Bryston 4BSST or 6BST or 7BST

The SST series amps have a more refined top end, and therefore are in more demand. I'd go for the 4B SST based on that alone, notwithstanding it's better sonics.

As an owner of Bryston 4B-ST and 5B-ST amps, and someone who has also done fairly extensive listening to the newer SST models, I have concluded that the SST models have somewhat different sonic characteristics than the ST models, but I'm not sure I'd go so far as to say they are "better". Some owners of Bryston amps, as well as several audio reviewers, have said that they prefer some characteristics of the ST line to the SST line, but it would take very good speakers and a discriminating ear to hear much difference between the ST and SST models.

The 6B-ST is a 3-channel amp that has the same power rating in each channel as the 4B-ST (it actually uses 3 of the same amplifier modules as found in the 4B-ST).

Unless you really need a LOT of power, in which case the 7B-ST monoblocks are a great choice (and an excellent buy at $2900), I'd probably opt for the 4B-SST and save some money for later upgrades. The 4B-SST is an excellent amp, and is rated very conservatively at 300 wpc (actual bench tests reveal that it could be rated at about 350 wpc).

If you need the power, then the 7BST is the way to go. I had it before I moved on to the Pass X-600. It was an excellent musical (as well as powerful) amp for my B&W Matrix 802s even if it lacked the ultimate in tonal refinement that the Pass provides in spades. I believe the Bryston products, because of their incredibly generous warranty of 20 years and workmanship, do keep their resale value well. I found that to be the case when I sold mine.

(I listen to mostly classical music, if that is relevant information for you.)

Best regards.

From what I have heard between the 4BST and 7BST, the 7BST was better sounding in terms of dynamic and drove the speakers with ease. More open and relax sound than the 4BST in the Joseph Audio RM-22 and RM-50 speakers. If I'm going with Bryston again then I would definitely consider 7BST over 4BST