Hello Pimoroni community,
I am very excited to become part of this great community. I have been an avid reader but never actively interacted or contributed yet.
For my debut I am trying to build a Bluetooth Speaker with Pi Zero W and Phat DAC.
I have a male header on the Pi Zero and a female header on the Phat DAC.
I have also soldered cables on the Phat DAC for the audio output. I then try to use a VMA408 class-D AMP (https://www.velleman.eu/products/view/?id=435574) which should be similar to the Adafruit MAX98306 (https://www.adafruit.com/product/987). The AMP then powers one 8Ohm/3W speaker.
So actually I am looking for a mono sound source but have just ignored that for now. Not sure if this might cause my issues.
I get the Rpi 0 to be discoverable by bluetooth and open to connect to. When I connect my phone to it I can play audio via Spotify, etc.
The problem I am encountering now is, that I hear quite some noise, hissing, etc. possibly CPU sound and I am clueless how to get rid of it. I was suspecting a ground loop but I am not really sure about that as I only have one power source, the USB cable (I have an Adafruit powerboost to make it portable but leave that out for simplicity for now).
Can anyone point me toward the right direction to get rid of the noise? Did I make a mistake with the wiring? Is there interference issues? Do I have a ground loop and if so how can I get rid of it.
Alternatively I was also thinking of a software fix, possibly cutting of any connection to the amp/speaker until an actual signal is coming from my phone.
I have attached a few pictures of my setup and are happy to share my code if that helps.
Let me know if you have questions and thanks for any reply.