what I need is exaclty what I wrote: the ability to
record from the
different audio channels separetely. e.g. one /dev/dsp device for each
input.
I have a vague memory of having been able to do this with
the O$$ drivers, although there are so many disadvantages
to using them.
With ALSA, you may want to google info about the .asoundrc,
whose arcane syntax and semantics seem to promise a level
of control which would likely encompass what you are trying
to do.
Tobiah