Discussion about the Korg PolySix synthesizer

Clearly there is a problem with some other part of the MG circuit if
you have increased R52 from 150 to 12K and the max frequency is still
1/6 of what it should be.  I would look at Q3/VR5, R55, 68, 69, TH1
as these control the current into IC21 which seems to be the problem.
I would put R52 back to 150 ohms and look for the real problem.

    Bob