Dear Sir,
For the NFB17.2 , the better power supply for the PC will have a little improved.
If you have disc transport, you can compare the sound between USB and the CDP SPDIF output.
The TE8802 with a good PC, sound will near around USD1000 CDP.
If the TE8802 sound much worst than the USD1000 CDP, you can try to upgrade a good power supply for the PC.
We don't like the isolation in the USB input. So our products have not isolation on USB input.
Kingwa