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This is the 38th in a series of reviews dedicated to the concept of 32Ohm Audio as embodied by the store of that name in downtown Portland/Oregon and described here - Ed.

This review first appeared in the March 2011 issue of hi-end hifi magazine High Fidelity of Poland. You can also read this review of the ADL/Dynaudio system in its original Polish version. We publish its English translation in a mutual syndication arrangement with publisher Wojciech Pacula. As is customary for our own reviews, the writer's signature at review's end shows an e-mail address should you have questions or wish to send feedback. All images contained in this review are the property of High Fidelity orHifiMan - Ed.

Reviewer: Wojciech Pacuła
CD player: Ancient Audio Lektor Air
Phono preamplifier: RCM Audio Sensor Prelude IC
Cartridges: Air Tight Supreme, Miyajima Laboratory Waza
Preamplifier: Ayon Audio Polaris III with Regenerator power supply version II
Power amplifier: Tenor Audio 175S, Soulution 710
Integrated amplifier/headphone amplifier: Leben CS300 XS Custom version
Loudspeakers: Harpia Acoustics Dobermann
Headphones: Sennheiser HD800, AKG K701, Ultrasone PROLine 2500, Beyerdynamic DT-990 Pro
Interconnects: CD-preamp Acrolink Mexcel 7N-DA6300, preamp-power amp Wireworld Platinum Eclipse
Speaker cable: Tara Labs Omega Onyx
Power cables: Acrolink Mexcel 7N-PC9300
Power conditioning: Gigawatt PF-2
Audio stand: Base
Resonance control: Finite Elemente Ceraball under the CD player, Pro Audio Bono platform under CD player
Review component retails: In Poland 1.850zł for ADL, 440zł for Furutech USB cable, 6.690zł/pr for Dynaudios


This is a different test fur us than most others on highfidelity.pl. Usually we deal in individual components by attempting to showcase their assets and weaker points. In such reviews it is important to extract a component from its context and show it as is, not in combination with flaws from accompanying devices. That’s why I conduct such reviews with expensive ancillaries to be as transparent as I have available. Placing testers in a system as it would be composed by an actual buyer only occurs in a supporting role, not fundamentally. I think this methodology is clear and needs no defense. It allows for repeatability and comparable results even over longer time periods.

But today is different. Although the general rules did not change here we focus on testing a complete system. The basis for this decision was a new machine from Alpha Design Labs, a brand launched by Furutech to sell inexpensive kit made in a Taiwanese factory under OEM contract. Their GT40 is a very unusual piece of equipment and a combination of four different machines in one slim box - a USB DAC, a line preamplifier, a phonostage and a headphone amplifier. Hence the GT40 became the heart of today's review system. Signal may be delivered by USB where I used Furutech’s own GT2 cable; or by RCA via line or phono. Outputs are on RCA and a 6.3mm headphone socket. To the former I connected the active Dynaudio Focus 110A speakers to arrive at an ultra-compact highly versatile system that would seem destined for small offices, bedrooms and most of all high-quality computer systems. While not cheap, taking the results of the audition into account this rig defended itself very sportingly against any budgetary accusations of immodesty.


Sound: For this review I used files prepared for an experiment made during one of our Krakow Sonic Society meetings as well as CDs and LPs. Billie Holliday, Songs For Distingue Lovers, Verve/Classic Records, One-sided, 2 x 180g, 45 rpm LP; Brian Eno, Craft On A Milk Sea, Warp Records, WAV 24/44.1; Cassandra Wilson, Silver Pony, Blue Note, 29752, CD; Chris Connor, Witchcraft, Atlantic/Warner Music Japan, WPCR-25166, CD; Clifford Brown and Max Roach, Study In Brown, EmArcy/Universal Music K.K. (Japan), UCJU-9072, 200g LP; Depeche Mode, Fragile Tension/Hole to Feed, Mute Records, 12BONG42, 2 x 180g, maxi-SP LP; Depeche Mode, Ultra, Mute, DMCDX9, Collectors Edition, CD+DVD; Dominic Miller, November, Q-rious Music, QRM 114-2, 2 x 180g LP; Frank Sinatra, Sinatra & Sextet: Live in Paris, Reprise/Mobile Fidelity, MFSL 1-312, No. 238, 2 x 180g LP; Frank Sinatra, The Voice, Columbia/Speakers Corner, CL 743, Quiex SV-P, 180 gLP; Freddie Hubbard, Open Sesame, Blue Note/Audio Wave, AWMXR-0012, XRCD24; Harry Belafonte, Belafonte at Carnegie Hall, RCA/Sony Music, 7783322, LPCD-M2 Mastering, No. 0953, HQCD; Jim Hall, Live!, Horizon/A&M Records/Universal Music Japan, UCCM-9225, CD.; Suzanne Vega, Close-Up, Vol 1. Love Songs, Amanuensis Productions/Cooking Vinyl, COOKCD521, CD.


A review of any versatile system composed of various parts is no easy task. To make good I followed the following task list:
  • test of GT40 as a headphone amplifier via the line input
  • test of the GT40 as preamplifier
  • test of the GT40 as USB DAC with line preamplifier (+ power amp)
  • test of the GT40 as MC phonostage and line preamplifier (+ power amp)
  • test of the GT40 with  Dynaudio Focus 110A (and Furutech GT2-B).

As headphone amplifier: As always the outcome of a headphone amplifier audition depends heavily on the headphones chosen. In my opinion this dependency is even more pronounced than that between a power amplifier and loudspeakers. Because I own a few different headphones with various impedances, construction details and sonic signatures I always base my opinion on some kind of extraction after using them all. However I always need a reference point first. For me here and now that's the Sennheiser HD800.

With them the ADL was clean, open and properly dynamic. It was immediately clear that the designer had no interest to imitate a tube but rather went after maximally uncolored sound wherein he succeeded 100%. I rarely encounter headphone amplifiers that would fully show up the small differences between pressings, remasters or recorded flaws. Take for example Suzanne Vega’s Close-Up. Vol. 1 where her voice clips in a few places. Whether this is due to compression during mastering or already occurred in the studio I don’t know. But I do know that this is heard as a slight hoarseness during the louder passages which flattens out the voice. This is not always unanimous and gets lost within other issues of a playback device. Here this was not the case  Everything was clear and certain.