Tube Preamp Reviews

How important is the use of balanced circuit typology in the design of preamplifiers and power amplifiers? Ask the top audio designers (I didn't, but just play along, okay?) and you'll get a wide variety of opinions. Some reject the balanced approach outright, arguing that it represents a needless duplication of circuit components, and that better results can be achieved if the same attention and resources are devoted to perfecting a single-ended circuit. In his provocatively titled article "Balance: Benefit or Bluff?" (Stereophile, November 1994, p.77), Martin Colloms questioned the advantages of balanced designs, suggesting that while the results may be better in certain respects (eg, noise level), the reproduced sound may suffer in other, perhaps more important ways (eg, rhythm and dynamics).

I had been sent a sample of the Woodside SC26 tube preamplifier during my June 1994 review of Woodside's MA50 monoblock amplifier (Vol.17 No.6). Although I used a number of preamplifiers during that review, I was most impressed with the MA50s' spacious, three-dimensional soundstage when driven by the SC26. At the time, I had an impression that the SC26's sonics combined a midrange richness with a good dynamic range. Although I had to return the Woodside MA50s to the importer after I reviewed them, I continued listening to the SC26.

Last September, in Vol.15 No.9, I started my quest for the Ultimate Kilobuck Tube Amp with reviews of the $995 Panor/Dynaco ST70-II and the $1695 Nobis Cantabile. While neither really fit the bill—the Dynaco fell a bit short in terms of sonics, while the Nobis was priced a bit higher than a thou—they got me thinking of the Ultimate Kilobuck Tube Preamp. Because the greatest amp in the world can only sound as good as whatever drives it, and there's no sense looking for a kick-ass affordable tube amp if you're going to play Scrooge McDuck when it comes to the preamplifier.

"I remember Momma!"

Conrad-Johnson launched the all-tube Premier 7 in 1988 as an all-out sonic assault on the state of the preamplifier art. A great deal has happened since then. For starters, C-J has gotten a great deal of feedback from customers, dealers, and reviewers. None other than J. Gordon Holt (Stereophile, November 1988, Vol.11 No.11) concluded that: "It appears that nothing which could possibly have improved its sound had been omitted....It is, in fact, about as close as any tubed preamp has come to being perfectly neutral in sound—in nearly all respects." In the now-defunct Sounds Like... (issue 3), Sam Burstein concluded that "It is, with certain reservations, absolutely delightful to one's musical senses." And, speaking of absolutes, even Harry Pearson gave the Premier 7 a rave in the first round of his preamplifier survey (TAS, issue 58). As icing on the cake, John Atkinson (Stereophile, Vol.12 No.8) concluded that the 7 had "the requisite degree of sonic magic to make it a Class A recommended preamplifier."

A "CD processor," is how I distinctly heard Cary Audio's Dennis Had describe it. The venue was Stereophile's High End Hi-Fi Show in New York last April. Nothing really unusual in today's digital marketplace, I thought to myself, though a bit out of character for a company dedicated to vacuum-tube technology. But wait a minute. Dennis had described it as an analog CD processor. Analog!? Well, yes, the unit processes the analog signal from a CD player.