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

en.unisonresearch.com (Factory site)

www.colleencardasimports.com (US Importer)