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I primarily used Stereophile's loaner sample of the top-of-the-line Audio Precision SYS2722 system (see the January 2008 "As We See It" and www.ap.com) to examine the Audio Valve Conductor preamplifier's measured performance.

Using the preamplifier's impossible-to-read display and following the instructions in the manual, I set up the first pair of line-level inputs for "XLR" operation and the second for "cinch" (ie, RCA). The maximum gain for full balanced operation (ie, XLR to XLR) was 19.3dB for the left channel, 18.8dB for the right, both figures…

That's what I was determined to find out when I took delivery of this $3900 converter, which, though designed for professional recording studios, has found favor with audiophiles (so far, mostly Japanese) wishing to transfer their LPs, 78s, lacquers, and other analog source material to a high-density digital format.

The PSX-100 is an extremely flexible two-channel, 24-bit/96kHz A/D and D/A converter featuring Apogee's…

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Description: 24-bit, two-channel, high-density A/D–D/A converter with UV22 processing. A/D sampling rate: 44.1–48kHz, 88.2–96kHz. D/A sampling rate: 32–106kHz. Frequency range: 10Hz–20kHz. A/D relative THD+N: –110dB (–0.01dBFS). Dynamic range: 116dB. Channel separation: left/right, 120dB (worst case). Analog inputs/outputs: one pair each on balanced XLR. Digital inputs /outputs: two AES/EBU, S/PDIF, ADAT (optical), TDIF (25-pin D). Power consumption: 25W.
Dimensions: 19" W by 1.75" H by 14.25" D. Weight: 12.5 lbs.
Serial number of unit reviewed: 2078.
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Analog Sources: Simon Yorke, SME Model 10 turntables; Graham 2.0, Immedia RPM, SME IV.Vi tonearms; Lyra Parnassus D.C.t, Lyra Evolve 99, Transfiguration Temper Supreme and Spirit cartridges.
Digital Sources: Audio Alchemy DDS•Pro CD transport, Musical Fidelity X-Ray CD player, Marantz DR17 CD recorder, EAD DSP-9000 Mk.3 D/A processor.
Preamplifiers: Ayre K-1, Audio Research Reference Two & Reference Phono Stage.
Power amplifiers: Musical Fidelity Nu-Vista 300, Dyna Stereo 70.
Loudspeakers: Sonus Faber Amati Homage, Infinity Prelude MTS.…

In the main, the Apogee PSX-100's D/A section was tested using the digital AES/EBU digital output of an Audio Precision System One Dual Domain. I also made use of a two-card PrismSound DScope v2.02 and a Miller Audio Research Jitter Analyzer, which runs on a National Instruments DSP PC card.

Looking first at the Apogee's D/A section, with its output set to –10dBV (which is how MF used the converter), the front-panel multiturn pots can still be adjusted to give a maximum output level of 7.3V. With the pots set to give a standard CD output level of 2V RMS,…

Well, we aren't going to argue…

From a well-known amplifier manufacturer

Editor: Thank you for your letter expressing your dissatisfaction with our SPA-140 amplifier. The "hardness" that you hear in the sound is not due to your associated equipment, but stems from a drastic increase in the amplifier's distortion at low power levels. This, we hasten to add, is really quite a common thing in solid-state amplifiers that were designed in a hurry in order to meet the New York hi-fi show deadline.

There is nothing you can do about the problem, except to buy our next-year'…