Reviewer:
Srajan Ebaen
Financial interests: click here
Sources: 27" iMac with 5K Retina display, 4GHz quad-core engine with 4.4GHz turbo boost, 3TB Fusion Drive, 16GB SDRAM, OSX Yosemite, PureMusic 3.01, Tidal & Qobuz lossless streaming, COS Engineering D1, AURALiC Vega, Aqua Hifi Formula, Fore Audio DAISy 1, Apple iPod Classic 160GB (AIFF), Astell& Kern AK100 modified by Red Wine Audio, Cambridge Audio iD100, Pro-Ject Dock Box S Digital, Pure i20, Questyle QP1R
Preamplifier: Nagra Jazz, Esoteric C-03, Vinnie Rossi LIO with DHT module, COS Engineering D1, Wyred4Sound STP-SE Stage 2
Power & integrated amplifiers: Pass Labs XA30.8; FirstWatt SIT1, F5, F6, F7; S.A.Lab Blackbird SE; Crayon Audio CFA-1.2; Goldmund Job 225; ; Aura Note Premier; Wyred4Sound mINT; Nord Acoustics One SE UP NC500MB; AURALiC Merak [on loan]
Loudspeakers: Albedo Audio Aptica; EnigmAcoustics Mythology 1; Sounddeco Sigma 2; soundkaos Wave 40; Boenicke Audio W5se; Zu Audio Druid V & Submission; German Physiks HRS-120; Eversound Essence, Rethm Bhaava [on loan]
Cables: Complete loom of Zu Event; KingRex uArt, Zu and LightHarmonic LightSpeed double-header USB cables; Tombo Trøn S/PDIF; van den Hul AES/EBU; AudioQuest Diamond glass-fibre Toslink; Arkana Research XLR/RCA and speaker cables [on loan]; Sablon Audio Petit Corona power cords [on loan], Black Cat Cable Lupo
Power delivery: Vibex Granada/Alhambra on all components, 5m cords to amp/s + sub
Equipment rack: Artesania Audio Exoteryc double-wide 3-tier with optional glass shelves, Exoteryc Krion and glass amp stands [on loan]
Sundry accessories: Acoustic System resonators
Room: Rectangular 5.5 x 15m open floor plan with two-storey gabled ceiling, wood-sleeved steel trusses and stone-over-concrete flooring
Review component retail: $3'495

HPA-21 and DAC-21
Bakoon's bake-off of a bacon bomb. With this clodhopper of an entrance, you're bound to remember. Bakoon. Not a member of the Godzilla and Mothra league, they were an originally purely Japanese underground hifi brand run by inventor Akira Nagai [facing us in the right photo] which subsequently expanded to exports to go above ground for the rest of the world. This growth materialized when Soo In Chae of South Korea formed Bakoon International, contributed modernized cosmetics, took over production of the global (non-Japanese) models and expanded the internal design team.


Today a married Soo In divides his time between San Jose/California where his wife works and where he set up a small office; South Korea; and Japan where his director of engineering Keng Koe Ho, formerly with Sony, leads Bakoon's new R&D center in Kagoshima [foundation work below, with Soo In and Keng Koe left and right in the insert].


"For the past few months we’ve made a dealer contract in Korea and have been quite busy helping him and working to set up a sales and marketing base. It’s working great and our new products are getting high praises and good domestic orders. Unfortunately we couldn’t do so much international activities because the AMP-51R requires so much time during assembly (after the initial automated SMD production, the rest is done entirely by me and Ho-san). Now we’re ready for the AMP-51's international release and we have a sample set aside for you after Easter."


The nomenclature of the DAC-21 reviewed today gives it away. Its ambition aims lower than being the ultimate Shiva/Devi match with Bakoon's new $19'500 flagship integrated. For that, a cost-no-issue converter is on the books of future eventualities. The DAC-21's native stablemates would be the AMP-12R stereo integrated* or HPA-21 headphone amp. With them—or the new AMP-41/51—there's also the hitherto unexplored option of Akira's Satri link. That's a high Ω current-mode signal transmission protocol carried via BNC. It's conceptually related to Krell's CAST. For all other playmates from other brands, there's of course also a standard voltage-mode RCA connection. In fact, not having a matching Satri-link'd component, that's how I've always used our AMP-12R(CA).
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* Calling the AMP-12/41R/51R integrated amplifiers is correct insofar as all include volume control and switchable inputs. However, not only do they lack conventional preamp stages, they're not exactly amps plus passive pots either. That's because the Satri IC's gain is set with a resistor at its output. Logically, Bakoon now use a 10K Alps or Tokyo Ko-On pot at that precise juncture. It replaces a fixed with a variable resistor to alter the circuit's gain directly. "The conventional method for amps + passive preamps or just a pot uses them at the very input of the circuit. This reduces the incoming signal but compromises S/N ratio and sound quality. Altering the circuit's amplification factor instead is lossless. The AMP-51R flagship uses a MPU-controlled stepped attenuator."


Stated most basic, Akira Nagai's Satri tech revolves around a proprietary IC module with many discrete transistors embedded in ultra-wideband DC-coupled class A/B circuits. The tech savvy refer to their website to learn more. Here we'll simply say that Satri is at the heart of any product bearing the Bakoon badge. Hence it's the brand's secret sauce. You'd not expect them to spell out what goes into it so we won't even try. As Keng Koe put it whose house in Kumamoto happened to be near Bakoon's office, leading to an eventual meeting with Akira Nagai's Satri IC, "he is not afraid to think outside the box. Most amplifiers don't stray too far from traditional textbook circuits. The Satri circuit is a whole new idea. As an engineer, I tried many experiments with it and made my own Satri amplifiers. This led to eventually becoming Bakoon's R&D partner."

AMP-51R. The back panel shows 2 x RCA (voltage) and 2 x BNC (current) inputs.

From personal ownership of the AMP-11R subsequently upgraded to 12R status, I can add that Satri occupies the most advanced expression of a sonic aesthetic which in our hardware inventory begins with the Goldmund/Job 225, then progresses to the Crayon CFA-1.2. In short, it sits at the end of an arc of MHz DC-coupled high-resolution class A/B circuits. Speed and amazing purity are the main talking points. Until the AMP-51R, power never was but its now 100wpc (250 into 8Ω bridged to mono) recently rectified that. Now Bakoon is no longer just about ultimate refinement but can throw everyman power into the deal as well.