Then in 2008, young passionate audio engineer Soo In Chae was working for a nano tech company and had plans for a PhD in industrial engineering. He was listening to Nagai's AMP-5513 of the day whose innovative technology and sound quality fascinated him. The two eventually met, Nagai wanted to go global, an inspired and tech-savvy Soo In came aboard and Bakoon International established in Seoul a year later. Models based on the SATRI circuit became available globally and visually modern industrial design and mechanical engineering Soo In's full-time job. All export Bakoon models are styled by him and he also handles marketing.
More recently Bakoon opened a new R&D center in Japan's city of Kagoshima while Seoul's HQ is scheduled to relocate fully to Silicon Valley during 2019. Manufacture will remain in South Korea. Former Sony engineer Keng Koe Ho joined Bakoon International as CTO several years ago. Their business seems to boom, with one DAC and three new amplifiers introduced over just two years and today's AMP-13R the very latest. Finally, the company's name is a contraction of 'Baku' and 'Un', signifying 'lucky dream' whereas SATRI derives from the Japanese 'satori' for enlightenment.
All Bakoon models are known for exceptional visuals, compact sizes and power measured not in the hundreds but dozens of watts to recall the now discontinued AMP-11R. It established the company's position on the global market, made Akita Nagai's achievement famous and it's been onward and up since then, with things in the Bakoon camp anything but stagnant. 6moons published reviews on their AMP-51R (100wpc, $19'500) and AMP-41R (50wpc, $9'000), signaling clearly bigger more powerful Bakoon amps than anything we'd seen before.
Since those two models aren't exactly affordable, today's $5'800 model occupies a more wallet-friendly space a fair bit below. One might thus assume that this mini machine fell victim to downscaling and brutal trimming. But really, the AMP-13R addresses demands by enthusiasts who need less power whilst exploiting the same solutions established already for the bigger models. Squeezing higher efficiency from the AMP-13R's far reduced form factor then led to a circuit discovery which proved to be so brilliant that it will now find its way into their upper echelon models. A new bias management system tracks and compensates for thermal shifts in the output transistors within miliseconds regardless of load. Though this might sound trivial to implement, their description says otherwise. ADC, DAC, MPU and custom firmware are all involved. The upshot is fewer parts, shorter signal paths and increased power efficiency. A new power supply eliminates the earlier output stage emitter resistors to lower output impedance for a more direct response and the new bias controller even eliminates the usual warm-up time, optimizing the output transistors' load line instantly.
Given the innate speed of this circuit, SATRI has since been renamed JET SATRI. The AMP-13R measures just 230 x 230 x 55mm (WxDxH) and weighs only four kilograms to become the smallest stereo integrated I've ever handled. Its 25wpc/8Ω rating is for people fully aware of how much power they really consume. Bandwidth spans 10Hz to a whopping 500kHz. Gain is 22.5dB for speakers and headphones (high), 7dB for headphones (low). A MPU-controlled attenuator of 50 steps sets the amplification factor. Input impedance is 3.68Ω for the current-mode inputs, 10kΩ for the standard voltage inputs. Max power draw is 100 watts.
The enclosure is machined out of solid sandblasted aluminium and its fascia height of just 2.7cm is most intriguing. This pancake stores all necessary innards and exhibits five multi-purpose pucks on its hard underbelly. Three of those are several millimeters taller than the other two to become support footers. All of them double as heat sinks and the largest one not serrated into fins contains the toroidal power transformer. The asymmetrical placement of these five protrusions might appear random but is in fact most strategic to serve thermal exchange, mechanical stability, resonance control and to my eyes also greatly ups the visual ante. This very clever packaging allowed Soo In to get by with the most compact minimalist optics. The front sports the brand logo on the left, input selection diodes (V1, V2 and SL) next, then an IR receiver and the endlessly rotating gain knob aka volume control interface dead center.