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Reader Ted Brady: "As I noted on a couple of forums I either moderate or heavily contribute to—Audio Circle, Computer Audiophile—the notion of cleaning up nasty 5V USB power is one I wanted to tackle since my costly and musical Meitner MA-1 lives off this USB power, dirty or not. So I have several options using my Win 8 minimalist music server (dubbed CAPS v2+ in Computer Audiophile nomenclature) that runs the wonderful-sounding smaller SOtM PCie card. These are listed in order of likely delivery and theoretical cleanliness:
Acoustic Revive dual-conduit cables with dual or single termination

• Jesus of Sonore US (SotM's domestic distributor) sent me the AC-charged intelligent battery option mBPS-d2s you just previewed. Simple, clean, no need for additional USB cables or connections.
• iFi's USB power kit uses a generic USB cable to get signal+power to the iFi power supply. The ifi then allows for a dual conduit power leg and signal leg or the standard power/signal in the same lead. I will test the latter with my current Wireworld Platinum Starlight.
• I will test the former (signal+power) with a dual-conduit Acoustic Revive USB 1.0SP cable on loan. Since I have the PCie SOtM card with only one USB output, I currently can't demo this dual-conduit cable any other way.
• I may try and dial down my Hynes SR3-12 (Paul thinks I can only get it to either 8.5V or maybe just 10V) and use it in place of SOtM's battery power - but only if I can get assurance that it will do no harm. This solution is doubtful.


"I know there are other solutions—Aqvox, other dual-conduit cables etc—but my head may explode by then. Frankly, I couldn’t imagine a blacker background than I was getting from feeding the Meitner dirty mobo power regardless of the clean linear Hynes overall power (the mobo took my Hynes SR7 linear power and added its own dirt to anything it powers). Well, here it’s a no-brainer. The SOtM battery power plugged directly into the card and left unchecked (I am a goof ball when it comes to remember recharging batteries) is quite revelatory. As I said earlier, my soundstage and overall presentation had already been magically musical with a very black background. Well, make that a dark gray background now since the battery power redefines black!

dX-USB HD, optional board uninstalled for proper viewing

"I use subtle recordings—bombastic Rock recordings don't really bring this forward—like the micro cues in the Cowboy Junkies' church recording The Trinity Session. I know this record as well as any and listening via battery USB power was revelatory. Ambient cues and microdynamic shadings came through as never before as though I was hearing it properly remastered in 24-bit or DSD. It actually floored me as I wasn't expecting such an already low noise floor to go that much lower. Again, this wasn't evident on some music but clearly on the quietest of passages. And this lowering of noise has great effects on bass musicality too as everything seems tighter and better controlled. I can't go back to mobo-induced power now. I think this SOtM battery supply is such a simple and elegant addition to the great musicality of the CAPS V2+. Can’t wait to try the other solutions but this—so direct, simple and inexpensive—will be tough to beat."

Ted's excitement tracked my own when I'd first discovered how bypassing the hiFace2-based OEM module inside APL Hifi's NWO-M DAC with the USB-powered Audiophilleo 2 improved things; and how they moved up another level once the latter was powered from Bakoon's battery supply. Ted's MA-1 converter sells for $7.500. His feedback confirms my earlier statement. At times even very costly converters can benefit from SOtM-style add-ons. This depends on how they power their USB input—from the computer or (as Metrum's Hex does with its hiFace1-based OEM board) from their own linear power supply—and how good and low-jitter their chosen transceiver is compared to an external USB bridge.