I have a couple of pairs of electrostatic headphones which require common ground at the interface box (yes, they are common inside the circuit). I'd like to find a small amp to put on my desk which is compatible with them and capable of providing a clean signal of ~50W @ 6-8Ω to meet the voltage specs.
The Tripath and Class D mini amps I have in my house all appear to be isolated grounds, probably differential output stages, so I'm not sure they would be a safe choice to drive the headphones. Measuring my units seems to show a fairly large resistance between left and right grounds. Common ground is not something that appears on the spec sheets in the ones I've been looking at (SMSL, Dayton, Lepai, etc.). Does anyone know of a small integrated amp with a volume control that would meet my needs?