Hello Cwlondon, all volume controls including digital are not created equal. Digital volume controls literaly throw away resolution as they attenuate, although dynamics seem to be untouched. Analog depending on the quality seem to retain resolution but dynamics can suffer so it would seem on the surface you may as well toss a coin. I've also used passive attenuators which you can try between your Dac and Amp, some prefering TVC types over RVC attenuators.I had an interesting coversation with John from Bent Audio, he told me if you use both digital and analog attenuators at the same time each padding down the signal and operating toward their upper limits where both loose the least and operate at their best. I do this myself and find it's better than either attenuator types used on their own and dynamics timber and harmonics are preserved. I also see you are restricted to 20 bit because of your Dac of choice, upscaling both bits and frequency will give your digital volume control somthing to loose and retain more bits. I use Saracon or r8brain, the latter is free and easy to use.Please be sure your SPIDIF cable is 110 ohm , DH Labs make a good one for reasonable money but I know there are many others. I hope this will address at least part of of you needs.
