I have done some more alsa buffer investigation and with the
alsaPlaybackPeriodCount=4 the no of times the mxcsdma interrupt was
called was as follows

mxcsdma interrupt count for 2 mins 32s music alsaPlaybackPeriodCount=4
count    alsa buffer time
207724    3400
40144    20000
12632    50000
7294    92790
6707    92790
6959    92790
6870    92790
7619    500000
7584    5000000
8365    999999999
7283    999999999

if you think that our objective is to reduce noise caused by interrupts
then this shows that the 92790 setting is 29 times lower than the TT3.0
default buffer setting of 3400.

so I think the best alsa buffer setting for alsaPlaybackPeriodCount=4 is
92790. (this is the smallest buffer time that gives a period size of
1024 and buffer size of 4098
for all resolutions ie 44.1 to 96 Khz)

I tried switching back to alsaPlaybackPeriodCount=2 and was surprised at
just how rough the sound was, this mod is quite a big improvement in
sound quality.

this concludes my search for settings that give the lowest noise/jitter
playback for the Touch. The sound is pretty much transformed into a very
high class analogue like presentation without digital artifacts as
experienced in the Touch factory and TT3.0 default settings.

If you would like to try them just PM me, all in strictest confidence.


------------------------------------------------------------------------
SBGK's Profile: http://forums.slimdevices.com/member.php?userid=52003
View this thread: http://forums.slimdevices.com/showthread.php?t=94499

_______________________________________________
audiophiles mailing list
[email protected]
http://lists.slimdevices.com/mailman/listinfo/audiophiles

Reply via email to