You looking to maintain the home theater multichannel or shifting to just 2 channel stereo? What are you trying to achive or make better?
Quickly, if staying in the home theater market, yes, there are many. Just Google "a/v processor" or "home theater processor" and you will get many choices, although they tend to be much higher in price than the A4A. Brands like Anthem, Emotiva, Marantz, Rotel are among the bigger names. You also have options to use the preamp outputs and add off-board amplification.
If looking at 2 channel preamp, then the question is what features and what you are trying to accomplish need defining first.
- Jeff