|... We still haven't learned from you which impedance setting you made at the amp when listening to each of your cited headsets...|
Instead I will try to borrow a Beyer DT880 or similar in either 250 ohms or 600 ohms. Anyone care to send me a pair?
Rob, the Elekit does work very nice w/ low impedance cans (currently listening to a Denon AH-D5000 w/ MarkL mods and Bubinga Cups). Another amp which IMO sounds great w/ Grado is the Mapletree Ear + Purist HD or the PinkFloyd Modded Musical Fidelity X-Can V2 or V3.