Audio by Van Alstine Fet Valve CF Vacuum Tube Preamplifier

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.


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.


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!


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

Unison Research Phono One Valve Phonostage

Vinyl lovers have no lack of choices these days when it comes to purchasing a phonostage.  Whether you’re an analog beginner or a veteran, your needs are covered from the entry-level price point all the way to the mega-buck region.  But when narrowing down the characteristics and features that are of particular importance, the choices start to thin out a bit: outboard power supply, check; great build quality, check; great cosmetics, check; tube based, check; good cartridge-loading options, check; Class-A zero-feedback design, check; Italian, check.  Italian?  If you’ve checked all of those boxes then you’ve arrived at Unison Research.

The $3,295 Phono One is a rather attractive product from the Italian firm.  Unlike the usual aluminum box, this beauty features a black-powder-coated steel case, along with a wood front panel and a sculptured wood accent panel on the top—which gives the phonostage a unique look and provides damping.

The power supply is housed in a separate enclosure, which an umbilical cord connects to the main chassis.  This separation is very critical in phono applications where the signal is delivered at such low levels; in a tube-based product it becomes even more important.  Using an external power supply is not the cheapest way to build a phono preamplifier, but it insures low noise and prevents the delicate phono signal from being contaminated by power-supply noise.

Peeking inside the main chassis reveals nicely laid out circuit boards populated with quality parts.  The board containing the tubes is separate from the RIAA EQ section, and isolated from the chassis via four rubber grommets—a nice feature that reduces any sort of vibration coming from outside the unit, and damps any possible microphonics coming from the tubes themselves.  The five tubes in this section are new production Tung Sol 12AX7s.  I did all my listening with the supplied tubes, eschewing my usual enthusiasm for tube rolling, because all of my favorite matched 12AX7s are quads!

Easily Adjustable

The back panel of the main chassis offers gold-plated RCA connectors for input and output, along with DIP switches for cartridge loading.  MC-resistive loading options are set at 20, 50 and 100 ohms, which is enough to cover most of today’s MC cartridges.  For moving magnet, the ubiquitous 47k ohm is the only option, though capacitance can be set at 100, 200, 320 and 420 pF.  An Ortofon MC 20 Super 25th Anniversary and a recently restored Lyra Clavis provide the basis for most of my MC listening, with a NOS Acutex 412 STR and a tried-and-true Shure V 15 Type IV for MM duties.

Beginning with the Lyra Clavis loaded at 100 ohms proves palatable (even though this cartridge usually requires a higher load) in concert with the latest Audience Au24SE phono cable, which is a favorite here at TONEAudio.  This cable is optimized for cartridges with low internal impedance, such as the Lyra and Ortofon.  When I switch to the Shure and Acutex MM cartridges, I use an AudioQuest King Cobra cable from the tonearm to the phonostage, achieving outstanding results with both setups.

The first LP on deck is Nina Simone’s Pastel Blues.  The song “Chilly Winds Don’t Blow” showcases her distinctive voice, which can be irritating unless everything in the chain is near perfect.  In this case, her generally high-pitched tone comes through in great detail but with a welcome smoothness in the higher registers.  The Ortofon proves best at the 20-ohm setting, but both of these extremely low-output MC carts expose the noise floor in the Phono One—our publisher has better results with MC carts in the .5-MV range.  (See “Additional Listening” below.)

Next up is The Soundtrack of Our Lives, with “In Someone Else’s Mind” from the Behind the Music album.  This Pink Floyd-ish tune features double vocals that the Phono One easily unravels and separates in the sound stage, with background percussion and droning sound effects placed way back, even behind the music.  Peter Gabriel’s debut solo album, a Direct-Disk Labs reissue of the original Atco Records release, again proves that the Phono One is a natural performer.  The phonostage easily handles the soaring crescendos at the end of “Humdrum,” separating the various instruments and studio effects while keeping the vocals completely intelligible, even at the highest levels.

Act Two

When I switch to my MM cartridges, the Phono One really starts to shine.  I don’t know whether the MM stage received extra attention during the engineering phase or whether my MC cartridges simply did not have complete synergy with the product.  In any case, the big bang comes from the lowly Shure cart for the rest of the evaluation period.  As in all things vinyl, you never know what’s going to sound best until you’ve run down all the options.

