I recently installed a 3.5mm stereo to RCA plug to stream audio from my PC to my Onkyo TX-SR600 receiver. The connection is direct. No couplers/extenders/adapters/wi-fi/etc. The stream works and I can hear audio through my PC. However, there is a distinct background humming noise through the Infiniti Alpha speakers that are connected to the receiver.
Some research I did suggested it might be a ground loop. However, I tested this by hooking up all electrical components on the PC AND receiver to the same electrical outlet. It did not make a difference. The background humming noise was still present.
I also tried playing the signal through various ports on the receiver, including CD, DVD, Tape, and Video2. All produced the exact same background humming noise.
I thought it could possibly be a defective 3.5mm stereo to RCA cable. So I bought another cable and the sound was still present. So I don't think it is a defective cable.
Thanks in advance for your help.