While Audio by Van Alstine (AVA) may be a new name for many, there’s a good chance you are at least peripherally familiar with Frank Van Alstine’s work. Out of his shop in Minnesota, he spent years developing modifications and upgrades for Dynaco and Hafler equipment—and those kits are still available. For customers wishing to get hands-on with their stereo, the upgrade kits are rumored to take an already-great piece of classic equipment to an entirely new level. For those with the skills and time, these kits can provide their owners some fantastic sound at very reasonable price points.

For the fine-motor-skill-challenged folks like myself, a hot soldering iron and a lot of tiny and delicate electrical parts presents a potentially disastrous combination, and so I prefer to purchase my stereo components from the hands of the true experts. Fortunately for me, Mr. Van Alstine recognizes the many audio fans in my circumstance who are seeking great-sounding equipment without requiring a second mortgage to finance it. Building on the knowledge and insight accumulated over the years, AVA came to life, bringing with it amps, preamps and DACs.

AVA offers both solid-state and tube designs. The company’s website has a chart describing the differences between its preamp designs and the sonic signature of each. With four preamps in the current AVA lineup, I welcomed the opportunity to test its flagship, the Fet Valve CF hybrid preamplifier. Each circuit of our test unit features two 12AT7 tubes supplementing the gain stages and two 12AU7 tubes acting as cathode followers—from which this preamp gets its CF designate. According to AVA, this design represents “the very best we can currently do,” and so it is with high expectations that we at TONE anticipate hearing its sonic virtues.

Customization

AVA sells directly from its website and builds each product at the time of order. The company offers several options for the Fet Valve CF preamp, depending on the user’s needs and preferences. The entry point is the black faceplate model for $1,899. The same preamp with a silver faceplate starts at $2,099. From there, the owner has several upgrades to choose from. For those planning integration into a home theater setup, a bypass switch for the preamp is available for $50, allowing a surround-sound processor’s volume knob to act as master volume for the system. Vinyl fans will appreciate optional RIAA phono circuits, priced at $249. Inverter/bridge circuits and buffered tape output circuits are available for $199 each. And finally, a high-quality remote control with a mute button adds $299. With all the add-ons, a fully loaded Fet Valve CF runs in the neighborhood of $3,000.

Straightforward Setup

From a usage scenario, the Fet Valve CF could not be simpler. The back panel of our test unit offers a phono input, five line inputs, a tape input and output, plus two sets of main outputs. All connections are single-ended RCA.

On the front panel, from left to right, thee rotary knobs control source selection, volume and balance. Above the source knob, which selects from the six line inputs, are two toggle buttons. One offers a choice of stereo or mono playback; the other allows tape monitoring. Above the volume knob, two additional buttons control filter and low gain. According to AVA, these special settings offer the user more control over aggressive speakers and source material. As icing on the cake, the Fet Valve CF includes a 1/4-inch headphone output.

Listening

After several days of burn-in, the Fet Valve CF finally has its chance to sing. Sitting in the listening chair, I reset my mental sonic expectation to where my past experience with $2k preamps has placed it. There’s very good gear in this price range, but much of it requires some sonic tradeoff. The play button starts the music as expected, and surprisingly, it also activates my “mouth ajar” setting. The Fet Valve CF certainly offers a great first impression.

I use the term hybrid for this amp, which refers to both its sonics and its design. While the marvelous, fluid tube midrange is there, some of the downsides associated with older tube designs, like limited bass punch and definition, do not follow suit. In fact, the Fet Valve CF creates bass that’s quite deep and noticeable right out the gate.

While instruments and vocals retain a high degree of realism, there’s also a forgiving nature to the preamp’s sonic signature. Rendered digitally, some female vocal recordings, like Amy Winehouse’s Back to Black, retain a bit of grain and edge. Through this preamp’s lens, the excitement of the performance remains, while reducing these unwanted artifacts and retaining the underlying emotion of the original recording.

Saxophones and trumpets have an inherent potential for sonic sharpness. Recorded well, the sound captured from these instruments is one of incredible, live detail, but with some lesser-quality jazz recordings, a transparent window to untamed digital harshness can impart the listening experience with some unpleasantness. Striking an interesting balance, the Fet Valve CF places strident instruments in a slightly warmer light—which is not to say that the preamp creates an artificially sugary sound; to my ears, the sound remains generally neutral. Rather, it makes the best of what it’s given. Using the pass and filter toggles described earlier, the listener retains greater sonic control than most hi-fi preamps allow.

