Tube Preamp Reviews

Everyone knows that world-class analog and digital sources are the bedrock of all fine audiophile systems. Everyone also knows that a happy relationship of amplifier, speakers, and room makes audiophiles smirk Aren't I lucky? Fewer among us are aware that the upper limit of sound quality an audio system can deliver will be established by whichever audio contraption we use to select our sources and adjust their volume.

"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.

It's a reviewer's privilege to be able to switch back and forth between tube and solid-state gear (or combinations thereof) as the mood or the assignment moves him. Still, I find I'm inevitably drawn back to the Epicurean delights of triode tube gear. When done right, there's an alluring musicality to it, like the breath of life. However, in any tube vs solid-state contest, the relative tradeoffs between tone and resolution—sweetness and articulation, euphony and frequency extension—must be taken into consideration.

Every day in my bunker, I use one of a few high-quality headphone amplifiers to double as a line-level preamplifier-controller and operate as the quality-assurance reference for my ongoing audio experiments. I must choose this component carefully, because it determines the upper limit of my system's ability to reveal any subtle differences among components under review.

Pulitzer Prize–winning poet Mary Oliver famously remarked, "attention without feeling . . . is only a report."

After nearly two years of prattling for Stereophile, I am finally grasping the full veracity of that statement. When I read reviews that jabber on about highs, mediums, and lows, and that rely exclusively on nonmusical vocabulary, I come away with feelings of acute cognitive dissonance. Not to mention: if a review has a lot of initialisms—ADD, S/PDIF, DXD, HDMI, etc.—my ADHD kicks in and I stop reading by the third paragraph.

What am I doing with a vacuum tube preamplifier? I haven't owned a tubed preamp since I bought a Sonic Frontiers Line 3 preamplifier at the turn of the century. I set that aside within a few years as I moved into multichannel because multichannel tube-based electronics were, and still are, rare. My last home experience with a vacuum tube was with a PS Audio Stellar M1200 monoblock power amp, which is a hybrid with a 12AX7-based input stage.

In just a few years, Sonic Frontiers has evolved from a parts and kit vendor to a full-line audio manufacturer (footnote 1). Their initial offerings were well received, but their kit origins were apparent in the layout and cosmetics of their products. While SF still offers kits (like their high-value Assemblage DAC-2), the new line of vacuum-tube electronics has world-class construction, design, and packaging. This generation of SF equipment is evidence of their advanced evolution, even though their constructor genome can be detected in the use of audiophile-preferred, as opposed of OEM, components.