Airplay doesn't work with asynchronous DAC!

Volumio Development Bug reports
1

Sorry I cross-posted this, but I realized this may be a bug.

When I try to stream from my laptop to Volumio with Airplay (through Airfoil) to my Meridian Explorer asynchronous USB DAC, the artist sounds like a martian! The sound is heavily distorted; a kind of nasal, scrambled sound with a high pitch. Otherwise, playing through the Volumio interface to the Meridian from my NAS works like a charm. Airplay works fine with my IQAudio i2s DAC.

Laptop: HP G72
OS: Windows 7
Volumio 1.41
Airfoil 3.6.1
USB DAC Meridian Explorer

2

It seems all the shairplay devs are using the cheap 16bit usb dacs. Since airplay is 16bit this works perfectly when using “hw” as these dacs use s16_le. But async dacs tend to either support s24_le or s32_le only so you ned to edit the script in /etc/init.d/shairplay and replace hw with plughw. mpd has built in format conversion, but shairplay does not. Plughw let’s alsa take care of the format conversion.

3

Thanks, Soli! Do I just replace the word: ‘hw’ for ‘plughw’ in the file: ‘shairplay’? (I am a Linux rookie)

UPDATE: I only have a file ‘shairport’ in init.d. It does not contain the word: ‘hw’.

4

No, shairport is launched in player_wrk.php

So you have to edit this file, looking for the shairport launch script (with nano use shift+w to search) … Let me know if you need more info!

5

Where can I find that file?

6

/var/www/command
:wink:

7

Im actually not using Volumio, but the symptoms described i can remember from my own experience making my own server (but with normal Debian). Maybe michelangelo can update this for newer releases if my theory is right.