It will not matter what the processor's sampling rate is if you use the analog inputs from the Pioneer's 6-channel output. The processor will not convert any digital signal in this scenario. You really only need a pre-amp not a processor/pre-amp. McCormack makes a 6-channel pre that might be perfect for your set-up.
Pioneer 47Ai / Audio Refinement Pre2 DSP help
I just had Stan Warren modify my Pioneer 47 Ai universal player and I also purchased an Audio Refinement Pre2 DSP preamp processor. As I was reading through the Pioneer manual there is mention of the AV receiver needing to be compatible with high sampling rates (96 kHZ). I checked the manual for the Audio refinement pre and there is no mention either way if it is compatible or not. I am REALLY hoping it is and that I did not make a mistake buying this pre. I bought it specifically because it has the 6 analog inputs for DVD audio and SACDs - I really appreciate any answers you can help me with.