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PS Audio GCA-250 Dual Mono Hybrid Analog/Digital Switching Power Amplifier

Part II

October, 2005

Jason Victor Serinus

 

The Sound

Many people prefer solid state over tube amplification because of its solid, tight bass and neutral midrange (as opposed to fat, lush, or rich). If those are your primary concerns, the GCA-250 may make you very happy.

My initial concern with any solid state amplification is that it may sound overly harsh or bright. Not an issue with this amp. There is no way that anyone will accuse the GCA of having one-dimensional bright or brittle sound. I found the amp eminently listenable, and neutral to a fault.

Let me elucidate. In the lower range, the GCA-250 packs a mighty punch. Bass is tight and well defined.

Of equal import, bass is beautifully detailed. On my frequently auditioned Reference Recordings disc of Rachmaninoff's Symphonic Dances, I was able to clearly differentiate layers of bass instruments, from percussion, double basses and tubas, up to cellos and violas. There was absolutely no smudging of instrumental line. I was greatly impressed by the amp's ability to clearly communicate these lines, and to do so with great speed.

The GCA-250's healthy midrange, frequently illusive if not absent entirely from lower priced solid state components, was equally admirable. Every instrument had realistic body and depth, with undertones quite prominent.

I cannot pretend that the air surrounding instruments and voices was the same as with my reference tube amplification. Yet, with soundstages of equal width and height, the presentation was certainly credible.

Where the GCA also stood out, and not always to my preference, was in its absence of top end brilliance. On Rachmaninoff's Symphonic Dances, for example, the triangle certainly rang, but its vibration in space seemed damped. I could hear the initial hit, for sure, but the sound seemed thin. With reverberation in space diminished, it also seemed of less consequence.

For me, this is a major issue. Orchestral composers use triangles sparingly, summoning forth their brilliance as a writer might employ an exclamation point. Without that brilliance, whatever statement the composer wishes to make is truncated.

Also on the Rachmaninoff, winds lacked the richness I've come to treasure, and horns their cutting edge brilliance. The overall presentation was rather flat. As I said, it was neutral to a fault, characteristic of good transistor electronics. This may be exactly the sound PS Audio is after, and a sound that many who prefer solid state search for. But it does not make me want to stand up and shout. I like the lush midrange that tubes are famous for, a lushness resulting from even-ordered harmonics.

Vocals

It is no secret that vocal music is my first love. One night, we were watching a VAI DVD of Master Classes taught by the great soprano Lotte Lehmann when she was around 73 years old. Mostly talking, occasionally singing an octave lower than she would have in her prime, Lehmann demonstrated subtleties of interpretation.

On one Schubert song, "Die liebe Farbe" from Die Schne Mllerin, Lehmann's pinpointing of syllables and words seemed quite exaggerated. Wondering if she actually sang the song this way during her career, I turned to the only recording she made of the song, set down 20 years earlier. I was stunned to find the interpretation far more choppy than I had remembered it from the last time I had listened. For the first time, Lehmann at times seemed more concerned with enunciation than singing, interrupting the flow of Schubert's line time after time as she underscored the meaning of words.

What is going on here, I asked? This is not the Lehmann I have grown to love after 40 years (yes, 40) of listening to her singing.

Playing the same recording using my reference tube amp, I heard the Lehmann of old. Yes, the words were unusually clear, consonants and syllables voiced with great concern for meaning. But there was also a beautiful singing flow to the performance, a ring to her aging but still incomparable voice that marked a rendition of consummate musicality.

I also noticed many slight gradations of volume and vocal shading, all of which riveted my attention. At one point, Lehmann strove to sing softly where soft tones were no longer easily achieved, the voice taking on an extra edge that spoke volumes. The performance was riveting.

Returning to the PS Audio, I noted that while these details were still audible, they meant far less to me in the context of an overall presentation devoid of treble brilliance. The judicious use of shading and nuance that defines one aspect of interpreted greatness went for less with an amp whose sound was more notable for grayness than brilliance. Again, it is the tube sound reproduction that is responsible here. Neutrality is not revered by everyone.

System Synergy is the Key

A month later, Theta recalled its greatly appreciated long-term loan Carmen II transport. (John Baloff, you deserve a Gold Star on the Audiophile Walk of Fame.) Returning to my former reference transport, a Sony professional model heavily modified by APL, I noted less emphasis and fullness in the lower midrange and on bottom, and a corresponding diminution of brilliance on top. The sound on top did not seem any less extended, but it lacked the natural sheen of a live, resonant space. Clearly the Carmen II sounds as good as it does because its upper frequency brilliance is balanced by a strong midrange and bottom. The APL transport is leaner and less attention-getting by comparison, but no less musical.

Returning to the Lehmann performance, I found that while the differences between GCA and reference tube amplification remained significant, the APL transport's less Technicolor presentation lessened the ultimate musical consequence of the difference between amps.

This leads me to reflect that choice of source components will have a lot to do with how much you like this amp. The GCA will probably sound best with a CD player and/or preamplifier that tend to be bright. You could also pair it with a tube preamplifier to get some of that midrange lushness, but not have too much (for some consumers) lushness that you might have with an all tube setup.

More Listening

Using the Sony/APL transport, I also listened to the startling new recording of Osvaldo Golijov's Ayre (DG), featuring the incredible soprano Dawn Upshaw supported by The Andalucian Dogs on acoustic instruments and laptop (CD review forthcoming). Anyone who loves classical, world, South American, Sephardic, or new music owes it to themselves to hear this fabulous recording.

On track 3, where electronics play a strong part, I found the sound less vibrant than I would have wished. This was also true of Track 11. It was as though I was listening through a gray window that needed to be scrubbed clean. Highs lacked shine, and I found myself less intrigued than usual by the sinewy excursions of Dawn Upshaw's amazing voice.