Esperanza Spalding’s Junjo begins the second round of evaluations in earnest.  On the leadoff composition, “The Peacocks,” the Phono One presents the instruments in space and in a beautiful front-to-back fashion.  The drum kit exhibits tremendous attack, while the cymbals show intricate detail without distracting from the rest of the mix.  And, of course, Spalding’s bass lines are muscular and clearly delineated.

Anne Bisson’s album Blue Mind serves as the obligatory female vocal demo.  The song “Camilio” is a mournful, quiet ballad.  The Phono One conveys the full emotion of the song through Bisson’s breathy voice, which floats exactly between the speakers, while the phonostage presents the acoustic bass as a strong foundation.  If you’ve had the chance to hear Bisson sing up close and personal at any of the recent hi-fi shows, you’ll recognize this instantly.  My final choice is Steve Miller’s Born 2 B Blue album.  The tune “Ya Ya” is a wonderfully recorded affair and sounds fantastic through the Phono One.  The highest compliment I can pay this phonostage is to say that it will allow you to take off your audiophile hat and let you just get into the music—no chin-stroking analysis required here.

The inner tweakazoid in me experiments with a few power cords at the end of the evaluation, just to see if more performance can be wrung from this Italian beauty.  After four tries, I settle on the Crystal Cable Ultra, which provides the best combination of speed, dynamics and musicality.  After getting used to this combination, I switch back to the stock cord, and quickly realize that a good power cord is a worthy upgrade for the Phono One.

With so many phonostages vying for your dollar, the Phono One is at the high side of the price range for what it offers; but, with an excellent electrical and physical design, the Phono One is a wonderful alternative to another stamped-out black box.  And now, with Colleen Cardas added to the dealer network as the U.S. importer, this Italian wonder is easier than ever to experience outside of a hi-fi show, and that’s a good thing.

Additional Listening

By Jeff Dorgay

I was instantly drawn to the visual style of the Phono One, but then I’m a sucker for all things Italian.  And the price doesn’t put me off either; I’ll always pay a few extra bucks for style points.  That’s why I drive a Fiat Abarth instead of a Hyundai Veloster.

Following Mr. O’Brien’s lead, I try a handful of MC cartridges with slightly higher outputs.  Sticking with Ortofon, the Cadenza Bronze MC, with its neutral tonal balance and .4-MV output, proves perfect in room two; I mount the Cadenza on an SME 10 turntable with SME V tonearm (and this cartridge works incredibly well when loaded at 100 ohms).  The Rega Apheta MC, which works best at lower loading, provides incredible synergy loaded at 20 ohms via the Phono One, which delivers what is perhaps the best performance I’ve ever experienced with this cartridge.

The Grado Statement 1 also proves fantastic with the Phono One; its .5-MV output and 47k loading requirements are no problem at all, underlining the fact that you can mate this phonostage with a premium cartridge in the $2,000-to-$3,000 range.

Finally, swapping the factory tubes for a full set of EAT tubes transforms this great preamplifier to an exceptional one:  Dynamics improve and noise drops, so I’ll go out on a limb and suggest tube rolling with this one—just make sure you get five matched tubes.

The Phono One is certainly good enough to be purchased for our ever-growing fleet of phonostages, so we will report back towards the end of the year, with a long-term follow-up, after it has been used with an even wider range of phono cartridges. – Jerold O’Brien

Unison Research Phono One Valve Phonostage

MSRP: $3,295 (Factory site) (US Importer)

Icon Audio PS2 Valve Phonostage

If you were to step back into time to the 1950s and look at the decade’s small-scale manufacturing, you’d likely find companies that valued resources, hand-built products, viewed quality over consumerism, took simplified approaches to design, and supplied customers with a most precious commodity: time. Specifically, time to provide support, repair products new and old, and stage face-to-face consultations.

David Shaw’s UK-based Icon Audio follows such a manufacturing philosophy in 2011. Utilizing valves as a mainstay in its products, Shaw constructs products to last. “I’m not a keen environmentalist,” he says, “but I hate to see resources wasted where transformers, chassis, and the like are buried in land-fill. If they’re designed correctly in the first place, it’s economic to fix them. We like hardwiring in our design, which makes repair [easy].”

At heart, Shaw’s designs are socialist—hi-fi for the working classes, as it where. In fact, you could dress Shaw up in miner’s clothes polluted with coal dust or watch him emerge grease-caked from underneath a repaired car and find his deportment, speech, and manner genuinely believable. Primarily offering amplifiers as well as the odd CD and speaker product, Shaw designs luxury products for the rest of us. The approach has resulted in Icon Audio forging a reputation for providing outstanding sound quality at very reasonable prices.