Music portrayed through the Fet Valve CF may not have the lush and nuanced refinement I’ve heard with more expensive gear, but this preamp certainly has a way of making lemonade from lemons. In addition to accurately conveying the woodiness of string instruments, the Fet Valve CF also offers a compelling representation of percussive instruments. Cymbals have the expected shimmer after a strike; snares retain the requisite rattle; triangles and tambourines have the ring they should. In general, this preamp retains symphonic music’s high degree of naturalness.

Compared with much more expensive reference gear, the Fet Valve CF creates a leanness to the sound. While it does a very good job reproducing both frequency extremes, it does have a somewhat reduced degree of richness and fullness by comparison. In orchestral pieces, the ambience of the performance hall is diminished. I also find that the width and depth of the stereo image through the Fet Valve CF is truncated. The music does not extend much beyond the left and right speaker limits. This preamp also struggles to project sound into the perceived space behind the speakers, although I will say that vocals never get recessed into the mix.

Despite these limitations, the sonic elements that reveal themselves between the speakers remain well separated and quite convincing. If forced to make a tradeoff, I’d prefer the Fet Valve CF’s large and realistically rendered sonic image—one that’s akin to stepping back several rows in a live performance—to having an artificially bloated image increasing the apparent size of vocalists or instruments. After getting used to the Fet Valve CF’s portrayal, I decide that it doesn’t reduce the enjoyment of the performance; it just puts a different lens on it.

Like the rest of the Fet Valve CF, the phonostage offers a fantastic price-to-performance ratio. While the sonic attributes described earlier remain generally consistent regardless of source, vinyl albums do take on a more relaxed musical presence though this preamp than their digital counterparts do. Considering the phono section is a mere $250 upgrade option, it’s an absolute steal. Even if you don’t have a turntable now, you might later!

Conclusions

Reviewing equipment involves critiquing the nuances of the musical presentation to determine strengths and weaknesses. But when that analysis is complete, it’s equally important to take a step back and listen to the music, not just the equipment. Does that piece of gear allow the listener to get pulled into the sound and forget the hi-fi behind it? With the Fet Valve CF, the answer is an unequivocal yes.

This preamp is one of those pieces of budget gear that excels on many, many levels. While much more expensive preamps residing in my test system may exceed the Fet Valve CF’s capability in various ways, this preamp never fails to provide musical fulfillment that exceeds expectations for its price point. It’s not perfect, but it’s also not saddled with any major compromises.

For those looking to build a home hi-fi system in the $8,000-to-$10,000 range, the AVA Fet Valve CF preamp can serve very well as an anchor component. Depending on the options chosen, $2,000 to 3,000 delivers great sound, leaving the rest of the budget for speakers, amp and sources that complement it. Do yourself a favor and keep this preamp in mind—it might just be the solution you are looking for.

Additional Listening

By Jeff Dorgay

Not quite old enough to have purchased tubed Dynaco gear new, I did spend a fair amount of time growing up with it—and I remember when Van Alstine came on the scene, offering updates that took this modest gear to killer levels. Frank has definitely taken everything further over the years, and he’s done so while keeping the costs in line.

If I had to describe Van Alstine gear in one word, it would be honest. This is well-made gear that delivers honest performance without frills. When I mate the Fet Valve CF to the Van Alstine Ultravalve vacuum tube amplifier, the synergy is fantastic, as you might expect. Using the two together with a handful of speakers, I don’t find the smallish soundstage that Jerold experienced to be an issue; it may have been system synergy. With the Fet Valve CF, everything from AVA’s own amplifier to a few examples from Pass Labs, Simaudio, Octave, and Audio Research all reveal the same big soundstage.

Van Alstine offers a 30-day trial on all of its gear, so you’ve got nothing to lose. I suspect precious few of these get sent back. This preamplifier is a proud addition to my list of Publisher’s Choice Awards for 2013.

