I’ll ask Gordon at iqAudio about this. It seems strange the board would need the additional parameter just to work out of the box. If this is the case, it’s certainly something that can be improved
The IQAudio power amps are muted by default in hardware. Until Raspbian 4.4.14 it was necessary to unmute the power-amp with a shell command. Since Raspbian 4.4.14 it is possible to use the device-tree statement. Have a look at section 12 of the IQAudio User Guide.
I am actually working with Gordon on producing images that work with the DAC out of the box.
I thought ALSA had to be used to unmute the mixer. I was exploring a kernel patch to address this. Being able to do this via device tree is handy. Thanks for bringing this to my attention.
I know that this is an old (one year) thread, but with the january update (2018) I suddenly have no sound from my IQaudio DigiAMP+. Everything looks correct, but suddenly I have no sound what so ever.
Any others with similar issue, and more importantly anybody with suggestions to how I can debug this.
If nothing else I will try another fresh image on it and see if there is sound then (or even worse it is hardware failure…)