Passive pre-amp any good???

A passive preamp will work fine with many systems.
The only problem with some system using a passive preamp is the current drive of the original source component is insufficient to properly drive the amplifier.
The electical signal comes out ot the source component and has a certain complex combination of voltage, impedence, load it wants see, and amperage (small, but meaningful)
The passive preamp really just passes along the signal, just cutting it down with the volume control, to the amplifier.
If the signal isn't able to drive the amplifier properly, the sound is "thin" or shallow.
That is the one sometime flaw with passive preamps.
The active preamp takes care of that problem, at the risk of being more veiled.
The tradeoff is which one do you want to worry about?
(For the electrical engineers: please excuse the bastardized explaination, I try, if you can explain it better, please do!)

Sounds pretty good to me!

Dave

My experience w/ passive preamps is limited. I have heard the ASL $500 xformer-based passive pre. It was driving an ASL power amp. Maybe matching was not an issue as both were from the same company?
The sound was exemplary, if I may say so! No thin sound at all.
The sound was very transparent & since I was listening to single-driver speakers (Cain & Cain Single BEN & Carolina Audio JTM) the sound was so very coherent!
I have a hard time understanding why an amp input would need a current drive! In my books, such an amp would a failure of a design! A power amp is essentially a voltage source so it's voltage in & voltage out (with high current drive). The input to a power amp is usually to MOSFET gates or to a BJT base both of which are high impedance & small signal. Current into a BJT base should be in the 1uA or less, if the beta is high (today this is *practically* guaranteed).
I'd believe you that you have heard a thin sound but I would not jump the gun & pin it to lack of current drive from the source component. It is *possible* that the passive pre hadn't broken in OR it might be possible that the passive finally revealed the true colours of the source component!
IMHO. FWIW.

I went from a modest powered preamp (Forte model 2) to using a separate phono preamp unit (benz pp1) with a passive pre unit and the difference was night and day in terms of expanded, not reduced dynamics, better and lower bass information, wider deeper soundstage, cleaner more revealed information. I would never go back to an active preamp unless it was one of those $10k plus designs (FM accoustics or something like that) it would have to rival the passive. Only thing with the passive is that you cannot get that extra very high volume (if you want to play loud rock) but that can be overcome with efficient speakers. ( I have a pair of Jbl L-200's for that purpose)

P.S., the airtight amps.. don't they offer a volume control anyway? they are supposed to be exceedingly good. First Sound is one of the best passive preamps around and is highly recommended