| Since my first listen to a Threshold SL-10 and my later hours with a pair
of SA-12es driving Maggie 3As, I have found that music tends to come along with the
designs of Nelson Pass. My nostalgia for the Threshold of old is not shared by Pass. I
suppose this speaks volumes about my abject sentimentality and his drive to make ever
better and better amplifiers. To be honest, I had reservations about his foray into the
realm of the single ended transistor amplifier. On one hand I knew that they had to be
more neutral and therefore more true to the music than the hapless, tube SE designs that
had begun to litter our Hi-Fi highway. Still, I did wonder for awhile whether Pass had
succumbed to the siren song of trend and fad. I later learned that I had no reason to
worry. The Aleph 0s is quite large and heavy for a 40 watt stereo amplifier. Its heft
and size are a function of the Aleph's asymmetric Class A operation, which according to
Pass "makes ordinary push-pull circuits appear comparatively efficient." Knowing
well of the rapid enthusiasm of the TAO readership, I will spare you all another
description of the Aleph 0s looks. I'm sure you've all seen one, or at least looked at a
photograph. For myself, the Aleph is quite nearly the epitome of the form follows function
doctrine; the amp needs lots of heat sinking, so give it lots of heat sinking and let the
look of the amp be dealt with by the interior designers of the world.
As I think back, the most identifiable qualities of Nelson Pass-designed amplifiers
have been their ease under fire (ability to remain calm when mated to a speaker that
presents a tough load) and the crystalline clarity of their mids and high frequencies. The
Aleph 0s maintains these attributes while adding a sense (a sound?) of coherence that is
quite difficult to describe, though I shall try.
When I listen to "The Pain of Loving You" from Trio by Dolly Parton, Emmylou
Harris and Linda Ronstadt (Warner Bros. 9 25491-2 [cd]) through the Aleph 0s, I can hear
each of the three voices and their individual characteristics. Each voice stands distinct
in both its physical placement and presentation. What the Aleph 0s brings that is not
heard in lesser designs is the seamless joining of the voices into a musical whole.
Somehow, the Aleph 0s so completely delineates between the separate voices that they
are drawn together into a trio (excuse the pun) rather than merely three discrete voices
thrust at the listener.
This review has brought me closer to a notion that has been gnawing at me for some
time, that there is a relationship between tonality and image precision that has not been
widely discussed. What can be heard so easily from the Aleph, in mono, is its utter
clarity of tone. What can be heard in stereo is its ability to take this clarity and
define spatial issues with ease. This quality is well heard in a recording by a trio of
another color, so to speak, the Amsterdam Guitar Trio's version of Debussy's
"Passipied" (RCA Victor 78002-RC [cd]). Here we find the same degree of tonal
truth, each guitar sounding unique, and the same sort of retrieval of acoustic space and
performer localization. Again, the sound is unfettered and free of elect or character. In
fact, these terms seem out of place in a description of the performance of this amplifier.
Yeah, but does it rock? In fact, it does. In common with most of his designs, the Aleph
Us continues the Nelson Pass tradition for stoutness under load. While the Aleph Us does
40 watts into 8 ohms, it doubles into 4 ohms and continues to increase its power output as
the load impedance decreases. This current capacity makes the amp far more suited for a
broad variety of loudspeakers than one may initially suspect. More significant for the
music lover is the fact that the Pass is unfazed by highly complex musical waveforms. In
the finale to Mahler's massive Symphony No.4 (Sony SK 48380 [cd]), things get hot and
heavy with soprano Barbara Hendricks and full orchestra going at it. The movement is
highly dynamic, shifting from loud to louder, and from softer to the brink of silence.
With strings and brass, dueling with voice and percussion this represents as staunch a
test for amplifier resolution as I can find. The Aleph Us is superb on such works, fairly
relishing in the quantity and quality of musical detail and margenalia, and all the while
conveying the music whole in an almost tactile manner.
Yet, is this enough power? Who knows? I found that it drove virtually every speaker
that crossed its path to full levels, and without strain. Still, sometimes there's no
substitute for cubes, to borrow an automotive cliche. In the end, just be reasonable. If
you have a 30' by 50' foot room, do not use the the Aleph 0s to drive all four columns of
your Genesis Ones. Consider the specs (a watt is a watt), look at the size of your room
and the sensitivity of your speakers, and most importantly, honestly appraise your taste
for the bombastic and your need for power for the sake of power. Power related hedging
aside, the Pass Aleph 0s is one marvelous amplifier. Highly recommended. |
