Counterpoint SA-100 power amplifier

The $1200 Counterpoint SA-100 amplifier came up to bat fourth in my listening sessions, behind (in order of appearance) the Adcom GFA-555 II (not reviewed here, but sent along by JA for comparison purposes), the VTL Tiny Triode monoblocks, and the Muse Model One Hundred. Thus, my progression went from bipolar solid-state to tube to MOSFET, with a wide spread of sonic characteristics between them: stygian bass from the Adcom; uncanny spatial presentation and vocal reproduction from the VTLs; and an overall superior sound from the Muse. I was therefore eager to see where the tube/MOSFET hybrid Counterpoint would fall in this group of very different-sounding amplifiers.

The external appearance of the SA-100 is conservative and simple, the brushed black (silver is also available) front panel simply carrying the on-off switch and the status LED; this last glows red at turn-on, green once all systems are go. It takes a full minute for the LED to change from green to red; as with traffic lights, this is one of the longer minutes you'll encounter. The back panel sports gold-plated binding posts and RCA jacks, as well as the nonremovable AC line cord. I have a problem with the size of this cord; 18ga cable may suffice for preamps and CD players (many designers would opt for a heavier gauge even with these line-level components), but I feel that the power-line cord of a power amplifier, especially one rated as powerful as the SA-100, should be larger for better current delivery to the power supply. In comparison, both the Adcom and Sumo Polaris have 16ga AC line cords, with half again as much conductor diameter. The Muse comes supplied with a hefty 10ga AC cable.

Removing the top cover revealed a most impressive interior; parts quality, layout, and construction were all superb. Wima metallized-polypropylene and Wonder caps, Resista metal-film resistors, and several small-value polystyrenes populate the circuit board. The main power supply consists of two rectifier bridges, one for each channel, smoothed by separate cap banks totaling 32,000µF per channel. Since both rectifier bridges are fed by the SA-100's single power transformer, I guess the power supply can't be considered dual-mono by those totalitarian separatists who insist upon complete isolation between channels, and frown upon using the same Q-tip to clean both ears.

An interesting aspect of the SA-100's design is the material used for its chassis: copper-plated steel. In the promotional literature and owner's manual, Counterpoint makes much of the contribution of this unique chassis material to the overall sound quality, due to the copper plating shorting out the current-induced hysteresis distortion of the steel. "Listeners report that a copper-plated chassis makes the bass tighter, offers increased transparency, and removes a 'dark overhang' that was clearly audible when compared against the same circuitry in a chassis of more conventional material," says Counterpoint's White Paper #2 with a straight face; I would have liked to hear two identical SA-100s, one with the copper/steel chassis and the other in a conventional all-steel or aluminum one in order to verify these claims; however, manufacturers such as Superphon and DNM have also spoken loudly of their special chassis materials as contributors to sound quality.

The Counterpoint's hybrid circuit uses two 6DJ8 dual-triodes per channel for its input and driver stages. The SA-100's tubes are Counterpoint's own selected parts; according to the owner's manual, every tube that leaves the factory in an amp or preamp has had over 200 hours of burn-in and 35 individual tests and measurements. As used in the SA-100, voltage amplification is derived from the two sections of a 6DJ8 configured in a cascaded common-cathode arrangement. Local feedback is used to improve linearity, and global feedback is returned to the cathode resistor from the first stage of the cathode-follower driver stage, this consisting of one section of the second 6DJ8, the other section serving as its current source. Counterpoint feels that using a section of the 6DJ8 as a current source achieves better linearity than the more common resistor-loaded topology. This driver section is AC-coupled to the output MOSFETs with 1µF Wima metallized-polypropylene caps.

The output section consists of two paralleled N-channel and P-channel MOSFETs per channel, biased for class-AB operation. Counterpoint states that these devices are biased to a very high standing current; I can definitely attest to this, as the amp ran extremely hot even during idle; with music material, the heatsinks were too hot to leave my hand on.

In the Counterpoint SA-100 we have a well-built circuit using selected tubes in a high-linearity topology for the delicate input and driver sections, right where we want tubes to be for their superior voltage amplification abilities; MOSFETs in the output section, devices that combine the sound of tubes with the current drive of solid-state, biased heavily into class-A; the finest passive components available in Wonder and Wima film caps and Resista high-quality resistors; heavy copper pcb traces, good layout, superb construction; and even the chassis is all-out, its copper-plated steel designed to improve the sound beyond that which the exact same circuit would achieve in a steel or aluminum box.

So why did it sound so bad?
I wasn't prepared for this. I mean, I was really expecting something special from the Counterpoint; everything about its design and construction points toward superlative sound. Counterpoint's flagship SA-4 amplifier has an excellent reputation, as do the various Counterpoint preamps. If ever a product had a background of sonic excellence, it was this one, but I absolutely could not believe how flawed the SA-100 sounded, from top to bottom. The amp had been left on continuously for a couple of days before I listened to it, but with no music playing; in order to give it the benefit of the doubt, I put the soundtrack to Superfly (footnote 1) on infinite repeat before leaving for work the next morning. When I came home that evening, I wiped my mental slate clean and listened to the Counterpoint again. No difference. Ten straight hours of "Freddy's Dead" and "Junkie Chase (Instrumental)" hadn't improved a thing besides my mailman's day.

