Note: Measurements can be found through this link.

Wadia came into being in Minnesota, in 1988, because several engineers who then worked for 3M were unhappy with the quality of the sound of early digital audio and CD players. They wanted to improve that sound quality by applying the more sophisticated technologies they’d worked with in their research into digital telecommunications.

Today, Wadia is based in Binghamton, New York, where it is a member of the McIntosh Group of audio companies, sharing overall corporate management, technical design, and development with several other well-known names: Audio Research, McIntosh Laboratory, Pryma, Sonus Faber, and Sumiko Subwoofers. Binghamton is also where the subject of this review was manufactured: the a315 stereo amplifier ($3500 USD). Electronic design and specification of the a315 were handled by McIntosh’s US-based engineering team, while its industrial design and styling were done by their industrial design team, based in Italy. Within the McIntosh Group, Wadia is the newer-technology brand, proffering more recently developed methods of sound reproduction, such as the class-D amplifier technology on which the a315 is based.

Description

Because the Wadia a315 is a class-D amplifier, I’d assumed it would come in a fairly small package, as do so many other class-D amps I’ve seen and heard -- because class-D operation is far more efficient than traditional class-AB, it generates much less heat, and so doesn’t need the massive heatsinks that account for much of the size and weight of class-AB designs. It was only when a surprisingly large box emblazoned with Wadia’s logo arrived that I realized just how wrong I was. When I’d extracted the sturdy-feeling a315 from its high-quality packing and set it down among my other gear, I saw that it measures nearly 18”W x 20”D -- it takes up a lot of space. It’s relatively short at 3 3/8”H, including feet, but weighs a substantial 27 pounds. The a315 shares styling with Wadia’s di322 D/A converter, recently reviewed for SoundStage! Ultra by Jeff Fritz.

The a315’s thick, mostly flat faceplate has a nice bevel along its top edge. On that front panel, at the right, is a small Standby/On button surmounted by an LED indicator, just above the model name in small type. At the left, a large, paraboloid-shaped depression contains the Wadia logo in white, replacing the sharply machined notch and engraved logo of years past. The rear and side panels match the front in style and silver color, and are joined to the front with rounded corner pieces that curve downward along the bottom edge to form small, rubber-bottomed feet. The nearly uniform styling of all four sides gives the a315 a more finished appearance than do the cases of most amplifiers, with their strictly utilitarian backsides. The top panel of glossy black glass, “Wadia” emblazoned in white at its center, contrasts sharply with the lighter, silver-colored case. When the a315 is powered on, both this name and the logo on the front panel are backlit. No screws or connectors are visible from the top, front, or sides to detract from this extremely attractive design. The fit and finish are excellent.

All connections are made within a long, shallow, black recess nicely framed by the styled silver of the surrounding rear panel. These include, on the left, an IEC-compatible power-cord inlet and four easy-to-use, gold-plated, five-way speaker binding posts. Toward the right are single trigger in and out ports, as well as gold-plated left- and right-channel pairs of balanced (XLR) and unbalanced (RCA) inputs. There are also intuitively labeled control switches for selecting balanced (BAL) or unbalanced (UNBAL) operation, and to enable (ENA) or disable (DIS) the power-save circuit, which automatically returns the a315 to standby mode if an audio signal is not detected for about 30 minutes.

The a315 is specified to deliver 150Wpc into 8 ohms or 250Wpc into 4 ohms (both 20Hz-20kHz). Its circuit design includes Frequency Switching Transmission (FST), which Wadia says “assures full output power is delivered over the entire audio frequency spectrum”; and a Signal Surveyor, which “monitors the output signal and stops amplification of unsafe levels if DC is detected, thus protecting your speakers.” Power output was never a problem during my listening -- driving my KEF R900 speakers, which boast above-average sensitivity of 90dB/2.83V/m, the a315 never failed to keep up, despite being asked for ever-increasing volume levels as, in English Ale-inflected sessions of old and new favorites, hours of middle-aged reverie went by.

The efficiency of its class-D design means that the a315 consumes much less power than the norm. Wadia claims that the a315 is 68% efficient when operating at 1/8 full power, and 88% efficient at full power. That’s a notable improvement over the 50-60% efficiency of typical class-AB amps such as my own reference, an Audio Research D300. In use, the a315 barely felt warm to the touch. Its circuits are printed on what Wadia describes as boards of “high-quality” fiberglass, with copper-clad traces; the parts are mostly surface-mount devices; the larger, heavier components are through-hole attached. Wadia provides two specs of the a315’s total harmonic distortion (THD): less than 0.1% from 250mW to half full power, and less than 0.5% from half to full power, both from 20Hz to 20kHz. According to Wadia, the a315’s signal/noise ratios are 90dB via its balanced inputs, and 88dB through its unbalanced inputs, both A-weighted.

