resistor based pitch bending

[unclejambo]

Right, I've numerous instruments with pitch trimpots. I've already performed a mod on a vl-tone, switching out it's trimpot for a higher value pot. This wasn't an exact science, more a case of plonking the first thing I had handy in there which happened to provide me with some pretty low notes.

Just wondering what approach people generally take. i.e. do you measure the existing pot and work in multiples of that value per octave?

Also, I have a casio csm-1 module. This unit has midi in and a pitch trim at the rear. I'd always imagined that a device with midi would have more complicated clocking than a resistor so am wondering if swapping that pot out will achieve a similar effect as the vl-tone.

If not, and I have to graft a ltc module, what affect will underclocking for pitch have on the way the unit processes midi? Will the unit respond to midi note data quickly enough to be useful.... I should probably stress that while I'm keen on glitching and the aliasing effects of circuit bending, I'm a musician at heart and would still like to be able to play/sequence my instruments with a degree of musicality. I'm not really after an unpredictable drone box.

[unclejambo]

I kinda meant in either instance, resistor or ltc clock bending, how will that affect the midi behaviour.


...also there's nothing wrong with drone boxes, I could use one maybe but thats not what I want this to be

[Dylan]

A general rule of thumb is to measure the resistance of the clocking (pitch) resistor and then replace it with a pot that's slightly higher than the resistor that's there. Take for instance if you had a gadget with a 15KΩ resistor, you'd replace it with a 20KΩ potentiometer. With trim pots I would assume you'd do the same, or you could just replace it with a pot of the same value.