Audio by Van Alstine Fet Valve CF Vacuum Tube Preamplifier

MSRP: Starting at $1,899

avahifi.com

The Maestro-50 digital amplifier from AVA Media is about the size of a hefty paperback novel and is aimed at the computer- and desktop-audio worlds.  This diminutive amplifier takes the approach of keeping the audio signal in the digital domain until the last possible step before it crosses over into analog.

The simple configuration of the $359 Maestro-50 begs the user to power it up first and examine it later.  I begin by connecting the amp to my MacBook using the TOSLINK cable, with a Shunyata Venom 3 power cord delivering the juice and Cardas speaker cables connecting it to a pair of Harbeth Compact 7ES-3s.  The solo piano of a live version of Jamie Cullum’s “Wheels” pops forth with all the quickness one would expect from ICE-powered amplification.  Having listened to live music in the lounge where this recording was made, I’m impressed by how the Maestro-50 gets the basics of the room’s tonal quality correct right out of the box.

Revisiting this track after a week of burn-in reveals less edginess and a more open high end.  The rolling keystrokes accompanying this catchy tune rapidly move from calm to intense, with Cullum’s slightly hoarse vocals now more clearly dominating the track—a definite improvement.

Simple, but Not Too Simple

The Maestro-50 is a basic-looking but handsome piece of equipment, with an enclosure sculpted from aluminum and anodized in a brushed black finish.  The CNC millwork is hand-finished with rounded edges.  The box measures 7 inches wide, 4.6 inches deep and 1.75 inches tall, with the front panel showing only an off-white LED and a small push-button volume knob—the ultimate in simplicity.  The back panel is just the opposite.  AVA was able to maximize this tiny bit of real estate to include a horizontal power-toggle switch, three-prong power-cord receptacle, S/PDIF, TOSLINK, subwoofer RCA out inputs and left and right female banana connections for the speaker outputs.  A USB-to-S/PDIF convertor can be ordered for an additional $62.

The Maestro-50 produces 25 watts per channel into 8 ohms, doubling into 4 ohms, which is plenty of juice to give impressions via the relatively inefficient Harbeths.  I incorporate a pair of ACI Emerald XL speakers (86 dB/watt) for the remaining listening sessions via my desktop system, also with excellent results.

The Maestro-50 is designed and manufactured in the United Kingdom by AVA, which is careful to point out that there is no built-in DAC in the amp’s conversion process.  The company use a process similar to that used by Steinway Lyngdorf, NAD and a few others, demodulating the signal right before it goes to the speaker outputs.  A full technical explanation is available at the website of Pure Audio Stream, a division of AVA Media that provides direct supply of AVA Media’s digital amps: www.pureaudiostream.com/technology.

The Maestro-50 is all about conveniently accessing music in a manner consistent with 21st-century convenience.  Users with an Apple AirPort Express can merely set up the Maestro-50 as a zone to be accessed with his or her iDevice, or even a Windows machine.  As with all digital amplifiers, electricity usage is minimal, so leaving it powered 24/7 will barely impact your electricity bill.

Further Listening

Sampling some Blue Note favorites, I find John Coltrane’s epic album Blue Train highly satisfying.  Coltrane’s signature sax sound is open, albeit slightly dry, but not enough to be a deal-breaker.  The Maestro-50’s quick transient response allows me to appreciate

Coltrane’s masterful finger work in the title track.  Lee Morgan’s trumpet is deliciously clear, making for foot-tapping fun.

The vocal harmonies of Lady Antebellum’s “American Honey” come through smooth and clear, with plenty of country twang.  The only place the Maestro falls short is with rich, resonant and more robust male vocalists like Johnny Cash.  The test speakers at my disposal all had a somewhat thin presentation here.

The amp’s lower bass output is respectable, with some punch, but those desiring a more robust bass response would do well to take advantage of the subwoofer output, adding the powered sub of their choice to the mix.  Our publisher reveals that the Maestro-50 does perform well with a more sensitive pair of speakers, like those from Zu Audio or Klipsch, so consider that as another option, should you really like to rock.

Final Score

The Maestro-50’s fresh design makes it an intriguing amplifier for the desktop and convenience-driven crowds.  By staying in the digital domain for inputs, it targets users who crave computer-based audio, and its sound quality makes for enjoyable all-day listening.

