Help installing Phat Dac



Using Pi Zero with DietPi distro.

From thread: PHAT DAC Which GPIO are in use
Connected to Phat Dac with:
Pin 1 (3.3V)
Pin 2 (5V)
Pin 12 (GPIO 18)
Pin 35 (GPIO 19)
Pin 39 (Ground)
Pin 40 (GPIO 21)

Did: "curl -sS | bash"
Error on not finding speaker-test.

Installed “alsa-utils”

Ran curl again. No sound on test.

Did all the manual steps.

On “aplay -l” says “aplay: device_list:268: no soundcards found…”

Apps cannot find sound output.

Don’t know what to do…


Are those wires soldered to the pHAT DAC or merely passed through the holes? If the later you’re never going to get reliable contacts that way.

The other thing I would advise is to try with a SD flashed with Raspbian Jessie first as DietPi seems a bit anemic out of the box…


I have pins soldered to phat dac, then jumper wires are added onto the pins. This is so just to test. Will do direct solder to another new Zero Pi after everything works out on my test one. Pic:

I need it to be diet pi as distro, it has features I must have for the project.

Let me know how we can diagnose.


I can only advise again that you try with Raspbian first. If it does work then you’ll know you can discard an issue on the hardware side and go back to getting it to work with your preferred distro.


For what it’s worth, I installed DietPi to check it out for myself and the problem is that /boot/config.txt is not a resource you can edit directly.

Instead, you need to edit /DietPi/config.txt and add the device tree overlay there.

Incidentally, I find it obnoxious that a distro can build so heavily on Raspbian to the point of masquerading as the parent distro. If it did not you would have saved yourself a bit of time when our installer had refused to do its job since your environment was not supported.

… either way, it’s definitely possible to get the pHAT DAC working on DietPi, but you shouldn’t expect the phatdac installer to set you up, it was not designed for this I’m afraid.


Installed a full raspbian jessie, card worked well. Hardware is sound, connection-wise. I used speaker-test to play different frequencies to different channels.

Thus, would I get an assistance here to have it play with dietpi?


as far as I can you need to manually edit /DietPi/config.txt and add


… and probably comment out:


basically, you need to follow the manual install steps described at:
and verify that all the changes you make have not been wiped at the next reboot, due to the RAMdisk based system.


Ok, got it to work. In dietpi there is no ‘dtparam=audio=on’ but there is ‘dtparam=audio=off’ that I did comment out and all is good.

Thus, thank you!

PS: A side question. I have a I2C display, will I be able to use GPIO2/GPIO3, that is pins #3 and #5, while running phat dac? Just curious if there would be any conflict.


yes, that will be fine.


One more question. I’d like to send phat dac output to a mono amplifier. What would be the best way to join stereo to mono?

Would putting two rectifier diodes in V shape from positive outputs do it?

I this project
…a person is using resistors instead of rectifiers.

What would you suggest?


did you ad dtoverlay=i2s-mmap

Good With SuperCollider Andrea_Schiller
Just make sure to add:


to config.txt



I am sorry, what would this do? That is, if I add this, what this would accomplish? Without that entry my music software works just fine.

However, I do have a mono amplifier that takes a single channel input. I need to wire 2 channels from phat dac together without damaging phat dac. Please re-read my question above.