[linux-audio-dev] Re: the big jack bug... > crappy audio on XRUNS

[federico]

Luis Garrido ha scritto:

>Hi!
>
>I had a similar problem in my laptop when using a USB soundcard
>(Edirol UA-25). For me it was not necessarily associated with xruns.
>  
>
ops i checked, i said XRUN, i meant graph timeout of qjackctl

>Since ardour doesn't record the noise, I would say that the problem is
>not in jack, but in the alsa driver.
>  
>
me think too

>It sounded also more like a distortion than noise, since when the
>output levels were low the effect was less noticeable.
>
>I found empirically that harddisk writing operations like saving a
>file in an application would sometimes make the distortion stop, I'll
>be damned if I know why (interrupts?).
>
>Anyway, setting my USB unit to work at 48 kHz made this problem
>practically disappear.
>
>  
>
i will try...

>HTH,
>
>Luis
>
>  
>
>>it happens randomly, while I play a soft synth, that jack XRUNs once,
>>and the audio become crappy, noisy, like a kinda of digital
>>effect....bit crusher?
>>
>>then all synthesizers (all audio apps) sound the same sh*t...
>>i tried recording with ardour the output, and the output is clean, so I
>>guess is a problem of sync or something that has to do with the hardware
>>(soundcard).
>>
>>in order to record this noise, i had to connect the soundcard output in
>>its input and record it via analog in:
>>http://xaero.ath.cx/jackbug_stereo.wav.bz2 (it is a stereo file, with
>>the clean track panned on the left, and the dirty one on the right).
>>
>>i hope it could be useful to debug the problem...
>>what other information I can provide useful for debug?
>>note that this happens with many version of alsa (1.0.9b, 1.0.10rc2,
>>1.0.7 or less) and with many kernels (gentoo-sources (slightly patched
>>for speed improvement), ck-sources, ck-sources+realtime-lsm)
>>
>>i hope to solve this problem, since my audio desktop is unusable as si,
>>since audio crasher after playng for just 5 minutes :(
>>
>>
>>    
>>
>
>  
>