The AA103A module provides a 400 or 1000Hz reference tone for alignment and test purposes within an audio system. The AA103A reference tones are factory calibrated. Frequency and amplitude is programmable via berg style connectors directly on the PCB. Three line level voltage source (LoZ) outputs are available, 0, +4 and +8 dBu. One -60 dBm, 150 Ohm output is provided for calibration of microphone input circuits.

The AA103A can be installed in any position in a Serialboxx MF100 frame. Each module comes complete with a TB101 termination assembly that mounts on the rear of the MF100 frame directly behind the slot where the AA101A is installed. All output connections are made via 3-pin Phoenix pluggable screw terminals on the TB101 assembly.