Built this device together with my son. Testing all the buttons, sliders and encoders went fine. Playing music however was hardly possible as it continued to skip and stutter. This happened even when we were just playing a single song, without touching any of the controls.
I’ve assembled many electronic devices before and I’ve checked all the soldering which looked perfect.
I’ve tried to use another power supply (original raspberry pi 4 supply which is known for its stability), but this didn’t solve the issues.
I’ve tried a different high quality SD card, but this also didn’t solve the issue.
Tried it with headphones and… it suddenly worked perfectly fine. So I started to suspect the speakers.
Diconnected one speaker… and all of a sudden the device worked fine. Disconnected the other speaker (reconnected the other) and it continued to worked fine.
Then I decided to measure the resistance of the speakers which should be 4 ohms… BUT the one speaker measures just 3 ohms and the other just 2.8 ohms. Which is 25% off of their stated value
My guess is that the DAC / Amplifier cannot handle the +25% offset of what they are supposed to be.
Again, disconnecting one speaker (I decided to disconnected the 2.8 ohm) fixes all the issues.
Maybe this can be of help to some others.
P.S. Circuitmess… you can, but do not have to send new speakers.