ERRATA/NOTE: Playmaster Pro Series Four Preamp (Dec 96 and Jan 97): Some kits may have been inadvertently supplied with CMOS versions of the 556 dual timer chip (IC13), which is used to drive the volume pot motor. As the CMOS type has a much lower output current capability than the normal bipolar 556 and cannot drive the motor, you should check that you have the correct version before it's installed. The chip type can be tested by using a multimeter to measure the resistance between one of the control voltage inputs (pin 3 or 11) and ground (pin 7). The CMOS versions will cause a reading of around 200k while the bipolar type will measure about 10k.