Hmpfh, well, as I have been trying to point out some times already,
timemachine is a program for capturing what you might have thought you
could use, while programs such as ardour, jackrec or jack_capture are
programs for capturing what are sure you want to use. timemachine is
great, but it doesn't seem to me like anyone understand its purpose(!)...
(timemachine captures x time of sound before pressing record, a great
idea, but its for a little bit different purpose than this).
So, to my point, which (of course) was mostly to promote my own program:
Use jack_capture, http://www.notam02.no/arkiv/src . It does exactly what
you want, and as simple as possible.