AVA Media Maestro-50 Digital Amplifier

MSRP: $359

www.ava-media.com

www.pureaudiostream.com

The finger snaps on Thomas Dolby’s “The Ability to Swing” hang in midair between the speakers, as Dolby’s highly processed yet ethereal vocal enters the mix.  “It isn’t worth a bean, if you haven’t got the ability to swing,” he declares.

Indeed, the six-figure system assembled in room two is in full swing right now, but the amplifier powering the Sonus faber Guarneri Evolution speakers is the humble AVA Ultravalve, not the $65,000 Octave Jubilee monoblocks I’ve been using for some time.  This is truly an amazing amplifier.  If I powder-coated the chassis a certain shade of blue-green, slapped an Air Tight badge on the front panel and told you I paid five figures for this little jewel, you’d believe me—it’s that good.

With so much excitement about the vinyl resurgence of the last few years, some of you have forgotten how popular vacuum tubes have also become lately.  Yet, in the midst of these newer products sprouting up, it’s easy to forget some of the players that have been around for quite a while.  Audio by Van Alstine (AVA) is that “other” amplifier company in Minnesota—Audio Research is located nearby—and it is a perfect example of a manufacturer that has quietly gone about its business making great products without a ton of fanfare.  And you rarely see products from AVA for sale on the secondary market.  The company obviously has a legion of loyal customers,

No matter how much time I spend with mega-dollar power amplifiers, I always love a variation on the Dynaco Stereo 70 theme.  While I’ve never heard one that I didn’t like, there are big differences between them.  Some have a softer, warmer presentation and definitely embellish more than others; the original ST 70 is the prime example of that voicing.  With these types of amps, your best recordings don’t sound much better than your worst, but everything sounds somewhat liquid and dreamy—not a bad place to hang your hat if you have a modest system, or a lot of MP3s.

Tube Through and Through

Frank Van Alstine has been at this game for a long time.  He started out modding and repairing Dynaco electronics 30-plus years ago, and revamped the ST 70 circuit so much over the years that it is now truly his own design now.  The Ultravalve is still based on a pair of 6CA7 output tubes (EL34 or KT77 tubes can be used as well), but it does not have a switch for triode mode, fancy power output meters or anything that distracts from the amplifier’s performance.  And its price is right: $1,999 puts one in your hot little hands.

Like the original ST 70, the Ultravalve uses a 5AR4 rectifier tube and a pair of more readily available 6GH8A small-signal tubes in place of the now long-obsolete 7199 tubes in the ST 70, which is fetching premium prices online.  The Ultravalve is one of the first power amplifiers I’ve listened to with which I just don’t feel the need to roll tubes.  It sounds just fine as is, and a little bit of research shows that there aren’t a lot of variations on the 6GH8A tube anyway.  Perusing Mr. Van Alstine’s board on the AudioCircle forum shows him to be a practical man, so I just enjoyed the amp’s stock tubes.

I do upgrade the power cord to a Cardas Clear cord for my review, only because that’s what I use with everything else and we value consistency here.  The Ultravalve does benefit slightly from the upgraded power cord and from being plugged into a Running Springs Dmitri power conditioner.  But keep in mind that none of this is necessary to enjoy the Ultravalve.

Removing the bottom panel of the highly polished stainless steel chassis reveals tidy workmanship throughout, again showing that AVA sticks to the basic layout of a ST 70: driver circuitry on a well-thought-out PC board and the rest of the amplifier wired point to point.  There is a switch on the rear panel to float the ground, as well as three binding posts for 4-, 8- and 16-ohm speakers; this is my only gripe with the Ultravalve.  It really could use some beefier binding posts for those of us with bigger speaker cables.  My solution is just to re-terminate with bananas plugs.

Ace of Bass and Dynamics

Bass control is a big part of the equation here.  The original ST 70 has a puny power supply and it shows up in the playback, with the bass response lacking dynamics and sounding wild and wooly.  An original Conrad-Johnson MV50 isn’t much better.  An original Marantz 8B has a more liquid midrange but still falls short down under.

As brilliant as the Sonus faber Guareri Evolution speakers are, like any high-performance Italian product, they are a bit picky about what you feed them.  Just like my Fiat Abarth getting grumpy when filled with anything less than premium gas, the Evos need current and control to give a stellar performance and sound as big as they should.

