I use my SBTouch in conjunction with an MDAC, connected via USB...

My original setup required a USB hub, as I recall a hub was required for certain DACs, the MDAC being one...USB1/2 conversion

Subsequently I added an iFi USB Power, and more recently an iFi Purifier 2 ahead of the USB Power.

I've been getting some connection dropouts since introducing the Purifier 2, occasionally when turning on another device connected to the same TACIMA gang the connection drops...I'm getting some better 6 way gangs from MCRU, as there is another user experiencing a similar issue, and they use TACIMA too.

That aside in attempting to debug the issue I removed the USB hub, and it connects perfectly to the MDAC, via the Purifier 2...I suppose this makes perfect sense as it's a USB re-generator amongst other things...so it's providing the connectivity, improving the sound, and simplifying the clutter behind the Touch too...

I don't know if the USB Power alone would provide this capability, I've not tried it, but the USB 3.0 should provide this, as it has the purifier 2 built-in as it were...

Presumably other re-gen devices would offer similar functionality...