AP500 and its application circuit (c)

It is a power amplifier circuit that uses field effect tubes for push-pull output. Due to the use of field effect tubes for output,
the circuit output tone is quite like a tube amplifier. The debugging method of the circuit is the same as in Figure (b). It is worth noting that pins 2 and 3 and pins 13 and 14 of the AP500 are
specially designed for external adjustment potentiometers . It can be left empty and not connected to any circuit, but it is strictly prohibited to short-circuit it.