Audio Aero players, Resolution Audio Opus 21, I think some of the Cary players......this all of course depends on how much you are willing to spend and what you're looking for: I believe the Wadia players utilize a digital volume control, whereas the Opus f/ex utilizes an analog volume output. I'm not sure about the other brands. Do a search on the Gon. This subject has been discussed before at least a million times.
