Tube Preamp Reviews

The lack of a mono A+B operating mode is, I feel, a significant shortcoming (albeit not a serious one); without it, the playback of mono recordings is compromised. (Mono A+B blending suppresses the distortion and surface noise arising from spurious vertical motions of the stylus.) I suppose the reasoning here is that no one who cares enough about sound to spend $8000 for a preamp is ever going to play old mono recordings, but most serious music lovers know that many definitive performances were recorded in mono, and they doggedly persist in listening to them occasionally. The Premier Seven will not serve them well in this regard.

I found the Premier Seven's phono section to have extremely low noise: negligible hum, only some very-low-level muted hiss. There was barely enough gain to allow the use of the extremely low-output Ortofon MC-3000, at moderate listening levels with the gain controls wide open, but the MC-2000 was beyond its capability, just as it has been with every other active preamp I've tried with the exception of the Vendetta Research SCP-2. It is obvious, though, that the Premier Seven will be able to handle practically any MC cartridge, and the 150mV phono overload spec would seem to ensure compatibility with any MM cartridge, too.

Spectrally, the phono stage was extremely neutral—more so than the line stages, inasmuch as it does not seem to thin out the low end at all. Nonetheless, the extreme bass range does not have quite the impact and extension of the John Curl-designed Vendetta. Again, definition was excellent, and soundstaging was not diminished in comparison with the line stages.

So far, then, the Premier Seven appears to be a definite contender for inclusion in the Class A category in Stereophile's "Recommended Components." But I have not taken its price into consideration. At a price approaching $8000, a preamplifier must be beyond reproach, both sonically and ergonomically. It should stand head and shoulders above any less-expensive competition.

How, then, does the Premier Seven stack up to that competition? Except for the slight low-end deficiency, the Seven is among the most neutral- and ingratiating-sounding preamps money can buy. The others are the Krell KRS2, the Mark Levinson No.26, and the Threshold FET-10. However, the Seven costs considerably more than the most expensive of these, and is, in my opinion, inferior to all of them in terms of user convenience.

All three solid-state preamplifiers fall into the category of being neutral enough that a simple bypass test reveals no differences. Only prolonged listening does. The Premier Seven is not quite that nearly perfect, due to its thinned-out low end.

Just three years ago (before the introduction of the Audio Research SP11, in fact), even the "best" tube preamps were obviously inaccurate—much, much more so than the Premier Seven. But their imperfections were of a kind which tended to glorify the sound of music—to make it richer, rounder, fatter, sweeter, warmer, and more spacious than the signals fed into them. Tubeophobes used to call that cornucopia of colorations "euphonic distortion," but tubeophiles would pay a premium for it, even while acknowledging that it was probably less accurate than the pristine coldness of some top transistor amplifiers. Designing a tube preamplifier as uncolored as the Premier Seven is a tour de force, but in doing so, Conrad-Johnson has effectively eliminated the Premier Seven from consideration by those who crave that tube sound.

Tube equipment, however, must cost more than solid-state, if only because capacitors and power transformers have to be much bigger in order to handle the much-higher operating voltages required by tubes. And as long as tubes had "the tube sound" and solid-state had "the transistor sound," consumers who heard the difference were happy to pay the premium. But as transistors become less transistory and tubes less tubey, it's increasingly difficult to justify the ever-widening price differential.

For example: Except for its low end, the Premier Seven is sonically comparable with a stock Threshold FET-10, which is one hell of a good preamp that costs $3550, rather than the Seven's $7850. (After borrowing my stock FET-10, Dick Olsher refused from then on to use anything else. He now has his own.) But now compare the Premier Seven with my reference preamp combination, the FET-10L line stage beefed up with the John Curl power supply, coupled with the Vendetta Research SCP-2 phono preamp, and there's not much contest. While the Seven does almost everything right, the customized FET-10 combo is a shade better in almost every respect. It has slightly better inner definition, a very slightly more open-sounding high end, and a low end that is definitely better. Only in image depth—front-to-back perspective—does the Premier Seven outshine it, but only by a small margin. The truth is, the beefed-up FET-10 is hard to fault (footnote 3). On top of that, the FET-10 has a mono mode, a foolproof tape-loop circuit (two, in fact), a stereo reverse switch, and two more line-level inputs than the Premier Seven. The total cost of the beefed-up Threshold? $4595.

There is no question but that the Premier Seven is a superb preamplifier, ranking sonically among the best. The question is, is it worth almost twice as much as its sonic competition? I don't believe it is.—J. Gordon Holt

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Footnote 3: I say "hard to" merely as a sop to those who would jump down my throat wearing chain mail if I dared admit that, after six months, I still cannot hear anything the matter with the Threshold/Curl combination. But I must come clean: I can't.