options for 2.1 sound

I have a 2.1 channel system with bookshelf speakers, a pre amplifier and a 2 channel power amplifier and a subwoofer. Currently I have an adcom gtp-600 surround pre amp but I'm not satisfied with it (I'm actually quite confident that it's damaged in some way.) I want to get a new pre amp and am wondering what the best solution is. I know that I can get a normal 2 channel unit and run the speaker cables through the sub but I'm hesitant about this because I don’t want to tarnish the power going to the speakers by sending it through the sub. I could opt for another 5.1 channel unit (outlaw audio 950?) but then I'm paying for capacity that I won't use, and likely getting lower quality 2 channel sound than I would with a stereo pre amp. I also have been told that I might be able to employ a 2 channel pre amp that has multiple outputs (Adcom GFP-565?) and send one to the sub and one to the power amp. I’m thinking this may be the best option. Any advice/ help would be greatly appreciated.

hi bill,you wouldnt affect the power going to the speakers by running them from the sub,the sub will only take a sample of the signal then send the power to the speakers.

if your worried about adding something to the signal path by running the speakers piggy back off the sub & coloring the signal in some way then i see your point but it wont affect wattage/power in any way.

you are correct about being able to use a 2 channel pre with multiple outputs in such a fashion,are your buying preferences new or used & what budget.
Check out the B&K PT-3. It is a 2.1 remote controlled preamp, inexpensive on the used market and sounds very good! Has full range, high pass, and subwoofer outputs. Much better sounding than the Adcom.