Opinions please on a selection of a Preamp.

I own a ARC LS1 powered by ML 336, pair Martin Logan Prodigy speakers, excellent speaker cables (monster). What should I consider when shopping for a preamp replacement for this system.
Both Atma-Sphere products are outstanding.
I'm using (and love) Atma-sphere equipment! My personal opinion, however, for full sonic enjoyment, use an Atma-sphere amp/preamp combo. Happy Tunes!
I know it only costs $1,200 but the AES AE-3 DJH edition preamp makes wonderful music.

While the AS preamps perform quite well with the AS amps and maybe even Rowland amps, I do not know many people that have used them successfully with other amplifiers.
My brother is using an Atma-Sphere MP-3 preamp with a Rogue 88 amp and the combination sounds very good. He is using a Jenson transformer to convert the balanced signal to single ended.