Onkyo vintage with speaker hum (1 Viewer)

[Scott Cohen]

I have an onkyo vintage av reciever. Has a two prong plug which is plugged directly into wall outlet.
I get hum from my mains when I switch to THX or any kind of surround sound. No hum when using just mains for music. My input source is toslink from smart tv.

Any suggestions?

Thanks!

 

[Gary Seven]

What else is hooked up to the receiver... anything? Are you using the tuner from the TV or is there a cable box?

 

[Scott Cohen]

I have a chromecast audio for spotify hooked to the second toslink input. No hum when I play music

Tuner is in tv, no cable box

So the only inputs are the two toslinks. Video goes to the tv via ethernet.sound for home theater runs through the toslink.

 

[Gary Seven]

Typically, a hum is a grounding issue. Sorry, I am not too familiar with the configuration you specified but I would disconnect everything, reconnect just your TV to the receiver and see if it still hums (leave off the Ethernet connection). If so, there is something there in your hook up. If not, then hook up the next thing and see if it hums, and continue till you find the culprit. The idea is to try to isolate it.

Maybe someone else has a configuration similar to yours that can chime in.