The RU-ADA8D is an eight channel stereo audio distribution amplifier with input and output gain adjustments and input level metering. The module may be operated in mono to provide up to sixteen distributed mono signals. The inputs and outputs are connected on rear-panel detachable terminal blocks.

Each of the two line level inputs accepts either a balanced or an unbalanced signal. Each input is equipped with a front panel INPUT GAIN trimmer. Input signal levels between -14 dBV unbalanced and +9 dBu balanced may be set to the proper operating level as indicated by a dual-LED VU meter. This assures ample headroom at all normal operating levels. The maximum input level is +25 dBu.

A rear-panel switch selects between stereo and mono operation. In the mono position, input A (left) is used to drive all 16 output channels. When the module is used in a monaural system, only input A must be wired.