Using DC-10 Studio Plus, I couldn't get captured avi to output to VHS
tape. Then someone here suggested hooking up a tv or monitor with
composite jacks to see if anything was coming out of the card. Hooked
up a tv and lo and behold, I got output. So, I hooked the output of
the DC-10 to the in of the VCR, then the VCR out to the tv to watch.
It seemed to record the avi output fine.

So, I thought maybe the previous VCR might have had some kind of
issues with the capture card. But, when subsequently hooking up only
the VCR to output of the DC-10, with no monitor, again, I get no
output to the VCR.

Does this sound right? Shouldn't it be possible to output to the VCR
alone or is there some reason that there has to be a monitor in the
circuit?

No it does not. There is no such limitt of that board known to me and
I often used the board this way (i.e. only the VCR nothing else).

Repeat the test - can you exclude cabeling issues etc? If it turns out
that this behaviour is really the way you describe it that would be
VERY odd.

Markus