Raspberry PI4: listening to left channel only

Core Machine (Operating system/System info/Roon build number)
PC (Windows 10 / Roon core 1.8 build 756)

Wi-fi network 5 GHz (router Askey RTV1907VW)

DAC SMSL M500 via USB

Description Of Issue

I bought a Raspberry PI4B and installed Ropieee to have a separate endpoint and configured it (wi-fi).
Now ONLY the left channel works.
I did various tests:

  • I turned everything off and on again;
  • I updated Ropieee to the latest stable version (3.075);
  • I installed Ropieee again (flash on SD);
  • I replaced the USB cable;
  • I have installed Roon core on another PC;
  • I bought an ANOTHER PI4 and replaced it;
  • I tried another DAC (Dragonfly black).
    Only the left channel works EVEN if I swap the RCA connectors to the amplifier (it seems impossible to me).
    If I go back to the initial setup, I hear both channels (PC as endpoint).

Did you try plugging your Dragonfly directly into the RPi4 to see what you get?

Did you plug headphones into the Dragonfly or wire it to your amp? Try headphones if you haven’t already. Problem might be your amp, IDK.

Also, you you using a HAT on your RPi4? That could be defective.

Right, I hadn’t thought of that. Both the M500 and the Dragonfly work well with headphones. Why then does my amplifier interrupt the right channel with the PI4 and not with the PC? It’s an analog signal …
I am not using a HAT, but the USB port of the PI4

USB from RPi4 to amp is not analog, it’s digital. How do you connect PC to that same amp? Is it also USB into the same USB port on the amp?

Sure, USB is digital. The analog output signal from the DAC (both M500 and Dragonfly) is the same to the headphones and to the amplifier, but the headphones work, the amplifier does not. Could it be a voltage problem and the amp goes into protection?
In my first post you find the configuration

Sorry, I was thinking you were doing USB from RPi4 to amp, thinking the amp had built in DAC. So, I guess I don’t know about analog out of your DAC to amp.

Grazie mille!

I’ll do other tests, but it’s strange. If I connect the USB of the pc to the DAC, it works fine. The cables are the same. Thanks again

I’m guessing, and it’s just a guess, that PC is providing more power to the DAC than the RPi4, in that case.

1 Like