Yes, I have a 5803 hooked up with a Theta Dreadnaught amplifier. I use the Theta for the front three channels and the Denon for the rears. Eventually, I plane to add two more 200 watt modules to the Theta and bi-amp the front right and left channels. It is also very important to use a separate dedicated circuit for a separate amp which makes a huge difference. This system sounds tremendous and I find they match well. The best would be Theta's own processor but they are a great deal more money and this way I have enough power for all the speakers I wish to use and a good processor and interface in the Denon. I obtained a 5803 for a very reasonable price making my choice that much easier, and I can still go to separates using the Theta at a later time.
