or outboard power supply, (it had a fixed AC cord as well) the 2D sounded fantastic and in the day was the closest thing to a giant killer I had ever heard at that point. The dual volume controls were a bit of a pain and the high level inputs were limited, but it really sounded great!

This preamp had fantastic imaging and if you sprung for a fairly expensive set of 6922s it would really sing. They still do – if you happen to be an Audible Illusions user, call Kevin Deal at Upscale Audio and he’ll take good care of you.

With the top cover removed, you can see that the 2D features a simple circuit using some of the best parts of the day. Though AI had a few service issues, these preamplifiers were workhorses; many of them are still in service today. To make sure I was not just waxing poetic, I managed to pick one up on EBay for $450, which seems to be the going rate and give it a good listen to refresh my memory.

Even in context of todays components, the 2D still delivers an impressive performance. I would still suggest a Modulus 2D today; dig out your soldering iron, upgrade a few caps, install some premium NOS tubes and you’re on the way. This is a premier preamplifier on a tight budget and remains a budget legend.  -Jeff Dorgay

Conrad-Johnson PV-1 Preamplifier

The audio world is sometimes wacky indeed. In the first issue of TONE-Audio, this column featured my first real high-end preamplifier, the Hafler DH-101. Always the packrat, I recently found a box with a bunch of old receipts, for you guessed it, hi-fi gear. As it turns out, before I got my hands on a Conrad-Johnson PV-2, I actually owned a PV-1, Conrad-Johnson’s first preamplifier. To be historically correct, this preamplifier was first introduced as the Conrad Johnson Preamplifier in 1977 and then a bit later renamed the PV-1.

I bought mine in the fall of 1978, along with my neighbor Tony, and our mutual friend Jon, who was working for the local CJ dealer. What are the chances of three guys living within two blocks of each other all having a PV-1? Actually Jon bought his a bit earlier, convincing Tony and I that we needed one too. Already, the upgrade bug had bit! I ended up having the PV-1 for about a year before trading up to the new PV-2, but Tony hung on to his for a long time…

Working on my review for the flagship CJ preamp, the ACT2 (soon to be the ACT2/ series2), why not revisit the beginning of the gene pool? A quick check on EBay revealed that PV-1s were selling for about $400.

A quick call to Jon, now at Ultra Fidelis in Milwaukee, Wisconsin proved interesting and odd. “Wow, you are in luck; Tony still has his and he finally wants to trade up. I’ll box it up and send it your way!”  Back then, I had lent Tony my box to ship his PV-1 back to CJ for repairs and by the time I thought of getting it back, I already had a PV-2. In the old days we weren’t so mental about OBM.

His PV-1 arrived on my doorstep a few days later, with everything in good visual order. As strange as it is to get a one owner PV-1 over 30 years later, from the guy that used to live down the street, the plot thickens. When it arrived, it was not only in the original packaging, it was in MY original packaging! The world of high end audio is indeed wacky.

I immediately put it in a system and fired it up! A few minutes later, I was listening to vintage Conrad – Johnson sound; definitely a much warmer tonality than my ACT 2, but engaging, as all CJ components are. That this preamplifier survived all these years with no more than a tube change or two is a solid testament to Lew Johnson and Bill Conrad’s build quality. And a wonderful memory.

-Jeff Dorgay