My 4B-ST runs Hot

Argent,
I'm not familiar with the speakers that you have, but, if they aren't very sensitive or dip into the low ohm range (1-3 ohm) they can make your amp run pretty hot. Especially if you like to listen to your music quite loud. I used to have a pair of Infinity Kappa 8's and they would dip into the 1 ohm range (with sensitivity at about 84-86db)and would make my amp run VERY hot, could even cause the amp to activate it's protection circuitry if we really cranked it up. And this amp had plenty of arse. I now have a pair of Legacy Focus that are sensitive speakers (95-96db and operate @ 4 OHM) and don't have this problem. My amp rarley even gets warm. That Bryston has tons of arse, so either your speakers are the cause, as mine were, or the problem is elsewhere. Maybe someone else has another suggestion. Don't know if this helps. Good luck.

Joysjane,
I have the Legacy Convergence, which were rated by Legacy as having the same sensitivity as the Focus. Audio magazine reviewed the Convergence and measured their sensitivity at 92db. Legacy seems to include room gain in their figures. I still love em !! (the speakers). My OCM 500 amplifier runs around 115 degrees with these speakers. At 130 degrees things become to hot to hold your hand on.

You mentioned that the amp seemed hotter on the right side of the top. The 4B-ST is a symmetrical construction, with the heat sink modules each containing a separate channel of amplification, with the twin toroid amps occupying the center of the chassis. The only other factor I can think of that might cause excessive heat on one side (given the symmetrical internal layout) is a badly adjusted DC offset. I think your problem merits a call to Bryston, since excessive heat will decrease the life of the solid state parts and output transistors.

My 4B-ST runs warm on the top and warmer on the sides as there is little space between the heat sinks and the sides of the cabinet. Never too hot to touch but the sides do get verrrry warm...

Argent, have you tried swapping the amps input cables left for right to see whether their are any sources issues? Ie now the left side is hotter than the right. Similiar experiment would be to swap left for right speaker leads (with source correctly connected) to isolate whether there are any "load" issues. This info will probably be useful if you talk with Bryston.