Infinity Servo-Statik 1 loudspeaker J. Gordon Holt October 1975
For the benefit of readers who missed our last issue, this speaker system and the FMI J-Modular (see p.4 in this issue) are, in our judgement, the most accurate loudspeakers currently available, bar none. The SS-1A is substantially more costly—more than twice so—and must be biamplified. (The biamping is for the mid and high-range electrostatics; the 18" woofer is driven by its own 150W solid-state amplifier.) The FMI can be driven by a single amp. And then there is the question of dependability.
As we mentioned last time, our sample SS-1A was pre-production, and a few parts therein failed during the first couple of weeks of use. (As did just about everything this summer!) That, plus the bad reputation gained by the previous-model Servo-Statik (the SS-1) and some persistent reports of continuing problems with midrange speaker modules, has made many buyers leary of getting committed to the tune of $4000+ with an SS-1A. So we should report that, as of now, our SS-1A has been working without a falter for three months, which is a good sign.
Experience has shown that, if a component is going to fail, it will usually do so within the first week of operation, occasionally within the first month, and rarely after that until several years have elapsed. Nonetheless, indications are that breakdowns of midrange panels in new SS-1As are still rather more common than they should be, so the system may not yet have been debugged.
It is, however, inevitable that an electrostatic will be less dependable in the long run than a typical speaker system, simply because it is at the short end of the laws of probability. It has far more component parts than a conventional system, and many of them operate at high voltages, both of which factors increase the probability of trouble. High voltage alone is not necessarily a liability, as witness the millions of neon signs in the US that are still working after 10 or more years.
We have not, as a matter of fact, heard of a single power-supply breakdown in any production-model Servo-Statik 1A system.) If a problem does develop in an SS-1A, it is more likely to be in the system's—electronic crossover unit, which has far more parts although operating at lower voltages. Most of the circuitry in the crossover is on plug-in boards, so a reasonably adept audiophile could install a new one without having to pay his dealer for repair service.
We suppose what the dependability question all boils down to is: Is it worth the higher risk of a component failure to enjoy the best possible sound when the system is working? The answer to that will depend on just how high that risk actually is, which is something that cannot be determined until the SS-1A has been around for a few years.
One of the odd things we have observed for many years but have tried not to think too much about is how it is possible for two top-rated speaker systems to sound so different. The implication thereof would seem to be that one of them is "right" and the other "wrong," or—worse—that both are wrong. It now begins to look as though the third conclusion was the correct one, for not only are the SS-1A and the FMI J-Modular better—ie, more natural—reproducers than any systems we have heard previously, they are more alike. The fact that they still don't sound the sane raises the same old question, but their similarity—under certain conditions which we'll mention subsequently—suggests that the Holy Grail of high fidelity, Ultimate Perfection, may not be all that far over the horizon.
Before we go into any further detail about the sound of the SS-1A, a word about associated components. In our last issue, we climbed out on a limb with the statement that the best possible reproduction of sound today was from the best tubed components. The SS-1A was one of the speakers that led us to that conclusion. We tried every solid-state amplifier in the house, including Infinity's own class-D switching amplifier, as driving amps for the tweeters and midrange panels of the SS-1A, and among the four pairs of educated ears that collaborate on our listen-ins, all felt the tubed amplifiers did the best job of reproducing that exceedingly delicate balance between sweetness and sharpness that is the sound of live music.
We tried Ampzilla, the Dyna Stereo 400, the Epicure One, Infinity's amp, and the tubed Audio Research D-76A and Paoli 60M. We listened to original tapes made with a variety of mikes and in different acoustical environments, we listened to domestic and imported discs and open-reel tapes, and tried a few experiments involving trying to reproduce the sound of a speaking voice and comparing it with the person standing midway between the speakers. The D-76A won every time, driving both the middle-range and tweeter panels.
The same held true for the preamp. The solid-state units we tried—the Dyna PAT-5, Mark Levinson JC-2, and a couple of preproduction prototypes on hand—were marginally better than the Audio Research SP3A-1 in a couple of ways (different ways for different preamps), but the ARC still maintained more of that delicate musical balance, and the liquidity and roundness, of live music than did any of the others.
What we are driving at is, if you are going to spend $4000 for an SS-1A, be prepared to spend whatever it will cost you to mate it with the finest tube electronics available. As of now, that means Audio Research, but the picture may change in the future. As a matter of fact, the future may even bring a solid-state amplifier that can beat the ARC's musicality, but for the nonce, the only amplifier that comes close (and has better high end, to boot) is Infinity's switching amp. We still prefer ARC on the middle range, and have mixed feelings about it on the top, but if you need more volume than a pair of D-76As can deliver (up to 105dB cleanly in a 13' by 21' room), for reasons of a larger room or a lust for violence, the Infinity SWAMP is the only other one we recommend. (If you only have one SWAMP on hand, use it on the midrange. It will do fine on the tweeters, but they don't really need more than 50 watts, although they are rated at up to 125.) If cost is any consideration—and it shouldn't be if you can afford the SS-1A to begin with—alternate choices for hiqh-end drivers are the Paolis, a modified Dyna Stereo 70, a Quad 303, and an unmodified Stereo 70, in that order.
Unfortunately, many Infinity dealers are not also Audio Research dealers, which means you may not be able to hear an SS-1A performing at its best in a dealer demo. Many dealers use Ampzilla to drive the tweeters, and while Ampzilla has as sweet a high end as any conventional (ie, non-switching, non-FET) solid-state amplifier, it is appreciably harder and drier at the top than a D-76A, and it will not do justice to the system. If your dealer doesn't have ARC stuff and won't let you take an SS-1A home on approval, you'll just have to take our word for how lovely that high end can be!