JCAT's Optimo 3 Duo measures 195x395x85mm WxDxH, weighs about two kilograms and sits on four trapezoidal rubber feet. Its thick black aluminium forehead with all edges nicely trimmed features one small horizontal groove with the  name, a green LED and the JCAT logo underneath. One heavily perforated non-magnetic U-shaped steel sheet forms cheeks and top. The business end houses two locking Neutrik' speakON SPX DC outlets and a Furutech IEC inlet with self-replaceable Furutech fuse.

The Optimo 3 Duo's plug'n'play nature renders switches, buttons and knobs unnecessary. Even on/off was ditched. Once connected to the mains, its LED indicates readiness and that's it. Just attach provided power umbilicals to suitable DC-powered devices and you're good to go. Looks are utilitarian, build is nicely robust, operation at best mildly warm during usage. The fully separated DC outlets can feed two different products at the same time with no loss of quality. Upon order time a customer specifies the power input (115/230V) and each outlet's output voltage. Although 5V/3A is the default, options extend to 9 and 12V up to 3A of current. Mix'n'match is allowable. One socket may provide i.e. 5V/3A, the other 12V/3A. The two fine cables will have their ends adapted to your hardware. Marcin's awareness of various needs is clear.

As did the recently reviewed Innuos PhoenixUSB, today's innards don't look like much. It's a linear design free from switching power and doesn't need a lot to work. Its custom 100VA power toroidal inside a magnetically/electrically shielded cowl seals with epoxy to reduce vibration and and sits on a steel plate mechanically decoupled from the enclosure's bottom via rubber pucks. Each supply board features six LT3045 linear voltage regulators fixed to large radiators. The same number of Nichicon 3'300μF Fine Gold caps provides filtering, Schottky diodes are rectifiers of choice. The Optimo 3 Duo's description informs us about DC voltage noise below any measurable range, i.e. sub 2μV.

For the Telegärtner part of the gig, two separate boxes housed the switch and two non-standard Ethernet cables. The boxes looked ordinary but once open, faux gold silk framed the M12 Switch Gold which struck me as funny considering this product's mostly invisible role behind a rack. This kit required no extras so not seeing any didn't surprise. The lack of the usual switching supply simply restated that Marcin wanted me to use it with his Optimo 3 Duo. [How did this facilitate an A/B comparison to the stock supply one wonders? Ed.] The M12 Switch Gold measures 7x20x5cm WxDxH and weighs 1.5kg. Although petite, it feels substantial. Its mildly polished die-cast aluminium enclosure in bronze finish was designed to withstand harsh environs from -40°C up to +70°C, avoid internal condensation during up to 95% humidity and shield against EMI/RFI. If you're wondering about the circuitry within, no soul outside Telegärtner's Japanese plant knows, not even Marcin. A specialist low-noise industrial-grade mini computer optimized for active network switching would be my careful assumption. Whatever it is, I was told that it's very sensitive to vibrations, thus for optimal results decoupling from the floor is strongly suggested. Since my rack had enough space, I happily obliged.