Originally Posted by giuseppecaporus
i have a precision and a mm pickups with piezo conductor (passive magnetic and piezo ) shoul i use a 250 o 500 k ??
Piezo and magnetic pickups should not be combined without buffering. The impedance of the magnetic pickups will basically short out the piezo elements. You need either a dual input preamp, or two buffers.
It's a personal preference on pot values.