Circuit-Bending a Large Keyboard mat. Clock Resistor issues

[iclevine]

Hi!
I am new to the forum but have been circuitbending for a few years -
I am currently working on a project with a friend where we are attempting to add a pitch knob to a giant walkable keyboard like the one from the movie Big. (This one : https://skymall.com/products/sa94723-big-giant-piano-mat). By licking my fingers I have found the clock resistor and when I touch it I can make the pitch warble, but when I tried to measure the resistance between the two points on the circuitboard the keyboard turns off immediately. This was also the case when I try to attach a potentiometer to the two points.
My questions would be as follows :
-Have you run into this issue before? (and if so whats goin on?)
-What is your process for determining the value of  a potentiometer you attach to a clock resistor ?

Thanks so much !
iclevine

[Circuitbenders]

You should be able to tell the value of the clock resistor by the markings one it. You won't be able to measure it accurately in circuit.

You're probably wiring in a pot with a far too low resistance so it tries to run too fast and crashes. If you're wiring it in parallel with the resistor then you're only ever going to get a lower resistance than the resistor thats already in there.
Take out the resistor and wire in a pot of a bigger value, then turn the thing on and turn up the pitch until it crashes. Disconnect the pot and measure its resistance, then wire a resistor of a slightly bigger value in series with it. Wire the pot back in and the resistor should act a a limiter.