Finally took the Bryston 4B Cubed plunge

jafant,
Now I await your update on the 4B3. =)I speak for myself and hopefully elizabeth as well when I say, "try it, you'll like it."

@jafant for interconnects I'm using either Audience Au24 SX (admittedly a little out of whack price-wise with the Brystons) or DH Labs Revelation. I also have DH Labs Air Matrix and some assorted other budget things lying around, but most of my time has been with one the Audience or Revelation.

For speaker cables, Audience Au24 SX or DH Labs Q-10 Signature. Power cable has been Audience powerChord SE-i, DH Labs Corona or the stock 14-3 cord which is actually pretty ok on the 4B3. 

The funny thing is early on when the Brystons weren't broken in, I much preferred the DH Labs wires - the Audience made the darkness and murkiness worse. Then as the gear opened up, the DH Labs became a bit too forward and I went back to the Audience, and now everything is lovely. The Audience are more refined cables and cost a pretty penny more so this isn't an indictment of the excellent DH Labs cables at all, but I also think it points to how it takes time for the Bryston to balance out. If gear works well with the Audience that could be taken as a good sign we're getting closer to the big leagues, as they are outstanding wires used as a reference in some extremely impressive ($$$) high-end systems. 

@elizabeth I haven't used the BP26 but I have experience with the preamp section of the older Bryston B60, which is pretty much the same as the BP6 which in turn uses the same fundamental discrete op amp circuits as the BP25 and BP26 and shares the same sonic signature. (Bryston says this themselves and isn't shy about showing this in the schematics.)

Based on this experience the Bryston preamp circuit is very musical and nice, but fundamentally colored by the electrolytic caps. There simply isn't any electrolytic that's truly neutral. The old Black Gates were the best sounding I had heard and the recent Mundorfs are very nice (I'm using them in my B60), but they're not anything like film caps, much less straight wire. The funny thing is these caps are often warm and fuzzy sounding once broken in, generally softening the highs and adding fullness (some would say bloat) to the lower midrange and bass. This actually works out great in the Bryston as it balances out any potential hardness/brightness in the op amp circuit, and it also adds warmth that helps make their amps sound better (synergy!). I think if you swapped out the 'lytics for a better film cap that's very fast and clear, the preamp would actually sound worse. Ultimately holistic balance in the circuit/system is more important than absolute correctness of a given part, and this is why it's worked for so many years. It might sound like damning with faint praise but hey, it's your enjoyment that counts!