Originally Posted by badsha
I have exactly same problem! Same Hifi harnes from Technic and xd600/6 hissing noice Even at minimum gain and at muted.
Even i can hear scartching noise sometime in te rear soeakers... Im out of idea...
"Scratching" noise is caused by loose connection somewhere in the amp (inputs/outputs). Hiss is the noise floor of the amp just amplified over an acceptable level.
Some batch of PDX amps used to produce hiss at minimum gain/no audio. My personal solution for that was to replace that particular PDX amp. Problem solved.
Bad connection at the harness RCA will produce a different kind of noise, "scratching", pops, low volume level or simply no sound at that particular RCA/speaker output.