A passive sort of guy?

[bensim09]

My passive is a dave slage autoformer type, I’ve play a few time with the internal inductance gap adjustement to tune the sound to my liking (and I’m still amazed of the difference it makes). So to think that passive is transparent by the fact is passive is not correct. Resistive and autoformer have their own negative impact on music reproduction.
My passive is very good and better than active in several area but clearly lack drive especially at high volume, you start to feel compression, everything sound flat, lifeless. My feeling is that the output stage of my DAC/CD player is not able to drive properly the amp because of an impedance mismatch.
A good active preamp (I have solid state one with an external and super quiet power supply) is able to give more drive without losing details and spaciousness.
To be clear, passive is very system dependant and should be tried but I can’t help thinking that a very good active preamp is certainly the way to go to have ultimate performance.

 

[Tony L]

I'm currently listening to my upstairs system, a Marantz SACD player, Audio Synthesis Passion, Leak Stereo 20 and JR149s. The Passion is a new addition, it is the high spec Vishay variant that uses a fancy Z-Foil shunt resistor, it also has a 'direct' input that bypasses the input selector. As such my "preamp" is a Z-foil in the signal path and one very nice switched Vishay resistor to ground per channel. That's it. I don't see how that can possibly be beaten with an active preamp given the Leak has an input sensitivity of 125mV and an input impedance of 1mOhm! All I'd achieve is to add noise and distortion. It sounds seriously good, noticeably better than the preceding PAS-02 (an input selector and four nice resistors in the signal path as it has a fancy dual-gang attenuator for very fine-adjustment). The PAS-02 was my reference point until very recently!

 

[Paul R]

I think transformers should be considered (and discarded) separately, they are intended to solve a problem that should be solved elsewhere and introduce a whole swathe of real distortions as a consequence.

Tony's arrangement is nearly ideal*. If you are digital only then a digital attenuator right in the DAC followed by the output driver you have to have anyway is best.

Paul

*In practice that's the same as perfect. Especially into a (relatively) noisy power amp, and/or from vinyl.

 

[Neilsan]

I've been using "passive" pots for years with no problems Latest one I'm using is an LDR kit from this guy.
http://www.buildanamp.com/Clone-Note-aka-Lighter-Note-rev-4-CloneNoteKit.htm
Only one LDR in the circuit and it "sounds" marvelous. No problems with cd or phono stage,tapedeck,etc driving my Perreaux 2150b or my Radford STA25/3 or as Tony mentioned, my Leak.Only problem is it's so clean that on the odd occasion I could do with more "volume"!