Direct Audio as Malfunction Indicator Direct Audio is common to the operation of both transports, prior to recording. It is an output of every audio record amplifier at pin 4. It is then routed to the meter amplifier on the monitor amplifier circuit card via SW204 in Direct. From there it goes to the VU meter. If the audio is good in direct, this proves that pin 5 (-20VDC) from J101 of the bias oscillator, the monitor amplifier, and 1/3 of the record amplifier circuitry is good.