Allen&Heath DR128 SERVICE MANUAL - Manual (Page 61)

54 Appendix
DR128 U SER G UIDE
Architect’s Specification
The unit shall be a digital mix processor with 12 analogue inputs and 8 analogue outputs.
The unit shall have a full crosspoint matrix, comprising 96 points, allowing any input, or
combination of inputs, to be routed to any output or combination of outputs. All
crosspoints shall have a variable level. The 8 mic/line inputs and 8 line level outputs
shall be on balanced XLRs with level trims. The 4 stereo line inputs shall sum to mono
and be on RCA phono connectors with level trims. Comprehensive ducking capability
shall be provided.
The mic/line inputs shall have internal jumpers for pad and phantom power selection.
The mic/line gain range shall be 18dB to 60dB with input impedance of 2k

(no pad) or
10k

(pad). The phono input gain sensitivity shall be internally adjustable from -10dBv
to +4dBu with an impedance of 10k

. The inputs shall be converted using a 24 bit
analogue-to-digital converter.
The XLR outputs shall have a variable senitivity from -10dBV to +4dBu with an output
impedance of 50

. The conversion shall be by a 20 bit digital-to-analogue converter.
The unit shall be configured over a standard RS232 port using a proprietary 32-bit
Windows™ based software application with a Graphical User Interface. Configurations
shall be editable both on and off-line. The configuration shall determine the allocation of
internal signal processing resources to input and output channels, as well as routing,
passwords, levels and channel names. After configuration, the unit shall run standalone,
without an external computer. Signal processing resources available shall include
compressors, gates, limiters, graphic equalisers, parametric equalisers and crossovers.
Optional expander cards shall provide the facility for additional signal processing
resources and/or supplementary delay resources. The unit shall use Flash memory to
permit firmware upgrades via the RS232 port. An internal real-time clock shall allow
scheduling of timed events.
The unit shall be compatible with BS5839 installation requirements. The hybrid
switched/linear power supply shall allow emergency operation with a single 24V external
battery and the unit shall interface with alarm systems. The total power consumption
shall be no more than 70VA and the permissible incoming mains voltage range shall be
configurable to 100, 120, 220 or 230 VAC.
The front panel shall feature 12 installer-definable function keys for user control of
volume levels and patches. A removable fascia shall enable custom labeling. There shall
also be a backlit LCD for indication of setup menus, peak conditions, patch status and
channel levels. Important system parameters, such as Patch Naming, Channel Naming,
Limiter control, Ducking control, Phase reversal, Routing assignments, Date/Time, LCD
contrast and Soft Key definitions shall be password-protected from user adjustment.
Facilities for remote switching of unit parameters shall be provided.
The unit shall weigh no more than 10kg in a 2U rack-mount chassis. The chassis shall be
constructed from zintec steel and feature a removable top for configuration of internal
jumpers and presets.
The unit shall be the Allen & Heath DR128 digital mix processor.