Solid State Preamp Reviews

In the early 1970s, Stereophile's founder, J. Gordon Holt—a man I used to describe, with all due respect, as having been clothed by the haberdasher to the homeless—said that Audio Research's SP-3 tubed preamplifier was "the closest thing available, in fact, to the ideal straight wire with gain" ie, it would amplify the signal without editorializng in any way. Back then, the SP-3 cost $595. Today it would cost around $3500. But TAD's C600 dual-mono, solid-state, balanced preamplifier costs more than 10 times that: $42,000.

It was the strangest thing. In the fall of 2008 I was comparing Ayre Acoustics' then-new KX-R line preamplifier with no preamplifier at all—I was feeding the power amplifier directly with the output of the Logitech Transporter D/A processor. (Levels were matched for the comparisons, of course, made possible by the fact that the Transporter has a digital-domain volume control.) Being a rational being, I knew that the active circuitry of a preamplifier, as well as the extra socketry and cables, would be less transparent to the audio signal than a single piece of wire. I wanted to determine by how much the Ayre preamp fell short of that standard.

One of the most striking aspects of high-end audio is that you can never take any component for granted. Most of the radical change in audio at present takes place in new front-end and speaker technologies, but other components are changing as well—and with at least as much impact in making recorded music seem believable.

The Threshold FET nine/e ($2595) is the junior sibling of the FET ten/e, a solid-state preamp that has earned a rave review in March 1991 from noted tubeophile Dick Olsher (Vol.14 No.3), itself a development of the FET ten that J. Gordon Holt reviewed in September 1987 (Vol.10 No.6). Would my ears, accustomed as they are to the pitter-patter of electrons traveling through a vacuum, have a similarly positive response to the FET nine/e?

I asked for a sample of the K-5xe so I could do a Follow-Up to Sam's review, but other review commitments kept getting in the way. When I finally spent some time with it (S/N 10J002), I found the sound a little on the robust, forward side, which made system matching problematic. Then, as I was about to spill some ink on the K-5xe, I got an e-mail from Charlie Hansen letting me know that the development of the QB-9 USB DAC had led them to rethink the K-5xe's design, and that Ayre would be sending a sample of what would be called the K-5xe^MP. After a longer delay than I had anticipated, the K-5xe^MP, priced at $3500, arrived for review.

The AV7005 is Marantz's second multichannel preamplifier-processor and, at $1499.99, the least expensive pre-pro I've used or reviewed. The Integra DTC-9.8, which has been resident in my stable since 2007, when it cost $1600, and its successors, have since then steadily risen in price. The Marantz's predecessor, the AV8003 ($2599.99), was highly praised in many quarters. I never got my hands on one because, like a churlish child, I felt it lacked features I considered essential. Other reviewers didn't seem bothered by those limitations, or were unaware of them. The AV7005, however, looks and feels like a winner for music and home theater. I see no evidence of skimping—the AV7005 sports such high-end features as balanced outputs, network controllability and streaming, and, of course, HDMI v1.4a for compatibility with 3D and all audio codecs.

When I started out on my multichannel mission in 2000, it was with an all-digital Meridian system that relied on lossy, compressed sources like the original Dolby Digital and DTS formats, or on synthesized surround based on Dolby Pro-Logic or Meridian's own TriField. With the appearance of first SACD and DVD-Audio and then Blu-ray, discrete lossless multichannel recordings became available, but there was no way to output those signals in digital form for interconnection to other components for playback or further manipulation. Most audiophiles, me included, already had analog preamps and power amps. It was only with the appearance of HDMI and the accompanying HDCP content protection that we could output those digital signals, and over a single cable to boot. Today, there are A/V receivers, some costing less than $500, and more than a handful of audiophile-oriented preamp-processors, that can accept such lossless high-resolution multichannel content as PCM, DSD, Dolby TruHD, and dtsHD Master Audio.