DH-100 Update: I isolated the amplifier and still had the problem. I re-inspected the amplifier circuit and discovered I put .047 mf caps in the op-amp circuit that should have been 47 pf caps ( I think that's 100x less f). They were the only caps that didn't come in the re-cap kit I bought (my bad; oops). All it took was a quick trip to the electronics shop and a couple of minutes with the soldering iron, if you don't count the 1,000,000 hours I spent troubleshooting and test listening. I just finished testing it and it sounds awesome: is "stage" when you hear different instruments in different spots? if it is that it's got great staging. The bass is a bit understated and the highs can be too forward with pop/rock, but nothing that gentle twists of the tone control knobs won't hide. I'm so relieved to get this right; it was close to becoming an anchor. I could have never limped through this without the input I got here on Audiogon. Thanks!