I am building a Raspberry Pi speaker. I’m using gan old Raspberry Pi Model B (revision 2.0) which is already running Shareport Sync.
I’d like to hook up my Raspberry Pi to the Adafruit Stereo 20W Class D Audio Amplifier - MAX9744, but also have them utilising the same power supply. From what I’ve read online this is possible, but I am unsure how exactly to do this. I have some thoughts, and am hoping someone can tell me if I’m wrong - here are the steps I think are needed:
Connect MAX9744 Amp to power supply 12V DC 5A (e.g. https://core-electronics.com.au/12v-5a-switching-power-supply-45158.html)
Wire the VDD and GND pins on the MAX9744 Amp to a step down regulator:
The step down regulator will in turn be wired to a micro USB plug (https://core-electronics.com.au/usb-diy-connector-shell-type-micro-b-plug.html) which will then power the Raspberry Pi (with protections still in place)
Will this set up work?
Which step down regulator is best? The voltage regulator sounds less efficient, and I read it may cause heat. It only has 1.5A as well. Is this enough for the Pi? The buck convertor seems to be more efficient, but has only 1A - so same question for whether this will power the Pi?
I am planning to use the MAX9744 Amp in analog mode. But want to check that if I set the Amp at some max volume level using the the potentiometer, I will still be able to control the volume at the source (i.e. from the Pi running over AirPlay)?