Although I don't have experience with the 7BSST, I once owned the Betas and used a 4B NRB for the bass columns. It was OK, but I eventually replaced it with a QSC M3000a. I believe it produces enough current for 900W/ch into the Beta's 4 ohm impedance. The QSC had much better tone definition and slam than the Bryston, and is available at professional musician's outlets for around $1000. QSC has since gone to digital switching power supplies which might be even better. The main thing with the Betas is to use tubes for the mid/twt columns.
Your Experience with Bryston 7BSST.....
I need to replace my B&W MPA 810 MonoBlockcks, used to drive the Woofer Sections of my INFINITY BETA. Unfortunately, one has gone South, and B&W aren't disposed to repair them, and in spite of schematics, I'm having no luck getting them repaired. SO...this brings me to the BRYSTON 7BSST. I understand they are outstanding in Current Delivery and other "Bottom End" aspects that might make them a good choice for this application. I've seen the BRYSTONS (various models) used extensively in Pro-Sound/Touring P.A. systems, and know their reputation for reliability. I've had no exposure to them in "Home Audio" situations, and that's what this query is about: Could any of you Out There on AudiogoN share your First-Hand Knowledge of the BRYSTON 7BSST, particularly regarding the Low End ??? Thanks !!!!!!