And when delivering Nine Inch Nails’ “Help Me I Am in Hell,” the Ultravalve sounds big. I move the amp out into room one, with the KEF Blades (with their 90-dB-per-watt sensitivity), and it sounds damn big, with guitars floating around the soundstage and the heartbeat at the end of the track filling the listening room.  Upping the game with a much more densely recorded track, “Mr. Self Destruct” from NIN’s album The Downward Spiral, I find that the Ultravalve not only keeps the groove of the driving synth bass well intact, but it also does not lose the focus.  The amp starts and stops on a dime as Trent Reznor brings the music to barely a whisper, only to audibly assault us again and again with a huge ball of sound and dynamics.

It’s still hard to believe I’m listening to a $2,000 amplifier.  For those of you in the audience thinking that it’s sheer insanity to put an amplifier like this in a system like this, I submit that it’s the only way to see what its performance envelope truly is.  Daft Punk’s Homework lights up the Blades and I can turn the volume up to the point where I feel like I’m back in New York at Fashion Week.  All that’s missing is the catwalk.

The Ultravalve carefully follows Stanley Clarke as he rips up the fretboard on “Bass Folk Song No. 7,” clearly demonstrating its ability to keep the Blade’s 9-inch woofers in control.  The amp reveals Clarke’s delicate touch on the fretless bass, and it never gets sloppy, slow or wooly.

It’s also Got Top

The Ultravalve is ultra quick, even when playing a less-than-superb recording, like The Stooges self-titled album, on which the amp keeps its composure, provided you don’t turn the volume past the point of soft clipping.  Rather than getting harsh, like many other low-powered tube amplifiers we’ve auditioned, the Ultravalve begins to suffer from a collapsed soundstage.  This degradation is slow at first, but the amp then quickly slides into the same flat, brick-walled sound that plagues many of today’s digital recordings.  But if you keep the Ultravalve within its comfort zone, you’ll be handsomely rewarded.

Miles Davis’ “Diane,” from Steamin’ with The Miles Davis Quintet, proves open and spacious, with Philly Joe Jones’ brushwork on the drums exquisitely rendered, as Davis floats through the soundstage.  This amplifier becomes more convincing the longer you listen; about an hour is required for it to open up completely, but it is still damn good two minutes after initial turn on.

Perhaps the only stretch for the Ultravalve while paired with less than highly efficient speakers comes when asking it to reproduce large-scale orchestral pieces or electronica at club levels.  Prokofiev’s suite from The Love for Three Oranges taxes the Ultravalve as the large kettle drums reach full throttle, requiring listening at less than what might be considered a live level—but how often do you do that?

Back to Earth

Using the Ultravalve with similarly priced components is highly rewarding.  It is fully capable of anchoring a modestly priced but high-performance system.  Mating the amp to a Conrad-Johnson PV-12 preamplifier (with CJ’s recent capacitor updates), an Oppo BDP-105 universal player and the Rega RP6 turntable, with a pair of KEF LS50 speakers, proves breathtaking—especially for a relatively inexpensive system like this one.  But you’ll be surprised just how damn good the Ultravavle sounds as part of a no-holds-barred system.

While the 35 watts per channel of the Ultravalve may not be enough juice for everyone, if that much wattage will work for you, I cannot recommend this amp highly enough.  The level of resolution, tonality and bass control this amplifier offers for $1,999 is unmatched by anything I’ve ever experienced at this price point.  I am very proud to award the Ultravalve one of our Exceptional Value Awards for 2013.  I’m keeping this one!

AVA Ultravalve Vacuum Tube Amplifier

MSRP: $1,999

Audio by Van Alstine (AVA)

www.avahifi.com

Peripherals

Analog Source	SME 10 turntable    Sumiko Palo Santos cartridge    Aesthetix Rhea phonostage
Digital Source	dCS Vivaldi stack    Oppo BDP-105
Preamplifier	Conrad-Johnson PV-12c1    Nagra Jazz    Robert Koda K-10
Speakers	Dynaudio Confidence C1    KEF LS50    KEF Blade    GamuT S9    Sonus faber Guarneri Evolution
Cable	Cardas Clear