A few sonic items struck me immediately and within the first five minutes of aural auditioning. One, the amp is ultra quiet. Because of that, it's very dynamic. Once you set the median volume to where you usually set it on other amps, you might be surprised when the first peaks and climaxes you didn't categorize as such race down your ear canal and come knocking on your fragile door with the force of a medieval battering ram: "Whoa Nelly - d'ya see that wicked gust blow up me kilt? I ain't wearing no bloody briefs!"


The next thing you'd notice is relaxed resolution which clearly allowed me to hone in on the respective voicing of my HD-650s and especially the W1000s. More on that in a moment. For now, let's make sure to describe this resolution properly because it is not hyped or etched by any stretch of the imagination.


It's simply the result of an extremely low noise floor coupled to a very neutral sound with just a slight trace of warmth. While the Audition doesn't sound like the valved Antique SoundLab at all -- the latter is denser and thicker while clearly less resolved and thus a bit dirty by comparison -- it doesn't exhibit the relative coldness or dryness of typical solid-state either.


I remember Wes Phillips' descriptions of the HeadRoom BlockHead amplifier powering his HD-650s in true dual-mono drive. While perfect for recording mastering sessions, he called it the equivalent of sensory overload - too much detail to be fun for relaxed pleasure listening. I haven't heard Tyll Hertsen's assault on the bleeding edge in that setup to have any personal comments. However, the Aural Audition's way with shining the spotlight into the deepest recesses of the soundstage distinctly did not elicit the kind of recoil reaction Wes described. Its designer remained clearly cognizant of this potential issue that always raises its scaly head when ultimate detail recovery becomes an overriding concern. How to fold these details back into the overall gestalt of the music? It nearly mandates to take a few steps backwards to re-integrate those details into the now bigger picture.


In the Polish Bros.' brilliantly eccentric but elegiac movie Northfork, Anthony Edwards plays a Gypsy-like art appraiser who might be a fallen angel. He wears a kaleidoscope of magnifying glasses and approaches his art objects so closely as to practically touch them with his lenses. The Audition is much easier on the eyes/ ears than that. It's very cannily balanced to give you new insights into your recordings without making any apparent efforts or forcing you to make them instead. While clearly a magnifying device that should appeal to recording engineers as a monitoring tool, it's simultaneously also a music-making device. And while that sounds like how it should be, it often doesn't work out that way.
I mentioned how easily this amplifier allowed me to appreciate the respective voicings of the headphones plugged into it. Alternating between the vise grip of the Sennheisers and the greater wear comfort of the Japanese cans became a quick and completely unambiguous display of specific signatures. The relative ease of distinguishing between them became a suggestive indicator for how transparent the amp itself was to facilitate this aural inquiry. In my review of the Eastern Electric MiniMax CDP, I mentioned how the audio-technicas took the lead over the HD-650 when plugged into not a dedicated amplifier but a tube-driven headphone socket of a good affordable 6922-based CD player. The Audition levelled the playing field by now providing the Sennheiser's impedance with the proper drive to show off their true colors.

The 650s are the more neutral of the two, with the W1000s using some deliberate presence lift and warmth to, subtly, mimic a bit of tube-based vocal lock that brings voices slightly forward - if directional cues like 'forward' make much sense to you when confined to the interior of your skull. What really is forward then? It's truly more of a centralized focus deep inside the grey matter but I'm sure you can translate this term appropriately. I personally fancy this effect very much but it's also fair to point out that it's probably not 100% honest. However, where the W1000 seem to outscore the Sennheisers regardless of listener bias is in dynamic envelope. Could it be their sealed design? Whatever the technical contributor, the audio-technicas have a bigger and bolder sound which combines slight warmth, more developed bass, a presence region contour and expanded dynamics.
The HD-650s strike me as the more linear, technically more 'truthful' headphones of these two and thus preferable for monitoring purposes where even minor editorializing becomes bad juju. However (or should that be more properly just 'and'?) - I do prefer the wooden cans for pleasure listening. More important than my personal preference in today's context is naturally the Aural Audition's distinct ability to heighten rather than homogenize such differences between headphone models from different firms. The more neutral a device, the more it should reveal distinctions between associated components. This silver hunk of an amplifier obliged most willingly also with various digital front ends whose delta of performance in their exalted leagues (Accustic Arts, Ensemble, Zanden) is a tiny cracked fissure in dry soil, not any dramatic canyon like the kind the Rio Grande has carved out of the bedrock here in Northern New Mexico.


