stfoth, greatly informative exchange in that link. Thanks for sharing. Just to avoid any potential bit-stripping, I always keep the volume control "slider" on the app above 50% and lower the volume from my preamp for lower volume listening. I suppose the best practice would be to set the volume on the Bluesound, or any streamer/DAC, to "fixed" which is basically a unity gain and control the volume in the analog domain using the preamp. It would be quite practical if the preamp has a remote control.
P.S. In hindsight, I should have posted this under Digital. Sorry about that.