[PlanetCCRMA] amplitude overload problems

Oded Ben-Tal oded@ccrma.Stanford.EDU
Mon Aug 23 05:59:02 2004

I'm encountering some amplitude overload problems when using pd and have 
no clue how to track them not to mention fix them. I'm not even sure they 
are related and they aren't consistent. Here is what I know:
I'm running RH9. I have an audio quattro sound card connetced to a 
keyboard and speakers (no mixer). I get audio from the keyboard as well as 
midi in-out. 

1) running pd with jack the output levels are sometimes overloading (i.e. 
the test audio signal is a distorted scream; reducing the output levels in 
working patches to %1 gets normal sound. On other occasions the level are 
just fine (I think this depends on the boot process since stoping starting 
jack or pd doesn't change tha outcome, rebooting sometimes does)

2) running pd the sound input from the keyboard is overlaoding. strong 
notes are always clipped; to get softer notes not to clipp I have to 
reduce the amplitude on the keyboard itself to almost zero, even then 
sending a strong midinote to the keyboard results in clipped input. 

I played a bit with rosegarden to check the midi outputs and it worked 
fine. I'm also running the same pd code (sending midi out to keyboard and 
getting the audio in) under windows and it works fine.