Hi there,

I've been trying to sort it for three or four evenings.

I designed a patch which does basic audio mixing and routing between pd and external apps.
Some features in this big patch are brought to my eyes when clicking on toggles, simply opening pd patches using "Pd open ..." messages. This way I can call different "instruments", in a mutually exclusive fashion.

Sometimes, in a apparently random way, this action of closing the last window opened and opening a new one leads me to an audio distorsion (and hums of various types) on the "main" two outputs of the "big" patch, while audio sent by "child" patches to two other DAC remain clean. For days my only response was to immediately close Pd and other services and restart everything. Sometimes the sound went back clean, but sometimes the second "run" remained "dirty". Afterthat I realized that I could either continue playing with my windows opening/closing till it (apparently randomly) gets clean again !

Of course when window open an short overall glitch can be heard, but I can stand that. I imagine this is "normal". The previously mentionned distorted sound occurs on a very simple ADC1 DAC1 bypass sothat I can hear the incoming instrument signal and I "play" with my window opening/closing till the audio starts to distort.

I use jackdmp on a core2-duo pc with UbuntuStudio64 8.04.3, reasonably efficient. I use a 2-4 M-audio fasttrack pro with alsa and Pd-Extended 0.41.0 .

I am a noob, but I wonder if this could deal with some kind of "discussion" between Jackd and Pd when opening and closing patches ?

Every idea about who to fix this or what's happening would be welcome.

Thanx,

Nau

i think it dependes what you are loading. large patches seem to freeze pd during loading. i realized this distortions whenever i loaded a new sample in an array. it helped to start each patch in a seperate instance of pd

I'm real new to Ubuntu - three weeks - for the past couple of days I've been having some distortion problems between pd ubuntu and jack - I just went into the start up manager and saw that the default operating system had changed from the real time kernel (2.6.31-11-rt) back to the generic kernel. I changed it back - restarted the computer - problem solved, Get the start up manager from the ubuntu software center in applications - or do all this in the terminal. Also - try disabling networking before you start jack. Hope that helps.

Thanks Simon2, but these hints are useless to me - already checked

thanx, loading using different instances of Pd did the trick ... but raises my idle %cpu (seen in Qjackctl) from 10 to 15%. I'll go ahead this way anyway.

Nau

In my case it's possible to start two different instances of Pd at the same time, but not three. (Jacks complains saying a client already exists as soon as se second instance is launched).

Is there a way to start three or more instances, and is there a way to change the name of these instances (the two working are called PureData-0 and PureData-1 if I remember well) ?

Thanx