Solid State Power Amp Reviews

"That's true. But Lars has a KSA-250. So does The Brass Ear. Since they've spent the money, I don't have to."

I can understand why Victor toots his own horn.

There is no cult—or camp—of C. Victor Campos. No Campos brand of electronics. No "Signature Editions." No Campos camp followers. I've never heard anyone say, "Gee, Victor Campos has designed a new amp. I gotta have it."

Mario knows of Victor, though.

"Oh yeah, C. Victor Campos," said Mario, scratching his chin. "He used to be the chief engineer for a New York City radio station. Never met him. Wild man, from everything I hear."

"That's the guy," I said.

The Adcom GFA-565 is a mono amp, the same size as a stereo chassis GFA-555. It is available in standard version for $1700/pair and $1900 with balanced inputs. Victor wanted to know if I wanted my amps with fans installed, which costs $200/pair extra, but I told him I didn't think I needed a blow job.

Each amp is rated at 300Wpc into 8 ohms, 450Wpc into 4 ohms, and 850Wpc into 2 ohms—a bargain, wattwise. My favorite measurement of value for an amplifier is cost per pound. On the basis of last October's Audio annual directory issue, a Krell KSA-250 costs $39.86 per pound—not bad, actually. A B&K M-200 monoblock costs $22.45 per pound. Good deal. An Adcom GFA-565 mono is a mere $19.31 per pound, which isn't much more than I paid yesterday for some particularly fine salmon fillets.

I find the Adcom amps plain, but handsome (footnote 1). Heatsinks are in the back and hardly ever got more than mildly warm. Terminals are provided for two pairs of speakers, but no switching. This is handy for bi-wiring. The terminals are inconveniently recessed between the heatsinks, which might be a problem with some cables. Rail fuses and main AC fuse are conveniently located on the back—no need to open the chassis. On the balanced version, a switch lets you switch between balanced and unbalanced. Also in balanced mode, you can change the input sensitivity of the amps, but this is probably of interest more to professional users. The AC line cord is hard-wired, sparing you the temptation to experiment with $200/pair accessory power cords.

"We've had little demand for the balanced version," Victor told me. Undoubtedly because Adcom hadn't made it available.

"Wait. I'll stir up trouble. I think balanced is better. It was with the B&Ks. How about a balanced Adcom preamp to go with it?

"We don't have one."

"It says in your ads that you do."

"We haven't had any great demand."

"I think you're going to get it now."

"Do you have to make life difficult, Tellig?"

"Do you have to ask, Victor?"

I used a balanced, 25' run of AudioQuest Quartz Hyperlitz from the B&K Sonata Pro 10 balanced preamp to the mono Adcoms. If Adcom won't sell you a balanced preamp, B&K cheerfully will. (Now that ought to get Adcom geared up for balanced preamp production!) CD transport was a Philips CD60 into a Meridian 203 processor. AR ES-1 turntable with SME 309 arm and various cartridges, mainly the Kiseki Blue Gold. Spendor S100 speakers, of course.

The first thing I noticed, right off, even with the amps cold, was that the bass was deeper, tauter, tighter than with the B&K monos. This is what these British speakers like: a proper American amp to grab 'em by the balls and lift 'em in the air. The Spendors can sound a wee bit heavy, even soggy, with certain amps—the VTL 225s, for instance. Not these. The Adcoms take the Spendors and make them fly. Big speakers, with satisfying bass, the Spendors actually sounded fleet of foot with the Adcom amps.

Not that the B&K M-200 monos are slouches on the Spendors. I found that the B&Ks produced reasonably tight, well-articulated, but not especially ample bass. Remember? I complained about that earlier. The Adcoms do much better in the bass, having a balls-to-the-wall quality that comes close, very close, to the Krell KSA-250, which is probably the last word when it comes to cojones.

Two days into listening, Victor called again to put ideas in my ears.

"A characteristic of high-powered amps," lectured Victor, "is that they have tended to lack detail and resolution of low-level information. We designed the GFA-565s to have low-level resolution which compares with the best of the best."

I told you in an earlier column that the B&K M-200 monoblocks have "transparency in spades." This is true. What makes things awkward for me now is that the Adcoms have even more—at least in my system, with my Spendors.

The Adcom sounds neutral. The midrange and treble are exceptionally smooth for solid-state, but just a tad less sweet than the B&Ks. But the biggest difference is that the Adcoms sound more powerful. Indeed, by the wattage ratings, they are more powerful: 300Wpc vs 200.

"I bought a lot of speakers when I designed the GFA-565s," Victor said, and added, "I destroyed most of them." Not that you're likely to do so unless you're reckless. But beware: these are extremely powerful amps and the potential for speaker damage is quite real, especially if you do something dumb like remove an RCA plug while the amps are powering your speakers!

Detail is excellent. With the Adcoms, I can hear separate instruments, even to a greater extent than with the B&Ks. What's more, these instruments were even more precisely localized and their position seemed to stay stable. With the B&Ks, the sound, particularly of a symphony orchestra, was spacious, but more diffuse, more blended, less defined than the very precise sound of the Adcoms.

So, the Adcoms are "better" than the B&Ks, right? Not so fast. The B&Ks strike me as more tubelike than the Adcoms, in almost every sense. The sound is round, blended—dimensional. The Adcoms, while not sterile, are lean, clean, and very tight in the low end. The B&Ks simply did not dig down with the gusto that the Adcoms could muster on my Spendors.

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Footnote 1: The amps are available in black or white, by the way, but I wouldn't recommend the white: tends to discolor unless kept scrupulously clean.