Our shiny white Audio Physic Codex 4-ways were powered by Ivo Linnenberg's 1MHz Allegro mono amps. EJ Sarmento's very best Wyred preamp handled precision balanced volume and fully balanced and buffered signal routing. This hardware combo set system resolution as high as our options allowed. If the Koreans made a difference, I'd hear it. The USB cable from iMac to SOtM was our usual red KingRex double-header uArt. This would also feed the Formula DAC direct. Connecting SOtM and DAC was a Curious leash. That cable and SOtM's reclocking plus noise reduction circuitry would be the detour loop of the extra signal path.

Using premium fare like ECM's Achirana, a piano trio setting with Vassilis Tsabropolous; and standard fare like Wael Jassar's second Fe Hadret Mahboub installment; the verdict was literally clear. Direct had it. Huh? The optocoupled Formula DAC really was immune to upstream USB massages. By contrast, additional circuitry and connections now behaved as though minorly lossy. To be sure, this was a subtle difference. It was most apparent in the treble, separation and ultimate tone textures. If I had just one word, I'd use clarity. I thought it very much to SOtM's credit that in this contrarious scenario, extra cabling, two more connections—let's face it, the USB standard isn't the snuggest—and sundry circuit traces and parts where this transparent. They only left a minor fingerprint smudge. In a high-resolution context, I just noticed that. It called the simpler solution superior. Clearly it wasn't broken. It wanted no fixing. So the Italian formula followed Elvis out of the building. Fore Audio's DAisY1 with hybrid tube buffer became his impersonator.

As so often is the case, the impersonator wasn't as good as the original. This left room for SOtM's twosome to go to work on Fore Audio's Amanero Combo384 transceiver. This became a quasi rerun of the above, just in reverse and with a larger gap. Now the detour was the more lucid, articulate and present. Direct felt slightly 'muffled' and, on gestalt not actual metres, the more distanced or removed. On Méditerannées, Renaud Garcia-Fons' mighty 5-string upright had the more evolved tone textures and more incisive bouncing-bow spiccatos for better percussive distinction. This improvement really equated to the digital transport domain of yesteryear. Then folks were surprised that, what effrontery, a C.E.C. or Esoteric or 47lab PitRacer transport sounded different than a Sony or Denon.

Back to my A/B, the improvement didn't operate on soundstage width/depth, placement, image size or similar. Rather, the best pointer would call out the surfaces of individual sounds. Those felt stripped of fuzz, blur and opacity to shine freely without any reluctance or intermediate buffer. One might call the result more quicksilvery, the other version slightly sleepy-eyed by comparison. Driving Miss Daisy on the detour made her less genteel and more feisty. Go girl! The difference was related to a power cord swap during a recent review; from a copper Acrolink on the source-stack conditioner to a Titan Audio mono-crystal silver. The latter then had had a SOtM-type effect but wanted €2'500; nearly double. With an espresso, that's exciting. With a wallet, not so much.

With the Koreans' efficacy settled, it was time to dig into the contributions of just the linear power supply. My petit but shiny contact Mary Park at SOtM, after being asked details about it, had requested that I first form an opinion. Then she'd happily explain its innards. It really only took one comparative track to hear the effect. All subsequent tracks just signed the same bill. In short, with/without linear power was more pronounced than comparing the wall-warty SOtM to direct mode. With the switcher, the sound incurred a slightly grey pallor. With the $550 supply, colours cast off that 50-shades-of-grey filter and grew fully vibrant again. That was the essence of it. Granted, for half a grand, greedy punters might want more than just a sentence or two. Then it might be helpful to give them an imaginary saturation slider for an image that starts out black'n'white. Slowly ramp up that slider. Things progress from pale and gauzy tints to richer values. Halfway before you hit max full colour is the zone of the wall wart. Full tilt or tint means linear power. To this one must add a sense of higher dynamic scaling. The beneficiary is the same: intensity. For me, the outboard power supply worked on higher colour temperatures and more robust dynamics. Going without it meant throwing away performance which the tx-USBultra held back. Because I had it on hand, I next compared SOtM's twins to Audiobyte's battery-power Hydra X+. This outputs on S/PDIF and AES/EBU, the latter my preference. In this A/B, the €699 Romanian addition was drier and more damped, the Korean juicier and more buyant; a mostly sideways move. Where I liked the former a lot better? Integrating all necessities in one box. SOtM's two-box approach with umbilical felt rather less elegant and audiofool kludgy. It also cost double. Still, many would prefer its sonics. As to using a throwaway USB cable on the first leg, don't. It did act like a boa constrictor. I'm not proposing a 'gold-plated' silly-money variant. Just use something a step or two up from crap.