On 10/03/2014 16:49, Jim Lesurf wrote:
In article , Eiron
wrote:
On 10/03/2014 15:15, alexd wrote:
Jim Lesurf (for it is he) wrote:

Oh, and measurements show the choice of USB hub+psu can indeed affect
audio performance to a measureable extent.

Obviously you want a gold-plated power connector on the hub.

Or a Russ Andrews usb psu with yerrite beads. Yerrite? That's the
correct response when he tells you how it works, or what it costs.

Actually the main effect that made me notice was that one hub + psu caused
both a low level 485Hz tone *and* modulated a test sinewave to have 485Hz
sidebands. I presume these are AM due to the device's ADC having this
ripple on its 5V (sic) output. A change of hub and psu and I found one
where this effect vanished.

I don't think either hub or psu cost more than a few quid. The effects were
low level. I probably wouldn't have noticed them with 16bit samples. But
they showed there are some gotya's lurking if you are after high
resolution.

No gold was harmed in the making of these tests. :-)

Jim


Just to make your blood boil:

http://www.theguardian.com/technolog...usic-converter

or https://tinyurl.com/q8ju7p9

Incidentally, can you *hear* any difference between all these DACs?


--
Cheers, Rob