Setup

I recently got an older Apple iMac and have successfully transformed it into a dedicated music server running iTunes and the Tidal music-streaming service. The iMac is connected to my Benchmark Media Systems DAC2 HGC digital-to-analog converter via a Nordost Blue Heaven USB cable. During my time with the Wadia a315, I connected the Benchmark DAC to my Hegel Music Systems P20 preamplifier, and the P20 to the a315 via Dynamique Audio Shadow balanced interconnects. The Wadia drove my KEF R900 speakers through spade-terminated Transparent Audio MusicWave Ultra cables. For comparison, I used my reference Audio Research D300 stereo amplifier (discontinued; $3995 when last available), which puts out 160Wpc into 8 ohms; as well as Simaudio’s Moon Neo 330A stereo amplifier ($4300), specced to output 125Wpc into 8 ohms, and which I’d just finished reviewing.

Listening

Trent Reznor wore most of the hats in his band, Nine Inch Nails -- he wrote, sang lead, played most of the instruments, and produced. To my ears, he’s always made wildly bizarre music -- I usually find myself enjoying the complexity and layering of his compositions even as I feel disturbed by his mind-bending distortions and unusual edits of the sounds of traditional instruments. “Just Like You Imagined,” from Nine Inch Nails’ The Fragile (16-bit/44.1kHz FLAC, Nothing/Tidal), is no exception. The introduction is a neatly orchestrated mix of what sound like highly distorted guitar and electronic tones. A mostly traditional-sounding piano enters into the mix, lending a stabilizing melody to the morass of highly edited noise. But through the a315, what most caught my ear was the entrance of the next instrument: midsize drums struck with force, sounding surprisingly unaltered and natural in a recording that includes so much studio processing and editing. These unfettered drum beats sounded remarkably clear through the Wadia -- maybe it was the way the drum or its microphone was positioned, or maybe the mix in finalizing the track; whatever it was, the Wadia a315 so loved to reproduce the clear impact of drumstick slapping the taut head of a drum that I could almost “see” the waves of air rolling outward from the skin -- not unlike concentric ripples moving outward from the point where a stone has been dropped in water. The precisely positioned drumstrokes stood out as vividly real amid the chaos of warped sounds around them.

In 1985, Men at Work released their third album, the largely ignored Two Hearts. I think it’s well recorded, and through the Wadia a315 it sounded mostly devoid of the early-digital harshness of so many CDs of that era. In “Maria,” Colin Hay’s voice jumped confidently onto the soundstage after a brief intro of maracas and effects-laden guitar, then lingered clearly in its own space with just a bit of reverb. Hay’s voice is not bass heavy, but his slightly raspy sound as he strains for the higher pitches was presented clearly in a nice contrast to Renée Geyer’s silky-smooth voice blooming atop the sounds from the rest of the band. The low to upper midrange was very present in the sounds of these two voices -- they had weight. Certain aspects of the sound of this track, including Hay’s sibilants, and the higher-pitched electric guitar and synthesizer melodies, are slightly edgy -- I chalk this up mostly to when it was recorded. As I said, Two Hearts is mostly devoid of early-digital harshness; the Wadia a315 was resolving enough to let what flaws it has show through.

I changed genres and listened to Siegfried’s Funeral March, from Wagner’s Götterdämmerung, with the Metropolitan Opera Orchestra conducted by James Levine, from the compilation The Compact “Ring” (16/44.1 AIFF, Deutsche Grammophon). Through the a315, the huge sound of the full orchestra was spread liberally between my speakers, though the entire sound was slightly laid-back and relaxed, compared to how it sounds through more in-your-face amplifiers, such as Simaudio’s Moon Neo 330A (see below). Even the Met orchestra’s usually forward-sounding brass maintained their distance in playback. Because of that laid-back sound, I felt no sense of urgency in any part of this excerpt -- even the fabulous crashes of the climax sounded somewhat reserved through the a315, diminishing the impact of the work as a whole. Left-to-right imaging was solid with the a315 -- I could discern the various sections of the orchestra with ease, and easily pinpoint the timpani at the rear, just to right of center. However, soundstage depth -- particularly, the delineation of what was toward the front of the stage and what was at the rear -- was a bit harder to visualize. Overall, the orchestra felt shallower from front to back in the most thunderous portions, compared to the depth I’m used to with my reference Audio Research D300. The quieter sections and the passages for unaccompanied timpani gave greater impressions of depth, but overall, the stage was shallower.

J.S. Bach’s Toccata & Fugue in d, BWV 565, is a fun and lively piece for pipe organ that I enjoy playing more often than normal people might. My recording is of a performance by E. Power Biggs from a 1990 compilation, Bach: Great Organ Favorites (16/44.1 AIFF, Sony Classical). The a315 presented a clean but, again, relaxed sound, and Biggs’s left- and right-hand runs across most of the keyboard were well articulated, each note arriving and departing in a soft blend with its neighbors. The a315 reproduced the deeper bass notes with an emphasis that sounded like plumpness; however, while this plumpness helped give the low end a certain fullness, the actual bass depth the Wadia reached was less than I’ve heard with other amps. In short, the a315’s bass sounded full, but didn’t seem to present the deep bass as forcefully as I thought it should.

