Hello!
I have:
1) Orange Pi PC+ with ARMBIAN 5.38 stable Ubuntu 16.04.5 LTS 3.4.113-sun8i
2) Orange Pi Zero with ARMBIAN 5.60 stable Ubuntu 16.04.5 LTS 3.4.113-sun8i
3) Orange Pi PC with Debian 3.4.39 #1 SMP PREEMPT Wed Sep 16 13:39:07 CEST 2015 armv7l
On both ARMBIANs I have noticed: every start of arecord sets level on "MIC1 boost AMP gain control" audio setting with constant value 5.
I think it uses value of "cap_vol=5" from section [audio0] from script.bin.
On Debian it does not.
In my case I need very very very low value of "MIC1 boost AMP gain control".
Value of "ADC input gain ctrl" is already 0.
Any ideas what is responsible: alsa, driver or something else?
And how to avoid that?
The way to repeat:
1) with amixer see current value of "MIC1 boost AMP gain control" - in my case 5.
2) set any another value: amixer sset "MIC1 boost AMP gain control" 4
3) check new value 4 with amixer
4) start arecord to record anything
5) check value of "MIC1 boost AMP gain control" with amixer: it got 5 again