I have Cambridge's CX series to which I have connected an In-Line filter with Sub out. The Streamer/DAC Cambridge CXNv2 is set in PreAmp mode with digital volume, RCA out via In-Line filter (Sub-Out also) to RCA analog input on the Cambridge CX-61 integrated amplifier. When I raise/lower the volume on the remote, the volume on both the CXN and the CX-61 is adjusted. at the same time. However, the Bus cables are required to be inserted. The signal to the A370 plate amp, from the Sub Out on the In-Line filter, follows so nicely up and down, when I play music. This works perfectly but maybe not the best solution, but a real Power Amp is needed.