Reviewer: Srajan Ebaen
Source: Jolida JD100 w. Underwood HiFi Level-1 mods; Eastern Electric MiniMax CDP; Cairn Fog v2.0 24/192
Preamp/Integrated: Eastern Electric MiniMax preamp; Antique SoundLab MGHead DT/OTL 32 [on review]; Unison Research Unico
Headphones: audio-technica ATH-W1000; Sennheiser HD-650 with Stefan AudioArt wire harness; AKG K-1000 with Stefan AudioArt wire harnesses
Amplifier: Bel Canto Design eVo4 Gen.2
Loudspeakers: Anthony Gallo Acoustics Reference 3
Cables: all Crystal Cable Reference
Stands: Grand Prix Audio Monaco with one GPA Formula Carbon/Kevlar shelf and Apex footers/levelers
Powerline conditioning: BPT BP-3.5 Signature; Walker Audio Velocitor; 2 x ZCable Cyclone Ref1 power cords
Review component retail: $595 including tube cage
Cheap'n'cheerful! That's how some folks think of the Chinese Antique Soundlab marquee which is represented for our American provinces by the affable Tash Goka of Divergent Technologies in Canada. Cheap and cheerful? That didn't prevent Harry Pearson to fall in love with the ASL Hurricanes. He waxed so eloquently about them in the hallowed pages of The Absolute Sound as to create major ripples in our brackish audiophile backwaters. Then words got out that Joseph Lau of ASL/TubeHiFi employs many of the same circuits as certain hyper-expensive WAVAC amplifiers from Japan pride themselves on. None of that has really helped the - er, cheap and cheerful reputation of Antique Soundlab.
Needless to say, on raw chassis, controls and parts quality alone, Antique Soundlab will never compete with the glitz crowd on its own terms. But then, was that ever part of this firm's mission statement? No. The question really comes down to how good their stuff sounds for the very competitive pricing asked and whether reliability is an issue. Naturally, we'll discuss how the first part of that question pertains to today's 5AR4-rectified 4 x 6BQ5/EL84 headphone amp/ preamplifier. All I can say about reliability? The importer/distributor is a very upstanding individual whom I've met for years at the various tradeshows of our industry. I would be surprised if his customer support reputation with actual owners of his products were anything other than stellar.

The 'Head' (or 32 as I shall refer to today's piece for brevity's sake) is a 19 lbs. black affair of 13"x 9.5" x 9" WxDxH dimensions with a removable tube cage and a total of seven small valves: The 5AR4/GZ34 rectifier in the left third of the top's rear not occupied by transformer casings; the four EL84s arrayed in a semi arc in the middle of said top; and the two 12AU7s right in front of the two outermost output tubes. Four line-level RCA inputs, two pre outs and an IEC power inlet with separate fuse bay make up the rear panel. A power mains rocker, volume control and input selector are among the expected front panel items. What's between the two rotary fascia controls is how the little Head distinguishes itself: A standard 1/4" headphone socket with lock mechanism; a locking 4-pin XLR input for the AKG K-1000 headphones; and a toggle switch to select headphone or preamp operation. A second toggle on the top edge selects between hi and low gain.

The OTL in the nomenclature refers to output-transformerless operation while the DT stands for Divergent Technologies (not dual transformer) to indicate a design that has benefitted from certain features and modifications commissioned by the distributor. In a few weeks, the unit which I received for review will have been replaced by a newer version that incorporates a hardwood remote and chromed tube cover with no other changes to the appearance. The circuitry remains altogether untouched. The price for the remote DT/OTL 32 will be $675 and replace the current non-remote version. Does this sound to you as though Tash Goka listened to customer feedback?

The brutish 74dB/1w/1m behavior of AKG's famed and notorious top earspeakers explains why their stock wiring harness terminates in speaker-level ends - you need a regular amplifier to drive them with. The previously reviewed Chazz also sported the Head's 4-pin direct-input XLR but my review indicated less than stellar results with it. The designer subsequently agreed with my findings when he took delivery of a pair of AKGs himself. I've long since been on the hunt for an affordable amp for these unusual cans. My Unison Research Unico works splendid indeed but is more expensive than I was hoping for to make a cheap and cheerful system recommendation. The ASL MGHead Si 15 requested earlier for that perfect tango session went into oscillation when faced with the K-1000s. As a speaker-drive amp designed for 4-8 ohm loads, it clearly wasn't optimized for the AKG's 120-ohm impedance despite its attractive 15wpc power rating. Mr. Goka managed to duplicate my distortion results on two of three Si 15 inventory amps he had on hand and agreed that this particular headphone/amp combination, after all, was not the good idea it promised to be on paper.

Imagine my surprise then when Tash contacted me once again for another heady go-around with my winged earspeakers. Two puny direct-coupled 6BQ5s per channel were now supposed to do the dirty deed. "No way José" was my instant objection. "Hear me out" countered Tash patiently. As he explained, designer Joseph Lau had discovered that it wasn't raw power the AKGs were after, it was high voltage they wanted. Tweaking his circuit in conjunction with an actual pair for testing, the $600 Head, lo and behold, indeed does drive these cans louder than you'd want. I stand corrected. Before I make proper amends for my contrarious assumptions with aural descriptions, first a few specs. With 32-ohm loads, the headphone output offers a claimed frequency response of 13Hz - 19kHz, a S/N of -64dB and 10mW of power. Into 120-ohm loads like the AKGs, output power increases to 18mW while S/N improves to -77dB. Into 300-ohm loads, output power becomes a whopping 1/3 of a watt while signal-to-noise goes up to -80dB. Meanwhile the Head consumes 58 watts from the wall. Operated as a 13dB-gain preamp, input sensitivity is 580mV, frequency response 11Hz - 36kHz, noise remains -80dB and output voltage becomes 2V max.


Popular lore has it that to tame the shrew that is the K-1000s requires about 10 watts of manly amplifier power. AKG's own website specifies that between 400mW and 1 watt will equate to about 100dB of -- absolutely ear-wilting -- sound pressure levels (they mention either figure in this context). That makes the Head's 18mW look positively and terminally malnourished. Yet this minuscule fraction of a measly watt works as advertised. This is nearly as disconcerting or unbelievable as discovering that I could drive my 88dB Gallos with 8 watts of nearfield Eastern Electric power. While on that subject, a brief comment about today's system listing. I deliberately attempted to evaluate the Head's preamp performance in as sane a context as my current hardware assortment allowed for. I downscaled associated and usual expenditure on the source and speaker front but didn't have a likewise affordable solid-state amp in-house. I could have used the MiniMax but wanted the superior noise floor of a transistor amp to optimize the Head's performance which, if you've paid attention, doesn't sport terribly impressive S/N figures. That's par for the course with affordable tube products but meant that in order to emphasize rather than obscure the Head's sonic contributions, I should use as lo-noise an amplifier as possible. Hence the Bel Canto eVo4 Gen.2. I would, however, borrow MiniMax' luxo Mullard GZ34 rectifier valve to indulge in some minimal tube rolling just for kicks.