Upgrade advice for processor

No, I did not listen to both amps. My advice was not based on any negative experience with the MCA-50. It was based on my highly positive experience with the A5. I used the A5 for both music and movies for two years. It is an excellent product at what is, by audiophile standards, a very reasonable price. You can click on my virtual system to get an idea of the system context in which I evaluated the A5.

I have also heard the D2 on a number of occasions (combined with the P5, which, although it is more powerful, sounds very similar to the A5). So I can make a reasonable inference about how the D2 and A5 will sound together. I believe that combination will meet or exceed your expectation, as described in the OP, of "high quality 2 channel performance" from a multichannel processor/amp. Good luck.

I contacted technical support at Anthem and kudos to them I had an answer within 30 minutes (very impressive). here is what they say the difference in the two amps is.

“A series” has these extra features over the MCA:

hand selected input transistors heat-shrunk together so positive and negative cycles track each other as temperature changes

4-layer circuit board instead of 2-layer for lower impedance

circuit breaker instead of fuse for convenience and lower impedance

I have the Arcam AVR 600 and only paid about $3500 for it. Outstanding unit in every sense. Amazing sound and simple operation. It is everything they claim and more. I think you will be happy even with 2 channel stereo. It is not on the same level as my Accuphase for 2 channel but not bad at all.