Passive Preamps? Anyone?

Are you still using the Paradigm Reference Active 40 speakers? If so and I read the amp specs correctly the line in input impedance is 15k ohms. That is something to take into consideration when selecting a passive preamp. That being said the other posters have covered the gamut on the different brands. Personally I prefer the TVC models over the resistor models as impedance matching is less of an issue.

Another consideration would be the new Pass B1 buffer preamp. It is a zero gain design with a buffer output that offers all the benefits of a passive but eliminates impedance matching issues. It's listed here on Audiogon for about $875 new IIRC.

With that 15kohm inout impedance I would only go with the Pass B1 Buffer, not quite passive, but awfully close. For some reason the GON consensus seems to be that TVC and AVCs (I've owned both from Bent and K&K, as well as the Placette Active and RVC)are always better than resistor based passive. With my Cardas GR IC (very low capaitance) and Music Reference RM9 Special Edition I find the Gold Point Volume Attenuator SA1 works just as well to my ears. Plenty of soundstage, dynamics, and clarity. The technoids can proabably explain it better, but I get the sense that TVC and AVCs are also problematic, though they do provide a partial solution to impedance mismatches. To my ears, with properly matched source and amps, the resistor-based attenuators are undeniably simpler, purer, and capable of even lower distortion - but they do have to be in the "right" system for them to perform their best.

Incidently, toward the end of the above Lightspeed thread, Nelson Pass contributes schematics for a buffered passive that employs optocoupler resistors. I don't know whether he is currently selling product based on this design. My read is that sonics of the AU$500 Lightspeed passive should equal or surpass the optical volume control in the $23K DartZeel NHB-18S.

I believe Nelson Pass already posted the schematic on the Pass DIY site as well. I saw a couple built by Audiogon member Rawsonte fly out of here of late.

As Pubul57 says the rsistor based design is much simpler. I'm tempted to break out my EVS nude attenuators and give them a test run in my new set-up. I looked at the Lightspeed thread and am curious about those attenuators as well. Anyone know a way to contact the manufacturer?

He keeps a low profile; emailing him through that forum is probably the best way.