Tried the ATM-3's recently in my 'A' rig- didn't do it for me (bass too thick and a bit slow, and transparency could be better) HOWEVER, picked up the smaller ATM-4, and it's fantastic! Much better PRAT, and better transprency as well, I also found the decay of the note superior, as well as the superior 'delicacy' it brought to the table. It is a vey organic and involcing amp you can just listen too and forget about analyzing the sound. One of the two major U.S. Air Tight dealers agreed that the ATM-4 and ATM-1 were the best sounding of the Air Tight PP lineup due to their simplicity of circuit design; less tubes; however still retaining the extremely high parts and build quality Air Tight is known for. Would love to hear their ATM-211 monos...
