[ardour-users] ardour and usb 1.1

[Frank Barknecht]

Hallo,
Šumpich Petr hat gesagt: // Šumpich Petr wrote:

> I'm using ardour on SuSE Linux 9.1 (2.6kernel) UMAX410T notebook
> (1200Celeron, 256MB RAM) with Roland Edirol UA-20 usb external
> soundcard. 
> 
> Notebook has only USB 1.1 and there are problems with too much data
> going through the usb port (i'm hearing loops, even ardour click has
> some jitter, latency problems, rhytm is not regular, problems.
> 
> I think the problem is that there is really too much of data:
> capturing in 16bit 44100Hz, playbacking through the same soundcard.

It's not a problem of too much data, USB can handle this and even
more.

> Also have some SiS integrated card - SiS SI7018 on board, i have
> decided to be this card to playback, i hope it will do better.
> 
> 1.	Will my problems disapear when putting Edirol only to capture,
> SiS only to playback?

You will get other, even worse problems. Bottom line: You cannot use
two soundcards at once with one Jack server.

To solve your USB problem: *Always* run USB devices with Jack at
sampling rates which are multiples of 1000. So not use 44100 but use
e.g. 48000 Hz. (Some people report success with 44100, too, but this
is very fresh.)

This probably will solve your problem, but another thing to do is to
work with bigger period sizes (and thus latency). Try 256, 512 and
1024. Als try if "-n 2" or "-n 3" for Jack makes a difference.

Ciao
-- 
 Frank Barknecht                               _ ______footils.org__