This review page is supported in part by the sponsors whose ad banners are displayed below
The eight 'super' chips naturally have their identifying markings erased to protect intellectual properties.
Experiencing a Kusunoki-style non-oversampling and filterless DAC which was not executed with the ubiquitous 1980 Philips but instead a 21st-century R/2R chip from the non-audio sector... heck, that was
quite the rare opportunity and certainly not one I'd been offered before. What curious audiophile worth his suspenders could possibly pass it up? Yes was thus the only legitimate response.
The Octave model changes the enclosure dimensions of the company's first smaller NOS Mini DAC implementations and migrates into two boxes. The external power supply comes in two flavors, 7VA single toroid or heavily filtered 14VA dual toroids. Both are switchable between 115/230V.
"Very fast glitch-free" rectification, dual-mono regulation through eight low-noise ICs and power supply smoothing and ripple suppression via a boffo 12.000μF filter bank of 26 capacitors take place inside the converter for a very classic dirty/clean box approach. The power umbilical uses quality spring-lock connectors.
The 75Ω coaxial input is limited to a maximum data sample rate of 176.4kHz, the Toshiba optical link limits at 96kHz. The line output is an industry-standard 2Vrms or 5.7V peak to peak. Slew rate is 35V/μS, jitter less than 40ps. THD is better than 0.04% and noise -130dB relative to full-scale output. Output impedance is 82Ω. Dimensions are 30.5 x 103 x 240mm, weight for both DAC and 14VA PSU is 1.3kg.
"These chips were designed to drive 75Ω loads so there's no need for any output buffer. In the Octave you have 4 chips per channel working in parallel. 8 chips total are connected by eight 330Ω resistors to create an output impedance of 82.5Ω. The other four chips at the end of the board meanwhile handle the digital input and glue logic to match the octet of dacs whose outputs —coupled directly to the output RCAs via those resistors—are routed between the six layers of the PCB to the edge of the board. That part was easy. To work my way through all available chips took almost two years however. All of them were matched to this circuit and worked properly yet only one sounded terrific and completely different to all the usual silicon. I think you will notice the stress-free core gestalt of this machine after only a few bars. Be aware that the sound initially is bright and requires about a week to settle down and about 3-4 weeks of play to mature fully. But even out of the box the essence should communicate itself clearly."