Where to begin? The bass was boomy and distorted, with extremely poor pitch definition. The Counterpoint rendered the low end as a separate, disconnected entity from the rest of the music; without the bassline implying movement, music lacked the tension and release so vital to the emotional ebb and flow that must be there for my monkey bone (footnote 2) to vibrate.

The midrange was the least satisfying I have heard from any amplifier in a long time. Vocals came across as harsh and congested, with a throaty coloration apparent on both male and female voice. On the Trinity Session, Margo Timmins's ultra-clear voice sounded gravelly and dry, almost as if the Cowboy Junkies were suddenly fronted by Koko Taylor (footnote 3). The midrange and high end shared the most amusical characteristic of the SA-100: a hard spittiness that laid a halo of hash over everything. This was not a subtle effect; it rendered even my favorite discs unlistenable.

The high end of the Counterpoint was bright, grainy, and painful to listen to at any but the lowest volume levels. On the Ray Charles/Milt Jackson cut "How Long Blues" off the Soul CD (Atlantic Jazz 7-81708-2), Milt's vibes and Billy Mitchell's tenor are the only bright-sounding instruments on this slow, soulful blues; everything else is vintage Atlantic Ahmet'n'Nesuhi smooth. Brother Ray's piano (bless Tom Dowd, again) was miked from a good distance and sounded that way with the Muse. The Counterpoint added a tinkly quality to the piano that sounded very unnatural. In addition, Connie Kay's brushed hi-hat, normally very much in the background and softly rendered, became harsh and distracting. The effect was very similar to the infamous Aphex "Aural Exciter" (footnote 4) circuit so abused by many pop producers, and one which never fails to set my teeth grinding. I can listen to dull, sterile amps all day long, but the SA-100 was so irritating in so many different ways that I dreaded my sessions with it during the month and a half I had to evaluate it.

After swapping cables, lifting the ground pin, changing the AC polarity, changing the absolute polarity, anything to get it to sound decent, I decided to give the SA-100 my Ultimate Test; I lit the five blue candles in the shrine, said a silent prayer, and slowly placed Elvis's Sun Sessions (RCA CD 6414-2-R) into the player.

Most music-lovers have several records they call their favorites, in no particular order. Ask them to choose just one and they'll likely whine that it's impossible; how can you possibly choose between the Beatles and the Stones, Basie/Ellington, Muddy/Wolf, Monkees/Banana Splits? For me, there's no contest: *E*L*V*I*S*'S* *S*U*N* *S*E*S*S*I*O*N*S*. Everything else comes in a distant second. Suffice it to say, if any CD was going to sing to me through the Counterpoint, it was going to be Sun Sessions.

Oh my God in Heaven...
Bill Black's doghouse slap-bass sounded like a tuba along with someone playing the spoons on their knee, and Scotty Moore's guitar solos had a stridency I know isn't on the CD. But worst of all, Elvis's vocals became harsh and steely, with distorted sibilance and that throaty coloration I mentioned earlier. I still can't quite believe it even now, but for the first time ever, I couldn't listen much more than halfway through "Blue Moon of Kentucky"; the Counterpoint's time was definitely up.

Reading this review, one is mightily tempted to discount it outright; no amp could be that bad. Surely I exaggerate, perhaps put off sufficiently by one or two areas of weakness to dump on the whole spectrum of performance. Unfortunately, that's not the case here.

I'll leave a conditional opening here, as I find it hard to believe any established high-end manufacturer would let something this flawed out the door. I suspect that something is very much amiss inside this amplifier; if it's defective or broken in any way, then I would welcome the chance to hear a properly functioning unit. But if the amp I listened to represents a fully functioning SA-100, approved by Counterpoint as a sterling example of their line, then I can't possibly recommend it for music listening. Until I hear from Santa Fe or Vista that the SA-100 I listened to was defective, that's where I stand.

Footnote 1: Curtom Cur.2002-CD. One of my all-time favorites and probably not in stock at your local music emporium, so call Ichiban Records at (404) 926-9377 to order a copy. I paid $25 for the LP at a used-record store three years ago, but the Curtom CD sounds much better. On a sadder note, Superfly's composer, soul great Curtis Mayfield, was paralyzed by a falling lighting rig at a concert last year. He is reportedly doing well, but it looks like the paralysis is permanent.

Footnote 2: The monkey bone is the structure that encompasses the spine, skull, and hip-bone. As there is a wide variation among monkey-bone resonant frequencies between different people, so is there a wide variation in musical tastes. Some monkey bones sympathetically vibrate the strongest in the presence of classical music; my monkey bone has the letters R&B branded on the pelvis like a can of Mighty Dog.

Footnote 3: Now there's a visual...

Footnote 4: An Aphex "Aural Exciter" is, pure and simple, a distortion generator. It takes the incoming audio and generates a second signal comprised of low-order harmonic distortion, which is then mixed back with the original audio, the ratio of course being adjustable by the "Excitement" knob on the front panel. And they called Caligula mad.

Counterpoint Electronic Systems
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sugarrush71's picture

i own sa-100 and im very happy with it ...your review should start with statment that the unit might be defective cuz im sure that it was .

byyildirim's picture

I think that this review is totally misleading or something caused this. I have been very happy with counterpoint sa-100 for years. It is excellent as well as counterpoint sa-220. having listened any counterpoint amps anyone cannot say this is the worst amp if he or she has any kind of ear.