Architect's Specification

The unit shall be a 6 channel, 3 output zone mixer in a 1U rack mount 
chassis. Any input shall be routable to any
output or combination of outputs using internal jumpers and front-
panel pan controls. The input configuration
shall consist of three mono mic/line/aux inputs and three stereo line 
or mono mic/aux input channels. The outputs
shall be configurable as stereo + mono or as three independant mono 
output zones. All mic inputs and zone
outputs shall be on balanced XLR connectors. Line inputs shall be on 
balanced 1/4" jack connectors. Phantom
power, gain trim, pad and lo-cut filter facilities shall be avilable 
on the mic inputs. Input channels shall have peak
condition LEDs. Aux inputs and channel direct outputs shall be 
provided on 15-pin D-connectors in order to
allow linking of units to increase available inputs or outputs.

Inputs shall have a prioritisation facility with selectable depth of 
ducking and output zones shall have
compressor/limiter facilities provided. Alarm interface circuitry 
shall be provided such that an alarm condition
immediately routes the alarm to all three outputs, removing all other 
inputs and indicating an alarm condition via a
front-panel LED.

The 3 output zones shall feature front-panel level control, metering 
and headphone monitoring facilities. 

All input and output channels shall be level-controlled from either 
the front panel or from DC voltage remote
controls. The unit shall have an integral power supply but shall also 
provide for battery backup operation. A
signal flow diagram shall be silk-screened on the chassis to assist 
installation.

The unit shall be the GR1 zone mixer from Allen & Heath