To compensate, bass was ample and solid, the soundstage full, and there was a nice amount of air around voice and instruments. Regardless, I cannot say I was fully engaged by the performance.

Putting Matters in Perspective

I recently attended a Bay Area Audiophile Society (BAAS) audition of a new member's system. The system was located in a relatively narrow living room where nearfield listening was the only option.

Despite owning an integrated tube amp from a company whose preamp I consider one of the finest I've reviewed, I found the system absolutely flat sounding, harsh to point of irritation, bass shy, and lacking the midrange warmth one would expect from tube amplification. A few important changes removing a stock power cable and placing the Marigo Signature 3-D Mat atop CDs tamed highs, dramatically improved midrange and bass, and introduced some much-needed air and depth. Everyone present heard the changes; the host readily agreed that my suggestions had made a major difference.

Nonetheless, I can hardly say that I enjoyed my time with the system. I spent the last 20 minutes of our hour-long audition variously eating food in the next room while listening through an archway, and talking in the kitchen with a wife of a just-arrived member who said she could never sit in the same room as any supposed high-end system she had yet encountered because the sound was too bright. I'm sure this system did not change her opinion.

I imagine that the GCA-250 would have provided near ideal amplification for this setup. Its tonal balance is exactly what the system needed.

At Ashkenaz, a well-known club in Berkeley that recently hosted kora master Mamadou Diabate - where with the GCA-250 playing Diabate's beautiful disc Behmanka (World Village) in the review system at home, I can hear the treble delicacy of the kora's strings - I instead heard a monstrously overblown midrange and an unnaturally amplified bass "thwah" from thumbs on strings overwhelm the leading treble edge of the tone. I thought I had encountered the kora from hell. The sound was awful.

I finally approached the soundperson way in the back of the room, where bass resonance was dramatically truncated, to ask if he had any idea what it sounded like upfront where the audience was seated. It turned out that he didn't have a clue. I left the concert in intermission, lamenting that those in the audience had next to no idea how beautiful the kora can sound when amplified properly.

I have discovered that most people raised on poorly amplified sound as opposed to acoustic performance in live venues have lost their reference for what music can and should really sound like. As a result, many systems are way out in left or right field, producing highly distorted, overblown, one-dimensional sound. Depending upon what you're used to hearing, and how your system is tuned, the tonal balance of the PS Audio GCA-250 may be exactly what you need.

Note

Paul has told me that the amp takes a very long time to break in and said that he had burned it in before sending, "but as soon as it's unplugged and sits for a while, you have to start over. This happens to be more sensitive than just about any piece of gear I've ever designed."

This is not mentioned on the website or in the instruction manual, so you should take it into account when using the product.

Conclusions

The GCA-250 has much going for it: excellent, tight bass, beautifully controlled; well-nuanced lower midrange with pitches very well defined; a midrange of enviable neutrality; a large soundstage in which instruments are clearly placed and conveyed with excellent focus and detail; a credible amount of air; and silent, relatively cool operation that consumes low energy at idle.

As with any amplifier, satisfaction depends upon careful component matching. In my particular case, front-end components that were already highly tuned to each other and relatively neutral in tonal balance did not prove the best match for an amp that tends to favor bass and midrange over highs. In a far brighter system I recently auditioned, I'm convinced the GCA-250 would have proven near ideal. If your system sounds like it would benefit from the GCA-250, you can try it free for 30 days.

 

- Jason Victor Serinus -

REFERENCE SYSTEM

Digital Front End
Theta Gen VIII DAC/Preamp
Theta Carmen II transport (on loan from Theta)

Amplification
Jadis DA-7 Luxe with GE 5751 Jan and Jan Philips 5814A tubes

Loudspeakers
Talon Khorus X speakers MK. II (with latest modifications and Bybee filters on woofers and tweeters)
Rocket UFW-10 subwoofer

Cabling
Nordost Valhalla single-ended and balanced interconnects
Nordost Valhalla balanced digital interconnects
Nordost Valhalla bi-wired speaker cable
Nordost Silver Shadow digital interconnect for DVD-V
Nordost Valhalla Power Cables
Elrod EPS-2 Signature
AudioPrism SuperNatural S2

Also on hand and sometimes used:
Interconnects: WireWorld Gold Eclipse 5 and Gold Starlight 5 digital, Harmonic Tech Magic One, Acoustic Zen Silver Reference II balanced, and Nirvana BNC-terminated digital.
Power cables: Elrod EPS Signature 2 and 3 plus EPS 1, 2, and 3; WireWorld Silver Electra 5, PS Audio X-treme Statement, Harmonic Tech.

Accessories
PS Audio P600 Power Plant power synthesizer with MultiWave II
ExactPower EP15A (for subwoofer)
PS Audio Ultimate Outlet; PS Audio Power Ports
Ganymede ball bearing supports under all components and speakers
Michael Green Deluxe Ultrarack, Basic Racks and Corner Tunes
Shakti stones on amp, Theta, and transport
Stillpoints ERS EMI/RFI sheets on most components
Bedini Dual Beam Ultraclarifier, Audioprism CD Stoplight,
Marigo Signature Mat for use atop CDs, Ayre demagnetizing CD and the original Sheffield/XLO demagnetizing and break-in CD.

Room Size
25.5' deep, 37' wide opposite the speakers, 21.5' wide in the listening area. Ceilings are 9'2" high with heavy wooden cross-beams. Floors hardwood and carpet. Walls are a combination of plaster and wood. There is a large archway opening next to the right speaker.

Copyright 2005 Secrets of Home Theater & High Fidelity

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