Plenty of people have already chimed in on this topic, but FWIW here's
one more vote.
I think it makes a lot of sense to have a large knob for coarse tuning
of a frequency shifter. No, it doesn't necessarily need to be the size
of the Bode or AS freq. shifter knob, but it does make sense for it to
be larger. From a Human Factors perspective, you want the most
important function(s) on a module to be easy to locate and change,
under a variety of circumstances (for example, a live show with little
or no direct lighting). Even more so on a complex system with a lot of
modules, since there are a great many controls, and therefore it's
potentially harder to find the most important ones.
Making something "easy to locate and change" can take many forms, but
IMHO making the knob larger is ideal, since you accomplish two ends:
you make the control easier to see and get to, and you make it easier
to perform subtle adjustments.
Personally, I think that Technosaurus have absolutely the right idea
here (to clarify/emphasize, I'm speaking of knob sizes). If you look at
their VCF2 module, you see that there's one oversized knob for the
filter cutoff. Likewise on their oscillators, where the octave knob
(16', 8', etc.) is larger than the other controls. And the filter
cutoff knobs on their triple res module are larger and located in such
a way as to be very easy and quick to find.
Jurgen Haible's fascinating JH-5 synth is another excellent example of
this principle. He uses a combination of layout and knob size to create
visual separation between important functions, and to emphasize the key
controls. (
http://www.oldcrows.net/~jhaible/jh5/jh5.html).
My point is, the MOTM format has a lot going for it, but I think it
would be a mistake to let the designs created up to this point dictate
how layout and knob sizing will be handled for all future modules.
Mike