While not as frenetic as some of today’s electronica, “Ceremony,” from Belleville’s Sunsets & Nightfalls (16/44.1 FLAC, Belleville Beats/Tidal), balances the newish habit of marrying 1980s-style electronics and processed vocals with today’s familiar, heavy bass rhythms. It begins with a gracefully flowing melody in the midrange underlaid with snappy, deeper beats that channel a bass guitar. Nearly everything in this track is subjected to lengthy reverb, which creates a limited sense of depth. The female voice is sudden, immediate, and less processed-sounding among the long-decay electronics, while the sound of the male voice is somewhat more distant and lingers longer. The sibilants sung by each had a bit of sizzle, but not enough to draw too much attention. I could not only easily “see” the voices on the soundstage, they were also somewhat emphasized, as if illuminated by spotlight on a darkened stage -- surprising, given the a315’s otherwise somewhat laid-back sound. The airy and percussive electronic-produced melodies were also easy to pinpoint in space as they were panned from left to right and back again. The laid-back sound I’d noticed with the Wagner was clearly present here -- the music seemed to linger at a distance, with a velvety-smooth quality. Overall, I found the a315’s rendering of “Ceremony” quite refined.

Comparisons

The a315 sounded very similar to my reference Audio Research D300, with some subtle differences. Putting an ear to my KEF R900 speakers with no input signal showed that the Wadia had a lower noise floor when running than did the D300, which emitted a mild hiss; the a315 produced virtually nothing. The D300 did produce greater bass slam and extension, with a bottom end that was tighter and deeper than the a315’s. However, the a315’s midrange was the equal of the sweet mids of the D300, the product of a company that began by building tubed equipment, and to this day still does. Both the Wadia and the ARC evinced a center-of-the-spectrum sweetness in the Wagner and Bach recordings -- with both, the quality of their midrange reproduction stood out above all. The D300’s soundstages were wider and deeper than the Wadia’s, though by only fine margins.

The a315 seems better built and is much more visually attractive than Simaudio’s Moon Neo 330A -- surprising, given that it costs $800 less. However, the Wadia sounded notably less neutral than the Simaudio, particularly at the frequency extremes -- the 330A was more extended at the top and more forceful at the bottom. The two amps’ precision of left/right imaging were comparable, though I found the Neo 330A better at rendering depth. The Simaudio was brutally neutral and clear in my system; the a315, by contrast, had a more graceful, laid-back sound, with a subtle softness that was alluring without losing vital midrange clarity. The ARC D300 and Wadia a315 sounded more alike than different; the a315 and the Moon Neo 330A sounded more different than alike.

Conclusion

Wadia’s a315 stereo power amplifier is a visually attractive component that appeals to my sense of style and design -- it feels as solid as it looks beautiful, and everything I touch, from the power button to the input connectors to the speaker binding posts, has a high-quality feel. It looks and feels like an amplifier that costs much more than $3500.

The a315 drove my speakers as loudly as I needed them to be driven, and exhibited a musical warmth from the midbass through the mid-treble -- I can’t imagine too many speakers it won’t work well with. I found its midrange smooth and lovely overall, and its bass to have a certain plumpness and bloom. However, it was slightly reticent at the extremes of high and low frequencies, and while its positioning of aural images on soundstages was consistently precise, I didn’t find those stages to be as deep as with the Audio Research D300 or the Simaudio Moon Neo 330A. Overall, the a315 offers a smooth, refined sound with a bit of character; listeners considering buying one should definitely first try it with their own speakers and system.

. . . Erich Wetzel
erichw@soundstagenetwork.com

Associated Equipment

• Loudspeakers -- KEF R900
• Headphones -- Bowers & Wilkins C5, NAD Viso HP50
• Preamplifiers -- Benchmark Media Systems DAC2 HGC, Hegel Music Systems P20, Simaudio Moon Neo 350P
• Amplifiers -- Audio Research D300, Simaudio Moon Neo 330A
• Source -- Apple iMac running Mac OS 10.11.6, iTunes, Tidal HiFi streaming service
• Digital-to-analog converter -- Benchmark Media Systems DAC2 HGC
• Speaker cables -- Transparent Audio MusicWave Ultra
• Interconnects -- AudioQuest King Cobra XLR and Ruby RCA, Dynamique Audio Shadow XLR, Transparent Audio MusicLink Super RCA
• USB Cable -- Nordost Blue Heaven

Wadia a315 Stereo Amplifier
Price: $3500 USD.
Warranty: Three years parts and labor.

Wadia
2 Chambers Street
Binghamton, NY 13903
Phone: (607) 723-3539
Fax: (607) 724-0549

Website: www.wadia.com