Bryston or Classe

Bryston has a punchier house sound. Classe's is more delicate. You seem to like hearing the details, which would suggest the Classe. However, a Bryston preamp might provide some synergistic benefits paired with your 4Bst. Also, you may lose much of a Classe preamp's delicacy after passing through the 4Bst. Recommend borrowing both and trying through your system.

For 2ch listening just upgrade the receiver to the Bryston SP-1. It is great for 2ch listening and functions as a home theater processor. It is upgradable and has their same 20 year warranty. I don't agree with placing the Bryston in the same class as Acurus. I own an Acurus amp also, and the Bryston blows it away.

I would go with Bryston, partly for the synergy with the 4Bst (which I've owned and I feel is a phenomenal amp for the price, much less colored than any Krell I've ever owned or heard, and in a completely different league than the Acurus and Aragon amps (which I've also owned). I think the BP-25 is nearly unbeatable, and if you ever do decide to resell it, it will retain a lot better value than the Classe stuff. The 20-year warranty speaks for itself.

I have a friend that has Classe and has had nothing but trouble with Classe. He has sent his integrated back 5 yes five times in the last two years. He has had no problems with any of his other components. They claimed to have rebuilt it each time. His name is being withheld since he wants to dump the amp and buy Bryston.

I owned a Bryston BP-25 mated with my 4B-ST amp and there was synergy with this match up. However I did swap out the BP-25 for a tube preamp (Rogue 66) and in doing so gave up some of the detail but realized the warmth I was looking for. As a SS preamp the BP-25 is hard to beat and ya gotta love that they hold their value and offer the best warranty in the biz!