Adcom GFP-750 pre with Bryston 4BST amp works?

I cant answer that directly, but I hust hooked up an Audio Research LS-3 with my 4b and its a great combo. Better than the BP20/25 that I had. Great deal for 600-700$

Passive balanced it should be fine. There are mods you can do to make it even better active.

I had this combo for one year and it sounds great. I prefer the preamp in active mode though. Just upgraded to 4BSST and it is even better. Have to spend a lot more to get better.

Interesting I had the Adcom and preffered the pre in active too.Bummer was I had the whole stack (GCD and 5802) and it was just too much juice for my little 805 Matrix B&W's.Sounds like a good combo to me but I might want to try a Bryston 20 or 25.Ultimately if you have the speakers for it the active Bryston X-over.It would be a and all Bryston sound and be a bit more but might be better.But the Adcom is a hell of a good pre-amp if you have not problems with switching electronics.Adcom's could be built a bit better.