[mythtv-users] Hum on analog audio to TV

James Crow james at ultratans.com
Wed Oct 22 12:48:54 UTC 2008


On Tue, 2008-10-21 at 16:17 -0400, James Crow wrote:
> I have two Myth systems currently running. Both are connected by analog
> audio to RCA inputs on the TVs. My master BE/FE works great. 720P and
> analog stereo. My secondary FE (no BE on this box) is having an audio
> issue. It is connected to the TV at 480P component with analog sound.
> Whenever the Myth box is turned on there is an audible buzz from the TV
> speakers. I have tried switching from the built audio to an external USB
> audio device and the symptoms persist. Does anyone have any
> recommendation of things I can try to fix this?
> 
> Thanks,
> James
> 
> 
Several great ideas so far. Let me fill in a few details. 

1) TV does not have digital audio input and this is in the bedroom, so
no receiver, etc. TV has built in DVD player and has S/PDIF _out_ , but
not in.

2) The is a slave FE. No BE, no tuners, no coax connection. Master BE/FE
does not have some problem so it is not on the recordings.

3) TV and Myth box connected to same outlet. I rewired most of the house
to add ground connections and I know this outlet is properly grounded.

4) Coax is grounded to same grounding stake as house power at point of
entrance to house.

5) Coax is connected to TV only.

6) I think TV has only two prong power plug not grounded plug.

Things I will try tonight.

1) Flip TV power plug over to swap hot neutral.

2) Disconnect coax from TV. Maybe it still has ground from there.

3) Connect wire from PC chassis to coax outer braid.

4) Build isolation transformer.

Thanks for all the ideas I will let everyone know what fixes it.

Thanks,
James




More information about the mythtv-users mailing list