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This review first appeared in the August 2011 issue of hi-end hifi magazine of Germany. You can also read this review of the Esoteric I-03 in its original German version. We publish its English translation in a mutual syndication arrangement with the publishers. 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 fairaudio or Esoteric - Ed.

Reviewer: Ralph Werner
Sources: Analog -
VPI Scout II, SME M2 12-inch, VPI JMW 9T, Denon DL-103, Ortofon MC Rondo Bronce,
Zu Audio DL-103, SAC Gamma Sym – digital - Luxman D-05, Logitech Squeezebox 3, Readynas Duo NAS-Server,
HP Notebook, Benchmark DAC1 USB
Preamplifier: Octave HP300 with MC phono
Power amplifier: Electrocompaniet AW180
Integrated amp: Denon PMA-2010AE
Loudspeakers: Ascendo System F, Thiel SCS4
Various accessories, cables and racks
Review component retail: €9.499.

Fat D! The Teac/Esoteric word combo surely elicits instant visions of tank-like CD players. And that’s very factual. It’s what the Japanese are best known for and continue to offer. For top crop machines, even competitors go to the Esoteric well for the legendary VRDS sleds. Think Paganini transport by dCS, Playback Design or Audioaéro’s luxury deck La Source. To each case belongs a sticker Esoteric inside. But clearly no insider knowledge is needed to predict an uncertain future for any firm that would specialize solely in expensive to ultra-expensive SACD/CD players.

Years ago Esoteric thus already branched out into various D/A converters, then became a complete front-to-back provider with electronics, loudspeakers and cables. The current catalogue includes two stereo power amps, a pair of class A/B monos, a preamp, a phono stage and today’s contender, the Esoteric I-03 integrated amp which combines the C-03 preamp stage with new class D power modules designed especially for this machine.

Contrary to the previously reviewed AI-10 as the firm’s first class D effort and sadly discontinued since, the new I-03 positions itself in an area usually reserved for mature pre/power separates. But ‘usually’ is perhaps a bit old-fashioned given that expensive super-ambitious integrateds no longer are as rare as they were perhaps 10 or 20 years ago. Clearly Esoteric’s latest is an unapologetic luxury attempt. That makes the design team twice as courageous for embracing class D power which many listeners still view with barely disguised suspicion. I frankly find such reactions peculiar.

True, clichéd warfare between various religious factions committed to favored solutions—analog vs. digital, tube vs. transistors, evil vs. benign feedback—has been endemic to the high-end for seemingly ever. It’s no surprise that class D amplification should be exposed to serious disagreements about its worthiness too. Beyond argument is simply the far higher efficiency of such circuits. Whilst traditional class A/AB architectures throw away 50% to 80% of consumed wall power as heat, switching amplifiers reduce the same wastefulness to between 10% and 20%. The upshot is obvious. Equal output power becomes possible with far smaller power supplies. Likewise for seriously scaled back cooling solutions. These two items reflect directly in cost savings for both manufacturing and shipping relative to size and weight. The price advantages of lower weight at least theoretically also suggest higher value. So much for theory and class D. Then the Esoteric I-03 arrived. On a euro pallet.

Apparently the Japanese got confused over the concept. The amp’s packing alone weighs close to 10kg, i.e. noticeably more than the pair of NuForce class D monos we reviewed in 2008. The amp itself weighs 31kg. What gives? The outer casing is a first indicator by practicing not merely Scandinavian design restraint and superlative finish but material generosity. The fascia is thick as a fat thumb though the elegant bevels do minimize the visual impact. The rounded front corner pieces further undermine cosmetic boxiness but add mass. Ditto the 5mm base and 7mm cheeks which double as heat sinks. Likewise for the 5mm cover with the brand's engraving. The I-03’s enclosure is truly massive. Popping the bonnet adds more reasons for the weight. Thankfully I earlier only said class D power supplies may be smaller. They clearly needn’t be.

The innards here are subdivided into five chambers for specific functions. The Japanese explain that the layout is highly deliberate to reduce mutual interference between building blocks whilst shortening the signal path. The two preamp boards—a 2mm steel plate separates the channels—thus mount directly to the rear panel since that’s where the inputs live. Except for the single power transformer, the I-03’s circuit is built up fully dual mono.

The central and massive transformer behind the fascia resides on its own steel plinth to channel possible mechanical vibrations effectively into the bottom panel and from there into the patented footers to combat microphony. The casing surrounding the trafo blocks stray fields from intruding into surrounding circuitry. Integrated into the baffle with its own fully enclosed metal sleeve is the dimmable/extinguishable display and overall steering logic circuitry. The power supply for this module is shielded as well to eliminate microprocessor noise from intruding into the amplification path. The two lateral bays contain the class D output stages which are mounted vertically for maximal thermal conduction into the beefy chassis cheeks.