Hi
I recently purchace an Lg Oled Tv and hookup my Volumio Rapsberry Pi to my new tv set. I did’t make any other change in my setup, the analog output of my USB DAC on the PI is still connected to the same stereo power amp and so on… Now I heard a buzzying noise at medium volume. If I disconnect the hdmi output from the Tv set the noise is gone. Clear and buzz free. Tried other HDMI cables… not bad but still that background hummm noise. Any advice on how can I stop this? Thanks.
Seems you have a earth/ground loop.
Please describe the full setup, like brand, every connection that’s connected to the rPi, TV and amplifier.
Is your TV also connected to the Amp?
Any home made cables?
Hi.
TV → LG Oled C1 55inch
Volumio → RaspberryPI 4
Micro HDMI RapsberryPI 4 to HDMI input of the TV set
USB Dac used for Volumio → Audioquest DragonFly 1.5 black
Analog output of Audioquest DAC → 3.5mm to stereo RCA stock cable (not home made)
TV is not connected to the Amp… well not physically connected.
Toslink from the TV set hook to the Pre-Amp, but as this is not “physically” connected to the tv (optical isolation), should not matter here.
My power amp is a pair of Rotel pre-amp (can’t remember which model) and a Rotel power amp.
Rotel pre-amp already have a special power outlet where only the two hot wires are presents, I guess to help to prevent ground loops.
Tried to find on Amazon any kind of male-female RCA connectors that would incorporate a ground lift but didn’t find any… Guess I’ll have to go to my favorite electronic shop, bought some RCA jacks and craft myself some cables leaving the ground not connected to see if that will fix the issue.
I still need to test what will happened if the tv set AC Power is coming from another power outlet than the power bar where all my setup is connected. Do you think that can make any difference ?
I saw some usb isolators on Amazon, in particular the one made by Audioquest, the JitterBug FMJ, wonder If this could help to isolate from ground loops.
Thanks.
Can’t see any strange thing here.
The optical connection (TV-Amp) can indeed not cause any loops.
Please try to connect the TV to the same power outlet and see if it make a difference.
I know from personal practice that TV’s introduce a lot of rubbish side effect.
I had some audio dropouts with my LG OLED.
After I googled this I found out the LG’s are varying a lot with their DPLL bandwidth. This makes a less combination with the Sabre DAC’s.
Do you have a Sabre DAC and are you able to adjust the bandwidth?
Best regards,
Jordo