MOTM

'Evening all... having satisfied myself that my MOTM-120 is indeed in proper
working order (a good gain boost does help a lot, as well as judicious
selection of signals), I've started going over the MOTM-410 construction.
My question relates to R68, the resistor which is put in place when the
modular is to be used with MOTM-300 oscilators.  At some point in the
not-too-distant future, I'd like to use MOTM oscillators.  At the same time,
I don't want to leave out the option of using the filter on other signal
sources.  For the moment, I won't be soldering in the resistor.  

Is the resistor simply to be used on 10V peak-to-peak signals?  And if so,
will the planned pre-amp module bring signals up to that strength, requiring
the resistor at all times?  Or is there something else about the MOTM
oscillator (I can't imagine what exactly, amperage?) that makes it
necessary?

Thanks!!

--PBr