No, you're not bypassing the volume control. And the bypass function is so easy to control from the remote (rather than getting up to change the tape loop setting) that it seems to be the way to go (b/t preamp and amp).
I wrote to the manufacturer and they indicated that the cleanest way to use the unit was to keep it in the digital domain (i.e. put it between the digital signal and the DAC) or to use it as a DAC/preamp itself with no other equipment before the amps.
FYI - the USB input jack is a mini - so it's not like many USB DACs we are used to. This would entail either an adaptor or a USBA to mini cable.
I wrote to the manufacturer and they indicated that the cleanest way to use the unit was to keep it in the digital domain (i.e. put it between the digital signal and the DAC) or to use it as a DAC/preamp itself with no other equipment before the amps.
FYI - the USB input jack is a mini - so it's not like many USB DACs we are used to. This would entail either an adaptor or a USBA to mini cable.