NOS1 USB vs Berkeley Alpha + Lynx AES16

[easternlethal]

ah i see. a few more questions if that's okay (please don't feel like you need to disclose anything you don't need to):

1) what usb chip does the dac use and is the driver programmed from scratch or based on some conventional standard like the vhpd1394? how do you avoid the noise in the usb signal from the beginning?

2) how do you convert the usb to i2s?

[PeterSt]

Let me try to be as vague as possible ...

There's a CS receiver and a Xilinx FPGA.

Driver was not programmed from scratch (who the h*ll do you think I am ? ), BUT, the source code was licensed to me. So, quite a few things are now proprietary to Phasure.

The noise is "just" a matter of wanting to avoid it, and next tweak as long as it takes to achieve that. Of course this is a way too simple explanation (as a matter of fact, it isn't at all), but what's the most important is that one (me) needs a reference to hunt down. To this regard I can tell you that in attempt to coorporate with other engineers in this (USB) field, I found no luck because "I shouldn't be doing difficult because any noise under XYZ would not be audible anyway".
That this relates to jitter specs is just that tad of knowledge where things can get better than in other random situations. Like I said in the before post : it is the combination of things which make it work.

Couldn't be more vague !
Peter

[TonyB]

Not true, you could be more vague 

It is interesting that you could bring noise down without isolation. If both the computer and DAC ground are earthed, there is a gound loop and some garbage signal will flow on this wire.

TonyB

[PeterSt]

While true, groundloops can be broken ...
Hint : this is all part of the DC Offset Control in the NOS1 ...
(which is without any circuitry for/against it)