This is long get ready!
Dump the bryston and denon... Sorry, without the right speakers they both are gonna be thin and not that balanced, I owned both... Those brands work well with polk speakers using like Soft dome tweeters.. Paradigms are not the right speaker for this. I use a 3805 which never worked perfectly with metal speakers, or ribbons to well. Surround sound it is great! Not the best on music. Although Nuguy makes a point with the EQ, your talking a whole Converting Balanced to RCA connection and back in your system, or using the Behringer as the DAC cause it has one built in, but at that point you already have a 8 band EQ built into each channel on the 3805 already, I can't remember how many bands but it has it.
My 3805 runs music DVD's with Sub and movies with sub just fine, but I have that in a Hometheater seperate of my 2 channel. You CAN use it as a 2 channel preamp with some success, but your gonna need a quite different amp at least in my opinion. Like an Ayre(pretty pricey), An old Forte' like the 4a.. Maybe a Classe', or an Odyssey Strato's, MCINTOSH would totally help... Stay away from Sunfire or anything like that.
I have heard Rotel or B&K could at a cheaper price work, but you gotta test that out these should be easy to find local new for a test drive.
Anything thrown inline with Tubes could really help.
But if you must, your easiest attempt will be get a pair of fairly pricey but still cheaper option Cardas Golden cross interconnects for your amp to preamp. See if you could audtion something local and return and see what happens. I have heard Cardas cables like this help tame some problems in your regard.
Only other option is to attempt a 150.00 DAC-AH from Pacificvalve.co it is KILLER analog sounding and cheap, far better than the dac's in the Denon and way better bass with smooth vocal and midrange. It would fatten up the sound a little I believe, but without a real preamp oppossed to the surround sound receiver it may not give you the best synergy.
By the way I listen to much Chains' and Tool, Just saw Tool live and might see the new AIC at a show, guess what the CD's Unless you are listening to the new 10,000 Days disc will leave a bit to be desired in the recording, they are a bit thin, but the new Tool disc is one of the best recordings ever done on a heavy album, very thick sound and never fatiguing. I don't mess with the discs too much on this cause the Vinyl is superior, I own them all for both bands and on a 25,000 vinyl rig its superior to digital no doubt! Good luck...
Or go headphones, a lot of the thinner discs sound good that way, but not to good for a party obviously, this would be the cheapest fix in your case :).