What Power Amplifier Should I Buy?

Instead of a bigger Bryston get another 2.5B and vertically biamp. I did this to good effect when I had Revel 228 Be. Don’t run them mono, but use each channel of one amp to power the highs and lows of one speaker, or horizontally one amp the highs and one the lows. That said, while the sound may be cleaner and you have a bit more headroom, the difference may not be that huge. You are probably only using a small amount of watts from your existing amp. I found it beneficial overall though, and I don’t listen that loud either.  Only issue is using a y-splitter for your preamp outputs if you don’t have one with two sets of outputs.

By the way, the advice on looking at preamps may be good also if yours is truly a ‘softer’ sounding unit. I preferred the Bryston amps with a Bryston preamp, it provided a certain jump factor that was very much missing with other preamps I tried, including Primaluna, SPL, and DAC direct. I used a BP17. The only thing I didn’t like about it was that it was noisy. Also, I eventually settled on a NAD M23 amplifier. 1st class D amp I would recommend over something like a Bryston, and I’ve owned the different technologies over the years, Pascal, Ice, Hypex, etc. The NAD gives up just a little bit of bass slam to the Bryston (not much though) but is otherwise more refined and has a nicer midrange, and provides lots of clean power (200/400w in 8/4 ohms).  It’s cheaper also, and IME was not a sideways move.  Definite improvement for my tastes.  

Agree with YYZ I would not use the 2.5s in mono, but as I recommended in my post if you use them to vertically biamp your speakers (since they are biwirable) there are many advantages to that over a larger stereo amp.  

The BP17 is great with the 2.5, best match I had with those amps. There is a brand synergy there for sure. I haven’t heard the BP19 or BR20. The Benchmark LA4 is one of the best preamps I’ve ever had, especially as far as neutrality goes. It is a gem and at its price a tremendous deal. But for synergy with Bryston amps I’d probably get a Bryston preamp, if it were me. Plus as you mentioned you get the dual outputs.

Lastly, another option if you want to stick with Bryston and/or save some $$ and shelf space, the B135 integrated has preamp outs.  So you could use that with your 2.5B to horizontally biamp.  

@kevemaher thats why I recommend not using them as monoblocks, which is what Bryston is talking about. In this case they are bridged and each amp becomes one channel and doubles the power into 8 ohms. Try to find specs though on what they put into 4 ohms when bridged. It’s not recommended for speakers like Revels.
If you use one channel though from each amp to power the highs and lows of a speaker you let the amplifier ‘see’ a much easier load than if it was powering the whole speaker, and offering much more headroom. Active speakers (like ATC) have an amplifier for each driver in the speaker. You’re right, and as I mentioned in my first post you need a preamp with two sets of outputs or you can get a y-splitter for your preamp. Incidentally, when I had two 2.5s I tried them in this configuration as well as bridged monoblocks, powering the Revel 228 Be. It sounded ok as monos but not as good as the other way. A bit muddy. And two amps definitely sounded better than one, but the difference was not huge.

I don’t think you could go wrong with a 3B or a 4B, but I was looking at it from a price perspective. Probably cheaper to pick up a used 2.5. But also, from a power perspective, 2 smaller amps may be better than one larger. The 2.5 is conservatively spec’d. It’s basically a 150/300 w amp into 8/4 ohms. So biamping, at 4 ohms you’re getting 300 w/ch into the mid and tweeter, and 300 into the woofers, and each amp channel sees an easier impedance load. With something like a 4B you would get 500 w/ch into each speaker and it will see the combined load of the whole F208.