Most manufacturers are adding USB interfaces to their DACs now without much experience with these. As a result, most of these DACs sound better driven from S/PDIF input rather than USB input.
The other thing to realize is that even the very best USB interface when install in a DAC will likely share some part of the power system, ultimately compromising it.
The best course is to buy the very best outboard USB converter and then power it from the very best power supply. This will definitely beat even the best transports on the market. There are some companies that are shipping 5th generation of these interfaces.
The other thing to realize is that the player software and computer hardware is critical. I recommend Amarra on a 2009 Mac Mini powered by a Hynes power supply playing .wav files. Nothing touches this IME.
Steve N.
Empirical Audio
The other thing to realize is that even the very best USB interface when install in a DAC will likely share some part of the power system, ultimately compromising it.
The best course is to buy the very best outboard USB converter and then power it from the very best power supply. This will definitely beat even the best transports on the market. There are some companies that are shipping 5th generation of these interfaces.
The other thing to realize is that the player software and computer hardware is critical. I recommend Amarra on a 2009 Mac Mini powered by a Hynes power supply playing .wav files. Nothing touches this IME.
Steve N.
Empirical Audio