The R in that equation is the input impedance of what you are plugging the TS lead into, as I understand it. What do you think the output and input impedances are if you are running out the KPAs TS output into a mixer or amplifier?
600 -> 10k maybe? It's too low for capacitance to be of concern. A passive guitar -> amp would be around 5k -> 1M.
R = source impedance in your calculation. You have to put brackets on it, btw 1/(2pi x Zout x Capacitance)