[mythtv-users] audio issue - HDMI tv

[Tim Draper]

 ---- On Mon, 26 Mar 2018 12:15:25 +0100 Alasdair Macdonald <wewalkforonereason at gmail.com> wrote ---- 
 > I'm a bit confused by your description of what device is connected to 
 > what other devices, and how, but it sounds to me like a CEC issue. 
 >  
i thought that might be the case. currently i'm setup as follows:
rpi3 > HDMI > TV
rpi3 > usb audio > lepy external amp via 3.5mm.
also tried rpi3 > lepy amp via 3.5mm but same problem.



 > CEC is the HDMI feature that allows control messages to be sent along 
 > with the HDMI data, eg to switch on a linked device: 
 >  
 > https://www.howtogeek.com/207186/how-to-enable-hdmi-cec-on-your-tv-and-why-you-should/ 
 >  
 > If I understand correctly, when it is powered, your TV is trying to 
 > enforce use of the HDMI cable / device to which it is connected. 
 >  
 tried both HDMI CEC on and off.  thing is, i can have the TV connected to the mains with tv remain turned off (remote control off, or physical rocker switch on the tv) and have the rpi3 unpowered and the noise is still present if the lepy amp is on. ONLY happens when i have 3.5mm and HDMI TV cable  connected. theres something between the rpi and tv.
I've tried CEC on, and CEC off on both the tv and rpi3 /boot/config.txt file - no change.