I had very bad whine in my system despite extraordinary attempts to fix it. The final solution was to use a Zapco Symbilink interconnect system between the head unit and processors. My system consists of Nak HU, AudioControl processing, JL amps, Dynaudio speakers. Interconnects are presently Streetwire and Zapco, but I tried a zillion different brands and designs. I disagree that radiation is a common source of noise. Most "whine" type noise is a ground potential problem.

When you say "shield drain", what exactly are you referring to? I've got a fair amount of experience in car and home audio, but have never heard this term before. My guess is that you are attempting to avoid any ground potential difference between the signal ground at the amp input and the signal ground at the headunit output. If the resistance between the headunit chassis and the ground of the output RCA is near 0, then you effectively are doing the same as attaching the interconnect shield to the headunit chassis.

 

There are a number of interconnects designed for car audio that have a foil jacket benieth the insulation that sheilds the twisted pair wires. At each end of the interconnect, there is a small wire that is attached to this foil - the shield drain. Attach this small wire to the case of your head unit and the amp case.

This generic brand amp wiring kit has 1 interconnect, and it has a sheild drain. Available at Partsexpress.com. Part number: 265-035.

G'luck!

 

Thanks, that's what I figured it was.....just haven't seen the term.