The RU-ASX4DR is a four channel stereo audio selector with input gain adjustments and output level metering. The module is equipped with an internal stereo VCA for setting the output level. Source selection and level adjustment are by remote control. Each module may be remote controlled from a single or multiple locations. Rear-panel terminals provide flexible control options using a variety of RDL remote controls or OEM equipment. The inputs and output are connected on rear-panel detachable terminal blocks.

Each of the four stereo line level inputs accepts either a balanced or an unbalanced signal. Each input is equipped with a rear panel screwdriver-adjustable input gain trimmer. Input signal levels between -15 dBV and +8 dBu may be set to the proper operating level as indicated by a stereo dual-LED VU meter. This assures ample headroom at all normal operating levels. The module is equipped with two identical dual-led VU meters, one on the front panel, the other on the rear panel. The maximum input level is +25 dBu.

The RU-ASX4DR was designed for absolute silent switching of audio signals using only solid-state switching circuitry. Each of the VU-meters, left and right, is calibrated to read +4 dBu feeding the corresponding balanced output.

Inputs are selected by a sequential remote control such as an RDL D-RCS4, by a momentary remote control such as an RDL D-RC4M or by an external open-collector momentary closure to ground. The RU-ASX4DR may be remote controlled from a single or from multiple locations. When a source is selected, the RU-ASX4DR provides a 25 mA open-collector output to control other equipment or modules. A front-panel LED indicates the selected source. Only one source may be selected at a time. If the momentary input terminal for a selected source is triggered again, all inputs are turned off.

The RU-ASX4DR offers exceptional headroom, very low distortion, excellent crosstalk isolation, wide flat frequency response and extremely low noise with very high common-mode signal rejection. It provides exceptional audio performance for the most critical applications in a professional audio environment.