Musical Designs/Concepts has mods for some B&K. I almost sent my pro 10mc and ex 442, but gave a used Rogue Audio Cronus Magnum II, about the same price as sending the amps to Musical DEsigns, a tryout and kept it. The dealer I bought the Rogue from understandably would not take the B&Ks on trade because of the difficulty finding parts to service them. I understand that one dealer in New York got all the parts from B&K when they shut down, but I could certainly be wrong about that. I’m on the West Coast. I like that I can call rogue Audio and talk to someone.