I have one https://www.adafruit.com/product/2130 connected to https://coolcomponents.co.uk/products/surface-transducer-large
The amp is powered from a 5V power supply.
When Bela is not connected in the circuit there's no noise (basically only GND and Vin of the amp are connected to power supply).
When I add Bela, noise is introduced in the circuit. The full connections are the following:
AMP Vin > 5V (Ps)
AMP GND > GND (Ps)
AMP A+ > Bela out 7 (it doesn't make any difference which out I use)
AMP A- > Bela GND
Note that at this stage Bela is not even powered up and still, I can feel noise coming out the actuators.
If I power Bela with another 5V power supply (through 5V barrel) the noise increases even more (and clearly audible, especially from the audio output).
Am I doing anything wrong? Any suggestion to what I could try?