[alsa-devel] M-Audio FTU issues

Felix Homann linuxaudio at showlabor.de
Fri Jun 24 11:08:39 CEST 2011

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Hi again,

Am 24.06.2011 03:14, schrieb Daniel Mack:
> Hence my question is: How do you guys test? I renderened a sine tone
> in different samplerates and bit depths to .wav files and play them
> with aplay (no pulseaudio or anything in the chain). Could you try the
> same and report what happens?

OK, I've rendered a sine to a .wav (well, in audacity), played it via 
aplay on the FTU8R and could hear the clicks. I've been using plughw 
though, cause I don't remember right now how to convert bit-depths.

I even played sines directly from puredata and audacity without JACK and 
could still hear the clicks.

Please, make sure you have the routing "diagonal", i.e. "DIn i - Out j" 
is set to 0% if i !=j and 100% if i == j. I've attached a small bash 
script to accomplish this. After plugging the device in all playback 
volumes are initially at 100%. I could not notice the clicks then unless 
it turned the volume very very loud (I guess aplay plays back on all 
channels, which blurs the clicks).

If you still can't hear the clicks please try using a headphone? 
Sometimes the clicks are hardly noticable when there's minimal 
background noise. You might even have turn the volume higher than 
convenient for your ears...

I hope this helps hearing the clicks using the unmodified driver.

Kind regards,


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