Thank you both.

The mono/stereo switch on my box doesn't seem to do anything, although I may not be utilising it properly... I don't know as my Behringer box doesn't seem to have any kind of user manual other than a very basic quick-start guide.

In any case, it's not the end of the world. Either I can record to a mono track, or use both inputs if I'm not recording anything else at the same time, or record to one-sided stereo and then just mix it after recording.

Cheers for the help!