What active preamp...

...it's actually more on colouration and bringing the sound away from reality rather than being simply bright that is not neccesarily.
with short interconnect runs and sencitive poweramps you can get away with cheap passive pre-amplification that will be compatible with expencive active preamps.

Marakanetz, I have found that using Argent Room Lens clones between my speakers has eliminated the problem that is normally caused by having the equipment between the speakers. This is very easy and cheap to try. Instructions for them are on the Jon Risch DIY room treatments website. I made 6 of them for about $50. I then followed the Argent recommendations for placement, and found out that they worked very well.

The reason I am mentioning this, is because maybe you can get back to passive this way. And also, look at the Bent Audio website for the new wave in passive controls.

TWI is correct about the room lens I removed mine for few minutes to see the difference it was significant build them yourself they work.

There is at least one active preamp available which actually runs in passive mode up to unity gain, then switches in the active section above that point on the volume control. I don't rerember the name(s) but I read about it here somewhere. I suggest you try searching the archives or use the search engine for "passive".

Bob, it's adcom gfp750 that is great in passive mode and also has a unity gain, but first i'm not sure how far it brings music from real in active mode... The length of wires adds too much resistance for a 600mV...1V signal.
despite having a sencitive power amplifiers I still need a positive gain. I can also try to buffer thorugh Musical Fidelity tube buffer that might reduce the wire impedance influence...?
I'm also tended to consider Room Lenses and if it will bring me the stage that I have now I will forget about going active ever.