Solid State Preamp Reviews

Compared to the Krell KSA-300S power amplifier that I also review this month, the KRC preamp's design is, at first glance, almost conventional. But its thoroughly high-end internal design has been equally well thought-out and executed. Its main, four-layer, glass-epoxy circuit board is for the audio signal, DC power, and ground—two layers for the latter are said to minimize noise. The gain stages are pure class-A and complementary. As in the amplifier, the circuit is direct-coupled, with servo circuits controlling the DC offset. The fully regulated power supply is housed in an external chassis. Seven inputs are provided: four single-ended, two balanced, and one single-ended tape. All inputs are line-level except for the optional, single-ended phono stage. (This review will address the line stages; a Follow-Up will discuss the phono stage's operation.) There are three outputs: balanced and single-ended main outputs, and a single-ended tape output.

There's always a certain amount of jockeying for position at the very top of the High End. Every few months, a new star burns brightly, getting all the attention. While the constant turnover at the cutting edge helps to define the state of the art, audiophiles should keep their eyes on the longer term. It's a company's track record—examined over a period of years—which defines its position in the market and the credibility of its products.

About a decade ago, I read in Stereophile about the SRC, an add-on remote-control unit manufactured by Acoustic Research. I bought one the next day ('swhat happens when you work across the street from a hi-fi shop). Suddenly I was able to make incremental changes in volume and balance from my listening position—and let me tell you that that's the way to do it. What a phenomenal difference in realistic dynamics and soundstaging.

The KSL ($1800, $2100 with phono section) is a one-box line controller/preamplifier, just 2.25" high, with a nominal voltage gain of 10dB, or 3x. Despite its moderate price, the KSL is distinguished by having balanced outputs (via industry-standard XLR connectors), as well as two balanced inputs. Conventional single-ended, unbalanced outputs are also available via a pair of gold-plated phono sockets. Two unbalanced inputs are provided, plus a third via the tape monitor switch.

"As the original L2 circuitry was virtually flawless, it was the emergence of new electronic components that opened up a possibility of [even better performance] . . ."

So begins one of two booklets—one a collection of specifications and interior photos, the other a distinctly thorough user's manual—included with the new L2.1 Reference line-level preamplifier from Brooklyn's Lamm Industries, earlier products from which have impressed me as among the best available. Indeed, coming from almost anyone else, the above quote would strike me as trivial boasting—but I know from experience that there's nothing trivial about designer and company head Vladimir Lamm.

I've spent six-odd years in a sort of hi-fi counterculture, playing with things like mono cartridges, one-box CD players, and cheap, homemade cables—and, of course, owning and listening to single-ended triode (SET) amplifiers and horn loudspeakers. But before all that, I owned components that, while more mainstream, did the job just as well in certain ways. That category included solid-state electronics (Naim, BEL, Spectral), dynamic loudspeakers of middling efficiency (ProAc, Epos, Magneplanar), electrostatic loudspeakers of very low efficiency (Stax), and even "high-end" accessories like Tiptoes and Shun">http://www.stereophile.com//features/69/">Shun Mook Mpingo discs (which I still have, although my five-year-old daughter has more or less permanently co-opted the latter for playtime use).

This review should have appeared more than a few months ago. When I reviewed Linn's">http://www.stereophile.com/phonocartridges/987linn">Linn's Troika cartridge back in the Fall of 1987, in Vol.10 No.6, Audiophile Systems also supplied me with a sample of the Linn LK1 preamplifier and the LK2 power amplifier, which I had intended to review in the due course of things. As it transpired, however, I was less than impressed with the LK2, finding, as did Alvin Gold back in Vol.9 No.2, that while it had a somewhat laid-back balance, it also suffered a pervasive "gray" coloration, which dried out recorded ambience and obscured fine detail.