Granting the wisdom of Mikelavigne and Redkiwi on the desirability of (1) keeping interconnects from a passive short, and (2) having high input impedance in the power amp, one experience of mine would indicate that these principles should be seen as rules of thumb, not as written in stone. I used a 10K ohm passive with 8' interconnects into Pass Aleph 3's used as monoblocks, with inputs and outputs both paralleled. That would make the power amp input impedance 11.5K ohms, if I recall correctly that the Aleph 3 lists its input impedance at 23K ohms. Its gain is only 20 decibels. And I didn't notice lack of body or thin bass, though I was using the Aleph 3's with Quad ESL 63's, no deep bass at the best of times. When I told Nelson Pass that his Aleph 3's worked with a passive preamp, he said my experience had been reported by other Aleph 3 users. Do we all have tin ears? I don't rule out that possibility, at least for myself, and I'd certainly go by the rules of thumb if I had a choice. I wouldn't choose gear that violated those rules. But if I had it on hand anyway, I wouldn't hesitate to give it a try.
