i'm using a HT-oriented pre/pro (rotel rsx-1055) - it's actually a reciever, but for 2ch i'm using the main outs to separate amplification - and i can tell you from having tried several 2ch outboard preamps (in place of the rotel) that there is A LOT of room for improvement there. i've used tube based pieces such as the Eastern Electric, and an old-school PAS-3 (non-X) and found they changed the character of the entire system drastically. i've also used other HT pre-amp only (outboard processors) and found things were different.
note, i said different. not always better. simply put, you're going to need some AMAZING (read: $$$) interconnects in order to overcome the separation of the two pieces. put another way: moving the processor out of the same box of the pre might solve a few things like power supply, noise, whatever, but has the potential to cause a LOT of headache / nightmares / costs.
for HT, i'd say either get a better integrated pre/proc. and amp, rather than spend money on separeate processors and preamps (the only reason i'd suggest that is for upgradability re: different formats in the future). for 2ch / music, i'd say, separate them to your heart's content: lets put it this way, you can spend the $$ on 2 really nice ICs vs 8 for 7.1 :)
note, i said different. not always better. simply put, you're going to need some AMAZING (read: $$$) interconnects in order to overcome the separation of the two pieces. put another way: moving the processor out of the same box of the pre might solve a few things like power supply, noise, whatever, but has the potential to cause a LOT of headache / nightmares / costs.
for HT, i'd say either get a better integrated pre/proc. and amp, rather than spend money on separeate processors and preamps (the only reason i'd suggest that is for upgradability re: different formats in the future). for 2ch / music, i'd say, separate them to your heart's content: lets put it this way, you can spend the $$ on 2 really nice ICs vs 8 for 7.1 :)