alsa-project/alsa-lib issue #9 was opened from logan001:
I don't have the card anymore but maybe someone else have it and can provide some help cause i like the card bass/treble control and if the bug is fixed i will buy it. The card does not output side channels at all. 5.1 works but 7.1 side channels gives no sound with speaker-test -c 8 pulseaudio also gives no sound for side channels in speaker tests. i don't know if its the right place to report this bug but i've tried on kernel bugzilla and there is no movement there. the kernels i've tried 1 month ago are 4.18 and 5.1.15 here is the [alsainfo](https://bugzilla.kernel.org/attachment.cgi?id=283467) at that time
what i found strange is that alsamixer when i change the sound card had the side channels volume set at 0. its like by default was build intentionally without side channels support.
and yes i have that special cable with 3 jacks (sound card) to 4 jack (for speakers). i have it from an old audigy 2 zs if i remeber corectly. and the cable works since i tested 7.1 in windows without any issues.
Issue URL : https://github.com/alsa-project/alsa-lib/issues/9 Repository URL: https://github.com/alsa-project/alsa-lib