Sounds like a loose wire. As much as I love my ASL headphone amp I think the quality control is suspect. Check the soldered connections inside. You might find a loose solder or wire.
ASL Head Amp
I recently bought a headphone amp (Antique Sound Lab MG-Head DT) off of here. But I'm thinking about selling it. I have had an annoying, loud level of hum out of every one of my headphone (Grado SR-60, AKG 271, Audio Technica ATH-AD700). I've changed the Tubes, added Herbie's Tube Dampers, changed the inputs I use and the type of power cable (grounded to ungrounded) and most everything I can think of. Which is admittedly limited. So before I relegate this thing to the closet or the pawn shop, is there anything else I can do?
Any help would be appreciated.
Paul
Any help would be appreciated.
Paul