Personally I think you got some bad information. While Classe is a very good match for the 800 series B&W's, the truth of the matter is that B&W themselves use Levinson amps at their factory. I know this from reading an article about B&W where the author mentions the Levinson amps used when he toured the factory, plus I have a DVD about B&w and in the DVD you can clearly see that they use Levinson amps in at least one of the sound rooms at the main B&W facility. I have heard the 433 amp, not driving B&W's though, and it is an outstanding amplifier. The only issue I would have right now with any Levinson product is the apparent difficulties that currently exist with their service department. The local dealer who used to carry Levinson, that is where I heard the 433, who now has dropped the line, mainly because of this situation, related some horror stories to me about the service at Harmon. The good news is that the 433 is very well built and there shouldn't be any service issues,hopefully, for many years.
