Buying a used amp for $2500 with out auditioning

Go for it. Read as much as you can about each candidate, narrow your choice to one and find a good deal. The worst that can happen is you won't like it, so put it back for sale, maybe you will lose a few hundred bucks but you gain a home audition and a wealth of knowedge. I purchased one amp brand new for 2400.00 without ever hearing it and it is my favorite, a keeper for the rest of my life. I purchased another one used here on Agon which I'd never heard before and am happy with it although it's probably not a keeper for life.

My entire 2-channel system was assembled by purchasing new or used equipment on Audiogon I never auditioned or saw in person.

Far more useful than the "professional" reviews I've read in magazines were the discussion posts at this very site. I felt confident because I didn't base my decision just on written single account reviews, but a series of Q&As and comparisons with similar gear and enviroment to mine. I'm pretty confident that even if the piece isn't a perfect fit, I know I'll at least be in the ballpark.

Nothing better than a few hundred fellow audiophiles to help you out.

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.