ASM-1 vco range

[jimh54]

Anyone know how to decrease the range of the VCO's on an 
ASM-1? Mine has an extremely wide range. Haven't measured 
the frequency range but the knob only turns about 1/3  
before the frequency is above hearing range. I want to lower 
the range on the pot so it only operates in the audio range.
same is true on both VCO's. I used MAT-02 matched pairs and 
all precision 1% resistors.
Thanks,
Jim