Solid State Power Amp Reviews

J. Gordon Holt, October 1990 (Vol.13 No.10):

Editor's note: In this year's January issue (Vol.13 No.1), Robert Harley reviewed the Carver Silver Seven-t monoblock power amplifier and was not impressed with its sound. Yet just one month earlier, in his December 1989 "Final Word" column, Larry Archibald had reported that the Silver Seven-t had produced a good sound when used to drive the midrange/tweeter panels of the Infinity IRS Beta loudspeaker system. In view of this disparity of opinion, I had appended a footnote to RH's January review—"I feel a 'Followup' is definitely in order"—and had accordingly arranged for the pair of SS-t amplifiers auditioned by LA (serial numbers 00228 and 00302) to be shipped to J. Gordon Holt.

Unfortunately, one of the pair (00228) was lost in transit, delaying JGH's "Follow-Up" review until Carver Corporation could ship a second pair of amplifiers to him. The serial numbers of the new pair were 00428 and 00490, the same as the pair that RH had reviewed and that had appeared to go unstable on the test bench when driving a 2 ohm load at very high levels. Tamara Barratt of Carver had told LA that these two amps were the same ones RH had listened to, but she was unclear as to whether they had been repaired. I therefore carried out a set of measurements on one of these amplifiers after JGH had finished his auditioning to determine, among other things, that it was functioning correctly. So, without any more ado, what was Gordon's impression of the Carver Silver Seven-t's sound, a sound that has been said by Bob Carver to "virtually replicate" that of his $17,500 Carver Silver Seven tube amplifier?—John Atkinson

JGH reports: Personally, I think LA was closer to being right about this amp than RH, who heard from it "no redeeming sonic virtues." I disagree; I heard several. On the other hand, I don't think it sounds "just like a tubed amplifier," because there is no such thing as "a" tubed amplifier. There are lots of them, and no two sound alike. But most of them do tend to share certain sonic earmarks: a slightly warm, rich low end with only moderate detail and impact, a rather forward, bright (some would say overbright or "glassy") midrange, and a high end that is either silky-smooth and musical if your speakers have superb top, or dull and lifeless if they don't. Tubed amps tend to reproduce depth very well, and in the opinion of many people whose judgment I trust (I'm one of them), they tend to produce a stronger impression of listening to real (acoustical) instruments than most solid-state amplifiers, which are often more analytical than euphonic. Well, I hear a number of those tubey traits from the Silver Seven-ts, but not all of them.

On first listen, after an hour or two of warmup, I was passionately in the RH camp. The Seven-ts sounded awful—coarse-grained, congested, and completely flat, with bass that had all the impact of a wet sock. (And I do not mean the kind of sock you feel in the pit of your stomach; that they did not have.) I wondered whether LA wasn't getting soft between the cochleae.

After four hours more of cooking, I began to think they were sounding a little less awful, but I wasn't sure. So I gave them four days before the next listen.

Transformation!!!

I cannot recall when I have heard this much improvement from any electronic product as the result of nothing more than a prolonged simmer. (Actually, an inappropriate word here; the Silver Seven-t runs ridiculously cool.) They still did not have the bass of a Krell or the highs of a Levinson, but then neither does any tubed amplifier, and that's what I believe these are supposed to sound like. They did, however, have much of the best tube amps' midrange authority and aliveness and high-end sweetness, and I soon found myself—rather to my surprise, after what RH's review had led me to expect—actually enjoying music (and Laserdisc soundtracks) through them. Lower middles through my Sound-Lab A-3 electrostatics had a weight and gutsiness I have not heard from that speaker before, and I liked it.

Inner detailing was very good but not superb, and—as is to be expected from totally isolated power supplies—the soundstage was very wide, with the capability of good beyond-the-speakers imaging. But the soundstage was not very deep, even in comparison with my pair of VTL M300s, which are just as forward-sounding (if not more so). Highs were just a touch dry, with some (but not all) of the wispy delicacy of real music, but the low end was a disappointment.

I have come through the years to associate high power with deep, tautly controlled lows in which you feel you can "count the cycles" from an open-string bowed double bass. The Carvers did not do this. Although they were easily capable of bottoming-out my speakers on Telarc-style bass (footnote 1), they did not have much impact or pitch delineation at the low end. They were not, however, remotely thin-sounding; if anything, the bass was a little on the heavy side, just as it is with most tubed amps.

Most top solid-state power amplifiers sound (to me) just a little bit withdrawn through the midrange, as though their frequency response is very slightly dished-down in the middle (although none ever measures that way). The Carver does not. It is less forwardly bright ("alive") than my VTLs, but there is no way I would describe it as being "thin," "shrill," "hard," or any of those other nasty terms which add up to unlistenable. Why, then, did RH find them to be so?

Assuming this isn't another case of sample-to-sample variation (which I doubt, as my two samples were audibly perfectly matched), I think it was the speakers Bob was using for his review. While I never heard the MartinLogan Sequel IIs in New Mexico, I did hear them on several occasions at a friend's house in Denver. I never cared for them, largely because they sounded (with the amps we had on hand) almost exactly the way Bob described the Carvers as sounding. Those Sequel IIs were, in fact, the first loudspeakers I've heard that sounded excruciatingly strident with my VTL 300s. (The VTLs do not have the usual tube-amplifier warmth and richness; they are very close to being absolutely neutral in "color." The VTLs sounded gorgeous with the Betas when I was testing those speakers; LA felt the Carvers did very well with Betas, too.)

I haven't heard the $17,500 Carver Silver Seven tube amplifier, so I can't compare the SS-t with it. But I do feel RH came down too hard on its solid-state cousin, for subjective flaws which I conjecture may have had more to do with his loudspeakers than with the amplifier. $1000 a pop isn't all that cheap, but when it comes to dollars per watt, there's nothing else I know of that comes even close to the Seven-ts. (The dbx BX-3 is claimed to deliver 400Wpc for $1299, but it's hard to find. Most dealers will tell you dbx got out of consumer electronics two years ago, but they didn't. Only some products were discontinued.)

In other words, the Silver Seven-t is not to be lightly dismissed—certainly not as peremptorily as Bob cast it into the outer darkness. It does some things very well, it is very neutral through the all-important midrange, and it has as much power as amps costing more than $4000 each. As I see it, these "redeeming" features help to offset the fact that the Seven-t is not the suavest-sounding amp you can find. But for that price, even at 50Wpc, what is?

Carver's Silver Seven-t amplifier is recommended, with reservations.—J. Gordon Holt

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Footnote 1: In fact, they did it more often than they should have, apparently because of their relative lack of overshoot control.