309F-1 - Digital to Analog converter
    Used in conjunction and aligned with the 915V-2.  Takes digital information and converts it to analog, tune sequence, fault interlock.  Consist of 3 sections:
        - Digital to Analog power supply
        - Digital to Analog converter
        - Tune sequence control circuits
    The Tune sequence control circuits control the operation of the PA Frequency Word storage
599Z-1 - Test set
    Contains address recognition strapping for the PA.  If the address is correct, the information is sent to the 915X-1 and the jacks on the front of the slice.  The jacks are interrupt jacks and will break connection with the audio patch panel.  Also available are 20 analog function test points and 3 voltage check points.  Analog function test points directly access analog voltages from the PA

652J-13 - Power Supply
    Similar to the 652J-14, supplies all continuous and switched voltages, but for the PA Cold Compartment ONLY, to the other 5 slices
915V-2 - Amplifier Control
    PA Plate current Servo controls:
        - 4 servo pre-amps
        - 4 voltage shaping circuits
        - IGC
        - 2 filament regulators
        - PA plate and screen current monitors
        - FWD and REF power monitors

915X-1 - Control Monitor
    Control and monitoring of the (V)2  PA
    DCU/DCFE, only one contained in the entire PA.  800KHz oscillator for driving clock to multimeter, contains relays for multimeter range selection, extra card, A5, for extra relays needed for extra multimeter functions