Noisy sampling with OPL 3-sa2 card

[Michele Debandi]

Hi all,
I have a K6/166 with Red Hat 5.2 installation and its 2.0.36 kernel 
sound driver. Under windows 95 I can sample from external sources
with an acceptable quality. When I try to record (for instance with
wawrec) something under linus I notice a slight noise. 
Seems to me that the anti alias filter remains wrongly selected.
How can I modify by hand the anti-alias cutoff filter frequency?
I think I can send an ioctl to /dev/dsp.

Mike