In answer to Jdillard.
Yes most class D switching amps do use the B&O with the expeption of Spectron, which use their own proprietary module plus a lot of very high speed sampling/feedback plus a very large transformer. I have listened to the B&O based units and the Spectron (Musician III) and the difference is very significant. And I agree with Jw94055 that a tube preamp is definitely advised.
Yes most class D switching amps do use the B&O with the expeption of Spectron, which use their own proprietary module plus a lot of very high speed sampling/feedback plus a very large transformer. I have listened to the B&O based units and the Spectron (Musician III) and the difference is very significant. And I agree with Jw94055 that a tube preamp is definitely advised.