Rus, you are correct. The only advantage with biamping with two of the same amp is having an additional seperate power supply. I really would not hear a difference and the A21plus has advantages the A23plus doesn’t. I’m thinking of using a tube hybrid, the Vincent SP332 for the mids and treble and the A23plus for the bass. Otherwise, I’m going with the A21 plus. Any thoughts on this would be appreciated. Thanks.