Suspended as it was in aural pleasures and thus unlikely to be very analytical, I racked my brain to hit upon just the right pointer to help you imagine our review subject's 'sound'. I came up with Pass Labs as the most likely candidate. If you've heard their amplifiers -- think halfway between the X and Aleph Series -- you'll have a very close aural imprint in your grey matter of the Aural Audition: Ultra dynamic; close to neutral but not cold; distinctly lacking in transitory bite, glare, etch or pancake flatness; not dark like older Rowland designs. While you shouldn't, you can crank this amplifier up to deafening levels to notice -- at least over the very brief period I endured -- that it suffers no shifts in tonality or any of the telltale signs of compression. Things just get louder and scale in linear fashion.
Back to resolution. My freestanding Avantgarde Duo loudspeaker rig is not one to be considered lacking in that department at all. However, removing the room and the intermediate buffer of air separating the listener from the actual transducers which do require that distance to align as an apparently unified sound source; and listening to advanced electronics like this American-made headphone amplifier did let me hear things I usually don't notice to that extent. It's no secret that I enjoy Flamenco as a genre and particularly its vocal traditions for the powerful emoting that includes top-of-the-lungs shouting while the voice breaks up; peculiar warbling; metallic overtone modulations that often produce subtle harmonizing as though the vocal cords doubled or tripled up; and rather unconstrained dynamics. One of the most versatile masters is Diego Clavel who resurrects various dying styles of vocal deliveries and encompasses a terrific range from the most restrained whisper to rip-roaring fury.
La Malagueña a través de los tiempos [Cambaya 012.F2]

If you've ever played the children's game of enunciating out loud all the vowels in sequence and on the breath (a-e-i-o-u) and even inserted intermediate values like 'ä', 'ö' and 'ü', then exaggerated each of them to the hilt, you know how each activates different vibrations that travel up into the skull or back into the throat or down into the belly. Inserting a rolling 'r' adds certain harmonics. Feeling this in your own body is different and more tangible than hearing someone else do it. And that's what I was getting at with this example. The Audition allowed me to crawl inside Diego's voice as though experiencing these modulations in my own body and specific locations therein. Additionally, I could unequivocally feel what was generated by the vocal cords and what was mixed into the voice by reflections from the room he sang in.
These are the kind of 'internal' explorations headphone listening encourages. You aren't distracted by soundstage phenomena or the more visceral skin impact effects of fullrange systems moving serious air in a room. The greater intimacy and immediacy of headphone listening instead puts you inside the music in a different way. It's not better but simply different. The Aural Audition amplifier is a champ at simulating a powerful sense of feeling hardwired especially to vocalists of well-recorded albums. This information will be present as well in a superior loudspeaker system but then becomes somewhat diluted. Here it is completely obvious yet not at all distracting from the musical message.


Audiophiles not hip to superior headphone rigs would be completely flabbergasted by what their premium rigs still leave on the table in this regard. The Aural Audition is clearly a very serious take-no-prisoners attempt at a state-of-the-art headphone-driving device. Is it the best of its kind? I wouldn't know. I do know that it's the best I've heard yet - for whatever that's worth. It's expensive and thus quite exclusive. After all, most headphone aficionados are DIYers who love to experiment lack the big bucks. That's precisely why they're into cans to begin with - you can get superior sound for far less than going the speaker route. Exactly who will be deep-can enough to give the Audition a try outside mastering engineers who do this for a living? I'm not sure


I am sure glad of having had the opportunity to experience what still separates my current setup from something as uncompromised as this dedicated amplifier design. Especially over my W1000s, it gave me both audiophile and musical thrills aplenty. When that happens, you find yourself temporarily in a zone outside our pathological urge to endlessly upgrade or in many cases just change what we have become used to and bored with. Classified Audio Video's Aural Audition Class A headphone amplifier, from what I can tell, is for the chosen few who want the very best. At $6,000, there's of course also the Holmes-Powell DCT-2. Its price suggest either a sterling performance or a rip-off or both. There are headphone units from luminaries like Tim de Paravicini and Berning which possess all the ear markings of due consideration in these leagues. Not having heard them, I can only suggest that if you're shopping in these Rodeo Drive neighborhoods, to also stop at today's address in Illinois.

Musical satisfaction can be had for a lot less bread of course. The $600 ASL MGHead DT/OTL 32 currently in for review proves that without a doubt. Alas, a double date with musical and audiophile satisfaction -- or emotional conviction and ultimate appreciation for the finer dimensions of raw data retrieval -- is usually an impossible function of Biblical proportions. Something about a camel and the eye of a needle. I've never understood what one has got to do with the other. I mean, do camels sew? Not. But the Audio Audition would have you believe that they might. And that's a rather mean trick. The Audition avoids the peculiar overall dryness, chalkiness and too incisive handling of transients that can plague other going-for-rez sand efforts. It also doesn't inject gratuitous warmth or curtails treble extension to err in the opposite direction. Neither does it sound like an affordable tube unit. In other words, everything's on higher ground and in balance. And while the Buddhist Middle Path seems too serene for extremists at first, it usually is the healthiest and most beneficial long-term choice to make. If he'd been into mature pleasures rather than formal asceticism, Old Shakyamuni would have really liked this Audition amplifier. His ears were certainly big enough...
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