DP2140 Digital Signal Processor

Front Panel

Input Signal Indicators
A set of three pairs of LEDs indicate signal present, +4dBu and input clip for each channel. The signal present LEDs operate at approximately -40 dBu, giving a useful indication of even relatively low input signal levels. The +4 dBu LEDs are intended to show nominal operating level and can also be useful for setting system gain structure. Clip LEDs warn the user of input overload and operate at +19 dBu.

Preset Store and Recall
These controls provide access to the 45 presets stored within the device. Pressing the store button allows the user to name a preset and choose which memory location it will be held in. Pressing store button again completes the process. The Recall function operates in a similar way, pressing the recall button allows the user to select which preset they require, pressing the button for a second time, then confirming, recalls the new DSP settings.
Note that presets cannot be stored or recalled when Secure mode is activated.

Channel Select Buttons
The currently selected channel is displayed on the top left hand corner of the LCD. Pressing the channel buttons scrolls through the available input and output channels and finally through the utility functions and back to the default screen. If operating a stereo linked preset, the channel name will indicate the channel pairing. For example 'A+B' means both input A and B parameters. The name of the output will be shown briefly at the top of the display when stepping onto an output.

Edit Select Buttons
The currently selected edit parameter page is displayed on the bottom left corner of the LCD. Pressing the edit select buttons moves through the available parameters for the current input or output.

Text Display
Preset, channel, parameter and status information is shown on the 2 × 24-character text display. In most screens the currently selected channel is displayed on the upper line and the edit parameter on the lower line. To simplify the display and enhance security, some parameters or parameter pages are omitted when not relevant.

Parameter Knobs
Three velocity sensitive parameter knobs are used to adjust parameters shown on the display. Up to three parameters at a time are displayed on the screen. The parameter name is shown above the parameter value in each of the three screen sections. The parameter knobs have a fixed association with the screen sections; the rightmost parameter knob adjusts the rightmost parameter and so on.

Output Signal / Limiter Indication
Two LEDs are provided for each output channel. These show the signal level relative to the limiter threshold. The yellow LED will light when the signal is 6dB below the threshold and the red warning LED will light when the limiter threshold is reached.

Mute Buttons and Status LEDs
Each output has a mute button and associated mute status LED. Pressing the button toggles the mute on and off.
Note that the mute buttons do not function when the Secure mode is activated.

Secure Button (on the rear)
A momentary button is fitted behind the rear panel, between the output XLRs and the RS232 port. When activated, this will disable all the front panel controls so they cannot affect the signal path, making the unit secure against tampering. When in secure mode, the indicators still operate normally. Note that the communications port is still active in secure mode.

Rear Panel

Power Inlet
The LOGIC SYSTEM Digital series unit should be connected to a suitable mains electricity supply using the cable supplied. The processor has a switch mode power supply that is capable of operating with a nominal mains voltage of 85V to 240V, 50/60Hz without re-configuration.

Network Expansion Port
Where a future network card can be fitted.

Audio Input Connectors
All audio connections are fully balanced and wired pin-1 ground, pin-2 hot & pin-3 cold. The two inputs have pin-1 connected directly to the chassis and feed the signal processing chains. If an unbalanced source is used, a connection should be made between the pin-3 'cold' signal and the ground connection of the unbalanced source.

Audio Output Connectors
The processed outputs are impedance balanced, and wired pin-1 ground, pin-2 hot and pin-3 cold. An unbalanced input may be driven by connecting pin-3 'cold' signal to the ground connection of the unbalanced destination input. Note that output pin-1's are ground lifted at audio frequencies but connected to ground at RF for good EMC performance. The intention being that the amplifiers the processor is driving should be responsible for the grounding of their input cable shields.

Communications Port Connector
Logic System Digital series processor may be controlled entirely from another controller, typically a Personal Computer, running an application that is compliant with the ObCom standard. Connection will normally be made to the controller via this serial port connector. This port is also used for updating the firmware in the unit.
Note that the communications port is NOT disabled when the front panel is made secure using the secure button.