Thanks. It appears that the "volume control " on the mobile app is changing the volume in the streamer through the WiFi connection. Definitely not the preamp since the volume control on the preamp is unchanged. I guess the real question is whether or not changing the volume on any device that can be controlled via WiFi, or Bluetooth for that matter, using a mobile device, is done in digital domain. This is of course completely different from controlling the volume via a remote control, e.g., infrared, etc., where the volume control is motorized and actually moves up or down.
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.
Thanks George. I couldn't quite follow the details of what you described but I get the 70% threshold. I was sort of using 50% as a bogie but will now change that to 70%. Between the (analog) volume control on the preamp and the volume control on the mobile app its pretty easy to modulate the desired listening levels.
Ironically, the entire premise of this discussion is based on the laziness to get off our butts and just change the volume. First world challenges...