Tube Preamp Reviews

In appearance Conrad-Johnson's PV4 is distinctly plain: a basic black and silver box with a few simple knobs and buttons. The controls are logically laid out, clearly labeled, and work properly. The two channels track well through the volume control, maintaining balance; pushbuttons and control knobs have a smooth, solid feel (except for the noises audible through the system when switching inputs). Don't forget the turn-on and turn-off thumps mentioned above; the PV4 is the only one of the preamps I review in this issue—the others are the Audible Illusions Modulus ($450) and the Counterpoint SA-7 ($595)—that lacks a mute switch.

In the March 2018 issue, Art Dudley admired the sound quality of Ayre Acoustics' KX-5 Twenty preamplifier, but didn't love some of its operational aspects. I've staged this Follow-Up as a putative face-off between the Ayre and my current reference preamplifier, the PS Audio BHK Signature, which I reviewed in the June 2017 issue.

In appearance the Counterpoint SA-7 tube preamplifier is quite attractive, possessing the thin, low-profile look currently in vogue. There is a mute switch which (if you remember to use it) protects your amplifier from the preamp's turn-on and turn-off thumps. Unfortunately, the volume control on my unit didn't track accurately, and it was necessary to adjust balance with each change in volume. One unusual feature: the balance control allows very fine gradations in balance adjustment (a large movement of the control results in a small change in balance).

In January of 2014, some of us wondered if the sudden death of designer Ken Shindo would spell the end of the company he founded in 1977: It was hard to imagine Shindo Laboratory being led by anyone but its founder, a former Matsushita engineer who made it his life's work to study not only the designs of audio's golden age, but to learn the sound of every vacuum tube, every passive part, every circuit variation that he might reasonably press into service.

Better known for their speaker cables and interconnects, The Absolute Reference Audio Labs (TARA Labs) has quietly branched out into electronics and loudspeakers. Their Passage is a line-level–only preamp. I actually favor such a modular approach to preamp design. Standing as we are at the dawn of the digital audio age, the breakup of the traditional preamp into separate phono and line-level stages represents a more flexible, cost-effective design approach.

"Let be."

Those two words, from Shakespeare's Hamlet, express an entire philosophy of life in one of the shortest sentences possible. The quotation may not be familiar, but the concept certainly is—contemporary equivalents, each with its own inflections of meaning, include: Shit happens. Let the game come to you. Keep calm and carry on. (I hate that one.) Paul McCartney wrote something similar, and only slightly less concise, in a late Beatles song.

The last time I reviewed an Audio Research component—it was the VTM200 monoblock amplifier in January 2001—my hair was mostly dark brown. The wait since has been not of my choosing, but that's now flux under the circuit board. Since then, much has happened to both me and to the Audio Research Corporation, a long-lived company for which the descriptor "legendary" is well deserved.