PS Audio 200C power amplifier J. Gordon Holt
PS Audio's most ambitious product to date, this hefty power amplifier combines no-holds-barred construction and an attention to detail which borders on the neurotic/compulsive.
For instance, the interconnections between the output devices and the speaker terminals are machined and formed from a 1/8" sheet of copper, to provide a very low resistance conduction path between the output devices and loudspeaker terminals. This allows the speakers to draw on every joule of energy stored in a pair of 10,000µF storage capacitors.
According to PS, the 200C is the first audio component ever to use gold-plated speaker-protection fuses. They contend that oxidation at the contacts of "conventional" (nickel-plated) speaker fuses causes distortion, not an unreasonable claim given the low impedance of a loudspeaker line. (The lower a circuit's impedance, the more effect a given amount of resistance will have.) But PS carries this idea even further by including their gold-plated speaker fuses inside the amplifier's feedback loop, to take care of the fuse's residual distortion, which PS claims to be inherent in all fusible conductors. Now, that's what I call overkill!
PS also claims first use of solid-copper output transistors. That this is patently impossible (there's gotta be room inside for the semiconductor device!) suggests only that PS should come up with a clearer way to explain that each output transistor's outer case is made of copper. The supplied literature fails to make clear what advantage might be gained from a solid copper transistor, except to imply that it improves the coupling of power and extraneous heat to the solid copper output straps (probably true).
The entire circuit path is direct-coupled, and will amplify any DC input voltage by a factor of 30 if given the chance. Since this could obviously damage or destroy the system's woofers, an alternative capacitor-coupled input is provided, for use with preamps whose outputs have DC offset. (PS's manual points out that any preamp having DC at its outputs is defective, and that repairing it makes more sense than compensating for the defect with an in-circuit capacitor, which inevitably produces some loss of signal quality. Good advice.)
Incidentally, PS's manual for the 200C has one glaring omission: specifications. None at all (the ones in this report were gleaned from Audio's equipment directory). Okay, so I can understand a manufacturer taking the view that specs are less important than the way a product sounds, particularly in the case of an amplifier whose distortion figures are mediocre by high-end standards, but there are certain specs which must be known in order to properly utilize an amplifier. Input sensitivity, for example, to determine how the amp will balance out in a biamplified system, or power consumption, for computing the per-month cost of following PS's recommendation to leave the amp on continuously, or input impedance, to figure how to set the impedance switch on a passive crossover network. (For the 200C, these figures are: 1.25 volts, about 100 watts no-signal, and 100k-ohms.)
The 200C uses no protection circuitry as such. Instead, it uses a combination of fusing and thermal sensors to protect the amplifier and the speakers. The speaker fuses will blow instantly if the system gets a sudden massive overload—preferably blowing before the loudspeakers do. The fuses provided are 8-amp fast-blows, which will not protect a speaker of modest power-handling capacity. It will take over 200 watts into a 4-ohm load to blow an 8-amp fuse, and almost 350 into an 8-ohm load; watch it! The thermal sensors respond to the kind of marginal overload condition, which causes the amp to overheat, and will eventually trigger the amplifier's power relay to open up.
This relay, by the way, makes a most alarming zap sound and a bright flash when you first turn the amp on. This is normal, but it takes some getting used to. If you've just recently turned the amp off, you don't get the flash on turn-on, since the capacitors haven't yet discharged.
I let the 200C warm up for 24 hours before taking my first listen, so I can't report how bad it may have sounded right out of the box. My experience, though, has been that no amplifier sounds as good immediately after a one-week hiatus as it does after at least an hour's warmup or, for solid-state equipment, 24 hours. PS, like most other high-end manufacturers, recommends leaving the 200C on at all times. I would qualify that by recommending that it be unplugged during thunderstorms, and while you're away for more than a day or so.
I tried the 200C on two speaker systems: The Infinity RS-1B and the Martin-Logan Monoliths, both of which I am very familiar with. The RS-1Bs must be biamplified, so I had to audition the 200C in two shifts. The Monoliths can be biamped, but since I am more familiar with their characteristics with the amp run full-range, that's the way I used this amp. Other equipment included a modified Revox A-77-II playing 7½ and 15ips 2-track tapes and a Kyocera DA-910 CD player with a variety of audiophile fare (Sheffields, Reference Recordings, Opus 3s, and a few Telarcs). No preamp or analog discs were used because my reference Conrad Johnson Premier Three preamp was at the factory for a checkout; it has so spoiled me that I'd rather do without than use another preamp.
The PS 200C is only the second solid-state amplifier whose extreme high end can be favorably compared with the best I have heard from tubes, the other being the Rowland Research 7. Neither has quite the exquisite sweetness of, say, the C-J Premier Five, being instead a hair on the dry side. But there is not a trace of grain, grit, or tizziness in the 200C's high end, making it one of only two solid-state amplifiers I would recommend for use with electrostatic systems. High-end quality has not been the strongest suit with PS Audio's previous power amps; but it is one of the 200C's strongest, though the Rowlands still surpass it by a small margin, mainly in terms of completely unstrained openness and sweetness. Of course, the Rowlands, cost $6500 a pair; I've never heard this kind of high-end sound from an amplifier in the 200C's price range.
This is one of the most neutral-sounding power amps I know of. The mid/upper middle range is neither forward-sounding like tubes nor recessed like many solid-state amplifiers. It is not quite as forward as the Electron Kinetics Eagle 2 and not quite as laid-back as the BEL 2002. Inner detailing and resolution of delicate nuances are excellent, soundstage width is very well rendered, and depth and perspective are well presented, though not as well as from the best tubed amplifiers.
Bass is excellent: deep, tight, and very well-controlled, but not quite as taut as that from either the Eagle 2 or the Adcom GFA-555. (This is not to say that either of the others will do a better job of reproducing low end on all loudspeakers. They do best with rather underdamped speakers that need what might even be an overly taut low end; the PS does better with speakers that have very good damping characteristics to begin with. For instance, on the M-L Monoliths, the Eagle 2 produced much tighter bass than the PS; on the RS-1B woofer columns, it was hard to tell the Eagle from the PS except at very high listening levels, where the 140W Eagle was obviously going into clipping while the 200C sailed along.
Apart from the slightly compressed depth, the only area where the 200C was judged to be inferior to the best of the competition was through the upper middle range, where a very subtle texturing detracted slightly from the system's "ease" of listening through the Monoliths. I did not notice anything amiss here from the Infinity RS-1Bs, which are more-than-normally revealing. (The Monoliths, like all electrostatics, are exceedingly revealing of such things.)
Here, then, is an amplifier that can hold its own, overall, with anything else in its price class; it will work best with speakers that are neutral through the middle range, very extended and detailed at the extreme top, less than microscopically revealing through the middle range, and well-damped through the low end. And, since it will cleanly belt out prodigious amounts of power, the PS 200C should be ideal for "difficult" loads like full-range ribbon speakers and dynamic systems with complex crossover networks.
This is, if not a world-beater, at least a world-class amplifier, far better than PS's previous amplifiers—not to mention just about all the competition. While not cheap, it's a lot less than many people have been paying for amplifiers that aren't nearly as good.—J. Gordon Holt