Originally Posted by kkl10
I've been searching for a nice little DAC and I'm interested in this ODAC. I've read that most USB powered DACs, and even DACs with their own power supplies, can benefit from an external cleaner power supply, instead of the dirty +5V sourced by most PCs VBus... Has anyone tried powering the ODAC with the Olimex USB isolator and a cleaner power supply? Or other cheap ADuM4160 based USB isolator? And there are devices like the AQVOX USB Low-Noise Linear Power Supply, Vaunix USB hub (Currawong says very good things of this with the ODAC), iFi iUSBPower... anyone tried these yet?
If anyone is interested in this question I raised some time ago...
I've acquired an ODAC, an Y USB cable and a 5V portable battery pack with 3Ah max output current through USB ports.
I've been comparing the power provided by the battery to the PC VBus and I can say that there is indeed an influence in sound.
I use electrical tape to cover the 5V pin in one of the A type leads of the USB cable, the one that provides both power and data flow.
With the "power-only" lead I compare both sources of power by switching between them.
The PC won't detect the ODAC with only the main lead connected to it, with the 5V pin taped, so I guess I succesfully disabled it's VBus power draw...
The difference in presentation I hear is very clear on my GMP and almost subtle on my Beyer which leads me to think that this is not going to show up in gear that lacks a certain level of transparency...
And even if it shows up it won't necessarily be an improvement, although in my case it so 'seems' to be...
With the battery power supply there's more apparent spacial resolution, soundstage gains definition and size, noticeably depht, and upper treble seems more "vivid" or at least clearer, the sound is also bit more transparent and laidback.
With the PC VBus feeding the ODAC there's a warmer presentation and everything sounds more forward, the finest spacial cues are lost. The soundstage is smaller, the bass is omnipresent and a bit bloomy which is more pleasent at times. Upper mids and treble are less clear...
The funny thing though, is that what made an even bigger difference was changing the interconnects, digital USB and analog RCA cables.
I know this is a controversial matter, I may be digging myself into an hole, but I can't deny what I hear.
Changing the interconnects between my components almost always imparts an influence in sound and the analog interconnects in particular sound very different between each other.
The difference between the first interconects I had and the ones that sound best is almost as much sonic improvement as switching from the PC line out to the ODAC... believe it or not.
I suspect this is because I was using cheapo 5$ cables and these may not be constructed in light of the norms they should follow... I don't know.
On my best sounding configuration I'm using a ~12 EUR Hama Y USB 1m cable bought from Amazon UK and a ~20 EUR Profigold PROA4200 0,5m RCA interconnect.
These cables are supposedly well constructed with twisted pairs wires, and proper shielding. They're the most expensive I have...
So there you go, this applies to me only, YMMV.
Edited by kkl10 - 2/20/13 at 3:48pm