“I realize that if someone has a family and other commitments, their disposable income is often limited. Yes, I’m here to make money, but I wanted to fill the space, providing products for them,” he claims.

The PS2, a moving-magnet phono amplifier, is one such product. Created as a simplified one-box version of the company’s two-box PS1 phono amp, it plugs a budget-model gap in Icon Audio’s lineup.

“We used a simplified power supply and a lot of jiggery pokery to try and get the transformer in there so if won’t cause too much of a problem with noise,” comments Shaw. “It uses the same circuits as the more expensive PS1. I used Mullard valves (ECC 803) or the American equivalent—the 12AX7.”

Valve Selection

Choosing valves is critical. They must be as sympathetic as possible with the typical RIAA curve found on a majority of vinyl albums in order to detract the focus away from pops, clicks, and surface noise. According to Shaw, valves also remove the distortion effects found within a typical solid-state phono amplifier that, when compared to a valve’s infinite margin, has limited signal headroom.

“These valves are also used in the PS1 phono amp,” adds Shaw, “and the power supply is designed sympathetically but simplified so the performance is not degraded to any extent. The construction is completely metal. I used to work in the plastics industry for a time and know that plastics degrade relatively quickly. So I use solid aluminium for the chassis and a solid-steel bottom.”

In keeping with Shaw’s design tenets, the chassis is suitably simple. Spanning 10.5” x 5.5” x 27.5” and weighing in at 5.5 pounds, the front provides a power switch and light indicator. The input/output phono sockets, ground connector, toggled earth lift (to reduce possible hum), and fixed power cable are found along the rear.

Sounding off

Spinning Mobile Fidelity’s edition of the Pixies’ “Where Is My Mind?” from Surfer Rosa, the PS2 exhibited a airy midrange and sparkling treble espoused by Frank Black’s often-cutting vocal delivery and Joey Santiago’s acerbic, soaring guitar wails. It all transpired within a beautifully constructed 3D soundstage.

Before I went any further with listening, I ran the PS2 alongside a solid-state phono amp in order to provide technological contrast. Enter the well-regarded A.N.T Kora (£325). One aspect immediately became apparent. The PS2’s gain was notably higher, by a factor of six or seven notches on my preamp. Even at low volumes, the Kora yielded a high degree of bass drive, with a slight midrange recess that contrasted with the PS2’s cleaner upper frequencies and slightly slimmer bass array. The PS2’s reduction of inherent distortion on LPs encouraged me to increase the volume, a decision that, in turn, enhanced vinyl’s musicality and brought forward more information. In addition, the Icon provided an enhanced instrumental separation that successfully improved clarity and boosted transparency.

Moving onto Kate Bush’s “Mrs Bartolozzi”, a challenging solo piano track fromAerial, told me even more. Despite the A.N.T.’s admirable detail retrieval efforts, the PS2 did a superior job conveying the emotions behind the words, adding consistency and weight, as well as showcasing greater depth and nuance. The PS2’s bass output lacks some depth but feels more truthful to the ear. In addition, when experienced through the PS2, bass possessed more body and structure. The piano danced around Bush with a rhythmic lucidity that dodged in and around her singing.

Contrasting the largely organic noises of the Pixies and Kate Bush came courtesy of the synth-based noodlings of electronica group Autechre’s Circhsuite. Putting the busy, cacophonous electronic output into an orchestral-like arrangement, the A.N.T displayed admirable clarity and enhanced bass. The PS2, however, offered more pizzazz, extra sparkle, and greater sense of life. Upper frequencies were extended, and the bass felt cleaner. Moreover, the PS2 ably separated the conglomeration of electronic noises into recognizable tones, enhancing the musical interaction.


Since the PS2 is stuffed into a single box, noise is slightly higher than that of a phono amp within a two-box configuration. But it’s not intrusive, and quality is maintained in both construction and sound that, for the price, is impressive. And the £450 cost is important: Users can now go valve without having to shell out for an outrageously expensive design that doubles as a piece of object d’art. The PS2 allows you to discover what all the fuss is about and realize just what a valve-based phono amp can do. – Paul Rigby

Icon Audio PS2



Analogue Source Pro-ject Essential turntable
Preamplifier A.N.T. Kora 3T Special Edition MM phono stage    Aesthetix Calypso Preamp
Power Icon MB845 Monoblocks
Speakers AE Revolution One
Cables Avid SCT    Avid ASC