Allen&Heath DR66 USER GUIDE - Manual (Page 9)

DR66 & DR128 Installer User Guide 9
Basic Principles
Audio Inputs and Outputs
The DR66 and DR128 audio mix processors accept any level of microphone or line level input
signals. These are pre-amplified and adjusted to the correct internal operating level required by
the processor using the rear panel and internal gain trimmers and pad jumper links. If required
phantom power can be independently selected for each mic input using internal links. The output
level is adjusted using internal trimmers or jumper links before they are differentially balanced and
sent to the XLR output connectors.
Digital Signal Processing
The DR performs its signal processing in the digital domain by first converting the analog audio
inputs to digital signals using A to D converters. The digital audio is then passed through a series
of Digital Signal Processing Engines before being converted back to analogue audio using D to A
converters. It is the Digital Signal Processing Engines that give the DR its power and versatility.
The Basic DR contains 2 Digital Signal Processing Engines (PE’s) as standard.
The first PE implements the Matrix Processor whose configuration is always fixed. The Matrix
Processor provides the input and output faders, signal meters, crosspoint matrix with variable gain
at each crosspoint, output protection limiters, multiple priority ducker, automatic mic mixer and the
‘soft’ insert points for the signal processing.
The second PE is available for the installer to configure the signal processing according to the
specific requirements of the installation. Signal Processing resources such as Parametric and
Graphic EQs, Gates and Compressors with full parameter control are provided in ‘Resource Racks’
one of which can be selected and loaded into the PE.
Resource Racks
A ‘resource rack’ is much like an equipment rack with various EQ, dynamic and other signal
processing devices loaded. Different combinations of processing devices can be loaded into the
PE in the same way as you can fill a 19” rack cabinet. There is a finite ‘space’ available. Many
rack combinations are available so you can choose that best suited to your application. A list of
the available resource racks is detailed in the WinDR Help menu Reference topic.
DSPx Resource Expander Option
Further signal processing capability is available by fitting DSPx plug-in expander cards. The DR66
accepts one expander, the DR128 accepts up to two. Each provides an additional 2 Processing
Engines. Thus up to 6 PE’s can be fitted with 5 of these available for custom-configured signal
processing by loading the best suited resource racks.
DSPd Delay Option
In addition to the DSPx expander cards a DSPd Delay option card can be fitted. This provides up
to 0.68 seconds (680mS) of signal delay on each output channel.
Controlling the DR
The level, routing and signal processing parameters can be assigned and configured using the
provided Allen & Heath WinDR System Manager software running on a PC. The front panel and
remote ‘soft’ keys are assigned according to required operator function such as level
increment/decrement, mute or patch recall. This is explained in the Help file provided with the
software. The RS232 serial port interfaces with the PC, communicates with industry standard
remote controllers using the Allen & Heath SysNet protocol or provides the gateway for networked
PC control. A multipin connector provides the interface to the remote switches.
How the DR is Used
The installer connects up the system, matches the audio interface using the internal trimmers,
configures the parameters using a PC, assigns and labels the panel and remote key functions,
disconnects the PC and leaves the unit ready for day to day operation. The operator has limited
control as defined by the installer. The system settings remain protected. The installer can archive
the configuration and edit the settings off-line. Updated versions of operating software available
from Allen & Heath can be easily loaded into the unit to take advantage of new features… Absolute
flexibility yet simple to install and use!