TBL1S input module shall be a transformer-isolated, line-level, balanced input module. The module shall have a pluggable 3-pin screw terminal input barrier strip connector to make the input connection. The module shall have a jumper selectable input impedance of 600ohms or 10kohms. The module shall have a gain/trim control that will allow the gain to be adjusted from -11 to +19dB. It shall have the ability to mute lower priority modules and be muted by higher priority modules. The module shall be able to assume any of 4 priority levels. The module shall have a VOX/gating circuit to control muting of lower priority modules and its internal gating circuit with controls for threshold and duration. It shall have a continuously variable ducking control that will enable attenuation of the input signal from a minimum of -10dB to a maximum of -72dB relative to the normal unmuted condition and a gradual fade back from mute when the mute or gate control is deactivated. The module’s output shall be assignable to either or both of two mixing buses.