FS#12111 - AS3543: Turn off output mixer AGC as done in AMSv1

Attached to Project: Rockbox
Opened by Stephan Grossklass (keyb_gr) - Wednesday, 11 May 2011, 16:52 GMT
Last edited by MichaelGiacomelli (saratoga) - Sunday, 24 July 2011, 21:57 GMT
Task Type Patches
Category Drivers
Status Closed
Assigned To No-one
Operating System Sansa AMSv2
Severity Low
Priority Normal
Reported Version Daily build (which?)
Due in Version Undecided
Due Date Undecided
Percent Complete 100%
Votes 0
Private No


While AMSv1 targets are set up to disable output mixer AGC, this is not done on AS3543 equipped ones for some reason. The provided patch corrects that.

Available headroom does not seem to be changed in digital audio playback.

Two versions are provided, one for a standard Rockbox and another that includes the "audiophile patch"  FS#11304  (some overlap in modified registers there).
This task depends upon

Closed by  MichaelGiacomelli (saratoga)
Sunday, 24 July 2011, 21:57 GMT
Reason for closing:  Accepted
Additional comments about closing:  Accepted first patch as r30208. Further discussion for  FS#11304  can continue in its task.
Comment by Martin Sägmüller (dfkt) - Thursday, 19 May 2011, 15:39 GMT
I did some RMAA tests on that patch, against a clean default build - results can be seen here:
Comment by Sei Aoyumi (Aoyumi) - Saturday, 04 June 2011, 21:07 GMT
I tested first patch.
It prevents a change of irregular volume in the music that is very high in mean volume. The patch seems to be surely effective.
Comment by sideral (sideral) - Thursday, 21 July 2011, 20:58 GMT
I've been running with this patch (in my case the second patch) for a few weeks without issues. I think it can be committed safely.