As a follow-up to those that participated in this thread - Not only did I elevate the speaker cables and ICs as previously mentioned, I just elevated the power cords on the mono amps and put pipe insulation around the power cords for the APC and Processor since they are still on the floor. THEN, boy had I overlooked this, there is approximately 12 feet of excess SPDIF digital cable that runs under the floor from the iMac to the processor. That excess cable was coiled up under the computer desk and laying all over the surge protector. By installing three small cup hooks on the back of the computer desk I was able to wind the cable (very loose) around the hooks twice and up to the computer. Now it is off the floor, not coiled, and intersects power cords that hang down the back of the desk at sharp right angles. Now, for the first time ever in my tweaking endeavors have I noticed a distinct improvement in the sound - The music is much clearer than before. Oh, I should mention also, I eliminated the very short Toslink cable that ran from the back of the iMac to a Toslink/SPDIF converter and replaced it with a USB cable that goes to the same converter (also a USB/SPDIF converter). Maybe that was the big difference but whatever, elevating those cables, separating ICs and Speaker cables from cords, and the switch to USB has combined to make a big difference that I wouldn't have believed had I not heard it for myself.
Thanks for all of your input!
Thanks for all of your input!