Would XLRs resolve my hum issue? (Marantz and Emotiva)

[mywhitenoise]

I currently have a Pioneer VSX-52 connected to an Emotiva XPA-5 amp. After introducing the amp into my setup, I gained a hum that's been driving me crazy ever since. I've tried to find the ground causing it, but no luck. Would adding a pre-processor with XLR inputs solve the issue (specifically a Marantz AV-7701 OR 7005), or is there a cheaper and better alternative?

I'm not sure who I'd have to call to have this sorted out. Thanks for any advice.