I am looking into getting a used cp-251 to play with alongside my LP.
I am curious what it might take to add a toggle switch to the cp-251 to flip it from its normal .2-50hz to something more like 2-500hz.
Are there schematics available?
No and no.
You could use CV and push it higher, but I’ve never measured how much. It isn’t too high into audio rate. You can easily double it by rectifing it and getting 2 positive going signals on each oscillation instead of one positive and one negative.