KSTR
Major Contributor
@tmtomh,
Use a balanced cable from the EQ to the power amp which has XLR's as I may assume, this is an unbalanced RCA to balanced XLR adapter cable which must look like this:
RCA Center goes to inner conductor (+) of the balanced cable,
RCA Shell goes to inner conductor (-) of the balanced cable as well as the shield of the balanced cable.
By this, the offending mains balancing current is diverted away from the signal path wires, causing way less -- if not totally removed -- hum/buzz.
Combine this with moving the EQ Unit (probably a class-II -- 2-prong -- mains device) right on top of the Oppo (which is Class-I) and connect them with the shortest RCA cables you can find, preferably ones with a thick and solid shield construction.
That should suffice to fix that little issue. If not, please report back for further assistance which then might require more details to be checked. Do you have a good multimeter than can display true RMS AC voltages and measure resistances, and some soldering skills?
Use a balanced cable from the EQ to the power amp which has XLR's as I may assume, this is an unbalanced RCA to balanced XLR adapter cable which must look like this:
RCA Center goes to inner conductor (+) of the balanced cable,
RCA Shell goes to inner conductor (-) of the balanced cable as well as the shield of the balanced cable.
By this, the offending mains balancing current is diverted away from the signal path wires, causing way less -- if not totally removed -- hum/buzz.
Combine this with moving the EQ Unit (probably a class-II -- 2-prong -- mains device) right on top of the Oppo (which is Class-I) and connect them with the shortest RCA cables you can find, preferably ones with a thick and solid shield construction.
That should suffice to fix that little issue. If not, please report back for further assistance which then might require more details to be checked. Do you have a good multimeter than can display true RMS AC voltages and measure resistances, and some soldering skills?