Strange hum on new Yamaha AVR

[admin_exported]

Hi Guys

Just replaced my ageing Yamaha AV receiver with a shiny new Yamaha RX-V667. Seem to have a problem though. Always used the front channel preouts through my Cyrus amp with the amp in Cyrus's secret AV mode (acts as a straight power amp). However when I have set up the new AVR in this way there is a constant low level (but annoying hum) from the speakers. It's the same on all input channels and is independent of the volume setting on the AVR. Have been through the long and confusing manual but I can't see any possible explanation for this. Anyone come across anything like this before?

Thanks

 

[audioaffair]

You say the hum is the same on all inputs - can you confirm if this hum is only coming from front speakers as connected to the Cyrus or from the other speakers too?

 

[Anonymous]

Definitely just coming from the front pair of speakers connected to the Cyrus. It goes if I mute the volume on the AVR but as soon as there is any volume at all it appears and is at the same level whatever the volume on the AVR.

Thanks

 

[audioaffair]

If you still have the original AV receiver and it wasn't doing it with that, it'd be worth swapping back to check it isn't a fault that has developed with the Cyrus or it could possibly be the cable you are connecting the AVR to the Cyrus with picking up hum if it isn't shielded. Let us know how you get on and we could fault find further..

 

[Anonymous]

Thanks

Have tried swapping it back and no hum. However old AVR was connected via optical leads whereas new is via HDMI. The noise seems to be coming from the sources (Sky HD box and Sony Bluray). When they are off there's no noise from the AVR but as soon as they're turned on the hum starts. Is low level noise characteristic of HDMI audio signals? I'm using reasonable quality leads....

 

[chudleighpaul]

Could be an earthing problem. Try connecting an earth lead between your sources and the Yammy. Just loosen a screw and wrap a piece of wire round it, and take it to the Amp. Some amps actually have a terminal for an earth strap.