The problem with USB is two-fold:
1) common-mode noise on the cable that is not completely rejected by the USB receiver
2) poor software on the server device
#1 can be mitigated with filters or galvanic isolation. I have done both.
#2 can be mitigated by using a Linux-based server properly configured with good playback software and CODECs
Short of doing both of these, you will have some sonic issues with USB
If you do both, it will be identical in performance to Ethernet renderer, assuming both are implemented similarly. Implementation is everything.
Steve N.
Empirical Audio
1) common-mode noise on the cable that is not completely rejected by the USB receiver
2) poor software on the server device
#1 can be mitigated with filters or galvanic isolation. I have done both.
#2 can be mitigated by using a Linux-based server properly configured with good playback software and CODECs
Short of doing both of these, you will have some sonic issues with USB
If you do both, it will be identical in performance to Ethernet renderer, assuming both are implemented similarly. Implementation is everything.
Steve N.
Empirical Audio

