I hadn't seen a lot of three-channel amps. That particular arrangement first showed up in the 90's, when center and surround speakers were just showing up and people wanted to keep their existing stereo amps but also add the three new speakers. These days, with the prevalence of 5.1 and 7.1 systems (and even the option of 9.1 if you are messing with PLIIz and have rear surrounds), piece-mealing it with two- and three-channel amps would be a pain and stacks of two or three Model 2200's would be about as easy and would take up about the same (or less) space. And if you look at pricing on packages of Model 2200's then compare that to the price for a 7500, I bet that two 2200's would be the same price or cheaper than a two-channel version of the 7500. That being said, I do think that the idea of a stereo amp using the 7500/7700 or 7900 amp modules could be pretty cool. I just have my doubts that they are likely to build such a product with the 2200 already on hand, since a monoblock allows for complete flexibility for folks who want a particular number of channels and the 2200 is slim enough and reasonably stackable enough to be practical even when combining a lot of them.