[hifiguy2008]

Hi Everyone... I'm new but planning to join the Bryston family soon. What is the collective opinion on the SQ differences between the 2.5B3 and the 4B3 amplifiers, in the context of driving a pair of Confidence C1 MkII speakers. It's an fairly averaged size room, about 18x25. Nothing crazy in volume or bass-head-ness.

I value imaging and detail, while maintaining musicality. The same thing we all want, to be transported to the musical event and forget your listening to a (really good) stereo.

Can I save the money with the 2.5B3... it would really help my budget, but at the same time, I don't want to make a mistake. Thoughts appreciated!

[Aschen]

I guess not ironically I think the 3b3 is about the right size for your application.

My speakers are the larger version of yours C4 (though Mk1), I have ran them with my bryston integrated which is basically a 2.5B SST amp with a preamp built in. For being such a "little" amp it can reach quite high SPLs cleanly with those speakers. Still it runs out of juice a bit before the speakers are the limiting factor.

I currently am using a 4b3 which I think is plenty of power even for the big dyns. I would guess 2.5B would be plenty of power for the C1s but since they are such fine speakers I would probably go a bit bigger to the 3B for extra headroom. I think 4B3 is a fine choice as well but I think the C1s would be well over driven before it even approaches it limitations.

There is the more power is more better contingency, but my experience is contrary for the most part.

[rob80b]

Really comes down to ones listening habits and choice of music, I ran a pair of Dynaudio Contour 1.3MKIIs off a 3BST for years in a similar sized room, 15 x 28 to pretty high levels without distortion but was able to bottom the woofers on occasion with non-compressed recordings, so started crossing over with a Velodyne sub which also greatly increased the dynamic range by taking the load off the mains for reproducing the lower base notes.
Currently running my Dynaudio Special 25s off a Bryston 3BSST 2 which actual replaced a 4BSST but in a smaller sized room, 10 x 15  so no real hit that I can gather from dynamic reserves.
In your size room the 2.5 while it may appear to power the C1s and sound just great the 3B or even better the 4B would offer a lot more assurance and fluidity, especially with dynamics and louder listening.