@ClieOS Is the digital volume adjustable on M1 when using it as a transport?
Depends on the USB receiver chip's setting on the DAC/amp. As far as I can tell, M1's digital volume works on HA-2 (which we do know will allow digital volume control on source, as part of its design), but has no effect on Mojo or micro iDSD.
You not got a choke on your USB cable?
Don't see the point, especially at this length,