Passive preamp and biamping

Just to emphasis a valid point already made twice, with a passive preamp you're just throwing some of the signal away (letting it go to ground without going through the power amp) and throwing less of it away, or even none of it, can't possibly be a bad thing. In a series stepped attenuator, a high setting puts the "hot" signal through less solder joints than a lower setting, but does the opposite with the part of the signal that's getting thrown away. So maybe a higher setting is better, though I don't know enough to say. Moral: don't use a series stepped attenuator in a passive: it saves money but hurts transparency and detail badly, in comparison with a ladder type stepped attenuator or a shunt type. IMHO.

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.