Reviewer: Srajan Ebaen
Source: Resolution Audio Opus 21 [on review]
Preamp/Integrated: Antique SoundLab MGHead DT/OTL 32 [on review]
Headphones: audio-technica ATH-W1000; Sennheiser HD-650 with Stefan AudioArt wire harness
Cables: Crystal Cable Reference interconnect and power cords
Stands: Gingko Audio Cloud 11 platforms
Powerline conditioning: Walker Audio Velocitor
Review component retail: $1,995 direct/dealer

Every reviewer needs secret weapons and agents to get ahead in this age of gnarly information overload. Getting data is easy. Processing for meaning and what to take serious is the challenge. With a double curtsy to Superman's Kryptonite and Alan Kafton's last name, one of my magic potions is called Kaftonite. Alan of course is the maker of the World Power conditioner and audiodharma CableCooker. He's a true enthusiast who has his finger on the pulse of various audio forums and the audiophile grapevine in general. He also knows I have peculiar tastes. Occasionally, kryptonic notes appear in my InBox to hip me to kaftonik new products. Kewl. Hey, I need all the help I can get to stay on top of that department. Today's unexpected discovery was one of 'em. I'd never heard of Classified Audio Video Inc. of Jacksonville/IL before. Ditto for their brand Aural Audio or their no-holds-barred Class A headphone amplifier called the Aural Audition. Pretty suggestive name if you ask me - Aural Audition. How to resist?

After clicking on Alan's URL hotlink, it took exactly four minutes and 39 seconds to fire off an introductory e-mail to owner Larry Black and inquire about review interest. Not long thereafter, Mr. Black replied in the affirmative and promptly dispatched a review loaner. An up-and-coming audio manufacturer who actually communicated and responded? My world was falling apart. Were the Nephilim from the 12th planet landing prematurely in my yard? I wasn't ready yet to build off-planet pyramids again. I confess all of this sent me into today's assignment favorably pre-impressed.

And no, I won't go into details about the communication business save to say that Stereophile's John Marks has it absolutely right - some manufacturers in this industry would do well to learn from Larry Black before Joe Black books a visit instead. The Aural Audition turned out to be one chunky-deluxe customer, using 1/2" machined aluminum all around whose various panels were locked together with unusual tri-socket security bolts which to crack would require a specialty key not likely stocked by my local ACE hardware store. Off went another e-mail to Larry who promptly sent the above image of the innards for public consumption while I took a quick tour of the externals only.

Vault-like construction, engraved nomenclature and an utter lack of frills clearly telegraphed single-minded purpose and no-nonsense seriousness. One set of Switchman inputs, one IEC, one fuse holder on back, a blue power LED, a 23-step DACT CT-2 resistor-ladder attenuator and a single 1/4" input on the front were it. No preamp functionality; no second headphone jack; no second input. I could hear the beast speaking to me. "How many sources are you gonna listen to at once? If you make me into a preamp, how often will you actually listen to my headphone socket?" Hard to argue with any of that if -- to borrow a pet phrase of Dennis Had -- you're into deep can (he prefers triode but you get the drift). Of course then there are the Mexicans and the Mexican'ts but that's better watched on video (El Mariachi Part III).

As per Aural's literature and Larry's additional comments, the Audition was built by fet men - it's an all-FET design with a low-noise power toroid. Vishay-Dale and Caddock resistors, Nichicon Fine Gold Muse electrolytics and Mica or Polystyrene compensation capacitors are found throughout the amp which is said to be happy driving headphones from 32 to 600 ohms. A JFET input servo amp tracks output offset to less than 1mV and operates below 1Hz to be sonically inaudible.
The power supply consists of fast recovery diodes, eight low ESR filter capacitors and dual wide-band, low-noise regulators, again using only FETs (JFETs and MOSFETs) as active elements. The Audition employs separate and independent 200mA peak-current power supplies with separate windings within the transformer; PCBs with 70-micron silver traces; all silver signal-path wiring and 2% silver solder. Gain is given as 20dB, output impedance as <2 ohms, rise time as < 0.2us and power consumption as 18 watts. Dimensions are 8" x 4"x 12.75" WxHxD. Weight is 17 lbs and parts & labor warranty 3 years. The designer of the Audition amplifier is Erno Borbely, formerly lead systems engineer for Hafler, Dynaco and Motorola Semiconductor.

Though the website doesn't reflect it yet, a press release from late last year mentions the Aleron and Camber 70 and 40 watt pure Class A mono amps; the Telo 70wpc pure Class A stereo amp; the Cortege preamp; the Portal DAC and the Wayfarer monitor and Capstone fullrange speakers. Someone at Aural is thinking big and smart. CES 2004 solicited industry feedback on this planned rollout to insure that it was found sonically competitive with what the market currently offers. As Larry put it, "We were amazed with the results". For today, let's focus on the Audition pure Class A headphone amplifier that runs only modestly warm and gives off absolutely zero transformer hum. Over my HD-650s, it was dead quiet with the attenuator fully bypassed (wide open). With my 40-ohm 100dB W1000s, it exhibited first onset of very mild power supply 'rush' at the 12 o'clock position. For reference, 4-5 clicks up from mute meant average playback levels for the W1000s, i.e. well below this threshold. The Sennheisers needed an additional 2+ clicks for equivalent playback levels, leaving an absolutely ridiculous amount of headroom for either can, something that's possibly needed by less efficient 'phones or 'tougher' loads and likely one reason why the amp runs so cool.