Great response from Poorguy--it leaves me speechless. Well, almost. You'll find a few people, dealers mostly, who claim that best potentiometers beats best stepped attenuators of any type. But I think most experts would vote for ladder type stepped attenuators, in which there is a single series resistor and a single resistor to ground at each setting (as opposed to series stepped attenuators, in which there are roughly as many resistors, series and ground, as there are steps, so a lot of solder joints for the signal to pass through). I've made both series and ladder, both using Holco resistors and excellent switches, and can easily hear the superiority of the ladder type. Still, some very prestigious preamps, like at least older ARC and all the CAT's, use a series type. That's one reason why I sold my CAT SL-1 III, despite its having a factory-simplified signal path: it was much less transparent than a ladder type passive preamp I made myself. Whether a passive or active preamp is best is another contentious issue. But in any preamp using a stepped attenuator, I'm prepared to say without fear of contradiction (or at least I won't be moved if someone does) that ladder beats series by a country mile. There's a shunt type too, which I've never heard. Unlike all the other types, it presents a different input impedance to the source with different settings.
