Recently took delivery of one of these amps, which I connected to my already working RPi 3B loaded with MoOde. I initially powered it using a 19.3V PSU, one that I've successfully used to power another TAS chip amp previously.
No +5V. The board says 18V at the input terminals. So I tried a 16V PSU, figuring OVP on the little on board converter. Get +5V this time, but not for long.
The only way it runs with the 16V PSU is if I co-power it using the ordinary pi 5V input. In this case, the AMP2 plays correctly. If I remove the additional 5V PSU connected to the pi, it drops out dead within a few seconds.
Do I have a defective AMP2 module?
HiFiBerry says it's supposed to power the pi and then some from the amplifier power input. I know the TAS amps are good for 24V and HiFiBerry only warns against using >18V with 4 ohm speakers... Implying it should work with, oh, 19.3V input and 8 Ohm speakers (which I have) no problemo.
I'm using the screw terminals, versus the quick connect for the PSU connection.
Any help would be appreciated. Thanks!