@rustyd02359
Sorry, I didn't make the proper connections in my brain last night.
As I mentioned, there are quite a few dedicated "preamp/processors" out there. However, new, most are going to run you north of $3000. They are going to have all or more feature sets, including Dirac, that the Yamaha has.
So, I guess the big question is, what is driving your question. Assuming that you are using the A4A as the pre/pro with the pre-amp outputs to external amps, or not? Are you looking to improve the sound quality by switching to a dedicated pre/pro? Do you have a budget in mind? What amp(s) are you using, and speakers?
-Jeff