Description: Single-ended pentode monoblock power amplifier. Power output (at 1kHz): 30Wpc into 8 ohms (14.8dBW). Frequency response: 14Hz-90kHz, -3dB. S/N Ratio: >95dB unweighted ref. full output. Input impedance: 83k ohms. Output impedance: 3.5 ohms. Absolute polarity: inverting. Maximum power consumption: 110W.
Dimensions: 13.5" H by 9" W by 14.5" D. Weight: 42 lbs.
Finishes: Chromed brass, lacquered or unlacquered wood.
Serial numbers of samples reviewed: 22106 A/B (auditioning), 24105 A/B (measuring).
Price: $9970/pair. Approximate number of…
search
Sidebar 1: Specifications
Sidebar 2: Associated Equipment
Analog source: Linn LP12 turntable (fully updated), Linn Ittok tonearm, AudioQuest AQ-7000nsx cartridge.
Digital source: PS Audio Lambda II CD transport, Perpetual Technologies P-1A, ModWright P-3A digital processors.
Preamplifier: Convergent Audio Technology SL-1 Ultimate.
Loudspeakers: Avantgarde Acoustic Uno 3.0.
Cables: I2S: Mystic Reference. Digital: Illuminati Orchid AES/EBU. Interconnect: Nordost Valhalla, Nirvana S-L. Speaker: Nordost Valhalla, PS Audio Lab Cable, Shunyata Research Taipan. AC: TARA Labs Decade.
Accessories: Duende…
Sidebar 3: Measurements
The Audiopax Model Eighty Eight's two Timbre controls make possible a large number of combinations. I decided, therefore, to simplify matters by looking at the drop-dead-gorgeous amplifier's measured performance with both controls set to their fully clockwise positions, which I assumed was maximum bias current, and set as Bob Deutsch preferred: the left control to "11," the right to "3."
The input impedance at 1kHz was a usefully high 229k ohms, and the amplifier inverted absolute polarity. The voltage gain into 8 ohms varied somewhat according to the…
Sidebar 4: Manufacturer's Comment
Editor: Finally! Six long years after Eduardo de Lima's first published papers in 1997, John Atkinson and Robert Deutsch have wonderfully proved the point that Eduardo's been making.
Let's face it, there's no real art or science involved in building an amp that'll drive a test-bench resistive load. It's easy to build an amp with "low distortion." The Crown DC-300 broke that ground over 30 years ago. But the test bench doesn't know what to do with the second-order distortion of single-ended amplifiers. Certainly, if it existed as audible…
Robert Deutsch wrote again about the Audiopax Eighty Eight in January 2006 (Vol.29 No.1):
The second power amp I had around for comparison with the $2795 PS Audio GCC-100 was the Audiopax Model Eighty Eight SE, a tubed single-ended pentode monoblock ($10,000/pair) that simulates the sound of single-ended triodes but with more power (see my review in the May 2003 Stereophile, Vol.26 No.5). The relationship between the sounds of the Audiopax and the Avantgarde Uno speakers is a particularly synergistic one—in fact, the Audiopax was originally imported by Avantgarde USA because of that…
One of the delights of being published by a multinational conglomerate that grows through acquisition, as Emap Petersen does, is that Stereophile finds itself in interesting company. Like La Nouvelle Revue du Son in France, for example, edited by the legendary Jean Hiraga, who turned me on to the sonic importance of wires and passive components almost 25 years ago. And Mojo, an English music magazine tightly targeted on baby boomers like me, who bought their first stereo systems in the '60s to better appreciate the progressive rock we lived and loved by. (I wonder if turn-of-the-millennium…
Letters in response appeared in the February and March 2000 issues:
Music & anti-music
Editor: I was very pleased to read John Atkinson's comments on hi-fi and anti-hi-fi recordings in December's "As We See It." But many people with better hi-fi systems, or even so-called "audiophiles," are not always able to distinguish between musical and anti-musical recordings.
For example, a friend of mine with a decent system recently recommended Sting's new Brand New Day CD as a rather good recording. Listen to it, however, and after a few minutes you notice that the recording is…
Is JA an old fogey?
Editor: I couldn't agree more with John Atkinson's "As We See It" comments in December on CD "over-compression"! Why should all pop CDs sound like they're being played through a radio? I've been mastering for 27 years, and I think we've hit an all-time low.
Editor: I couldn't agree more with John Atkinson's "As We See It" comments in December on CD "over-compression"! Why should all pop CDs sound like they're being played through a radio? I've been mastering for 27 years, and I think we've hit an all-time low.
I can still remember the "level wars" of the late '60s and early '70s, when every producer wanted his record mastered louder than the other guy. But now...every pop CD is "slammed" 'til the little LEDs don't move, from the downbeat to the fade. When you run the D/A outputs through a +4dBm system, you have to…
The modification of disc players is a hot topic on the various audio newsgroups, where the discussion includes do-it-yourself options and the recommendations of commercial modifiers. These range from tweak guys to such serious engineering firms as EMM Labs and everything in between. Not surprisingly, the objects of these endeavors are usually players made by one of the electronic behemoths: Sony, Philips, Technics, Toshiba, etc. In fact, it was just such a discussion that precipitated John Atkinson's purchase of and recent comments on a stock Toshiba 3950 player, a popular target of…
Stereo by default
Despite requiring a video display to access its menus, the UDP-1 comes from the factory with two-channel stereo as its default mode for all formats. Any first-time user can just plug it in, turn it on, and enjoy two-channel CDs, SACDs, and DVD-As, as I did.
Despite requiring a video display to access its menus, the UDP-1 comes from the factory with two-channel stereo as its default mode for all formats. Any first-time user can just plug it in, turn it on, and enjoy two-channel CDs, SACDs, and DVD-As, as I did.
It was a revelation. Each time I popped in a familiar disc, I hoped to catch the UDP-1 out in some characteristic that would negatively distinguish it from what I've heard in the past. No such luck. The McCormack sounded as clean, balanced, and dynamic as all get-out. Violinist Andrew Manze's disc of Vivaldi…