Buying a used amp for $2500 with out auditioning

For $2500 used you can get a lot more amp than just a Bryston 4B-ST. Try a Plinius, Sim Audio, Pass Labs, Gamut, Blue Circle, etc. If you do purchase an amp and find out you don't like it in your system then you just turn around and sell it.

Now from personal experience, I own a 4B-ST, I have auditioned the 7B-ST in my system for a week, and I just purchased a Sim Audio Moon W-5. IMS the moon abolutely smokes the 7B-ST monoblocks in every way; dynamics, control, imaging, soundstage, transparency, top-end air, harmonics, etc. Note, that I am not saying anything bad about either of the Bryston's, just that the moon is better.

There are some great deals on the Pass X-250 power amps for a little more used here on the gon. I would try to add some to the amount and fo with a better amp like the Pass, Levinson, McCormack and the others already listed above before getting into a mid-fi amp.

Sim Audio Moon W-5 or the Blue Circle BC-26.

Yeah there's going to be no easy answer for you without actually auditioning an amp and "biting the bullet"! The best way is to buy an amp and try it. Like the guy's say..."if you don't like it, sell it and buy another!" No big deal really. If you don't have the time, you'll not likely end up with great sound anyway. You need to experiment to get the best results often...otherwise, don't expect to get it right in one try...that's a rare trick indeed.
good luck

If you decide on the Conrad Johnson I would make sure that it is the "A" version. It is more detailed than the non "A" version. The Pass X250 is also a good choice but it will be a bit more expensive than your $2500 dollar limit.

Chuck