System Health Check - Any recommendations?

Unplug and disconnect everything. Remove all dust with a clean damp cloth. Clean all the connections with a clean cloth and alcohol, and/or your choice of contact cleaner/conditioner. But alcohol and effort works just fine. Main thing, keep doing it until the cloth stays clean and white and the parts look shiny new again. Clean everything. Pull the tubes, clean the pins, clean the sockets. If you don't have a tiny pipe cleaner then just plug and unplug a few times. Clean inside the little RCA holes, inside the power cord plugs, everything.

Reconnect everything. Do your best to have all the cables separated, neat and tidy. Use something to hold speaker cables up off the floor.

Turn everything back on. Let everything warm up while you go out and buy some anti-static spray for clothes. Waft the spray over your system. Sit back and listen. Yeah, I know. Who'd a thunk? Take the money you saved, that you were about to throw away, buy some Better Records.
https://www.better-records.com/search_adv.aspx?option=s_name&min_price=1&max_price=&manu...

There are several key concepts for the proper design, layout, and execution of miniDSP-based audio systems. The first step is to make sure all the elements of your system are set up correctly and efficiently by performing a number of verification measurements.

 

Please see our video - Using Key Measurements to Verify Basic System Setup