Lectrosonics DMPA12 User manual

DMPA12
Digital Power Amplifier
REFERENCE MANUAL
Rio Rancho, NM, USA
www.lectrosonics.com
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DMPA12 Digital Power Amplifier
LECTROSONICS, INC.2

Reference Manual
Rio Rancho, NM 3
Important Safety Instructions
This symbol, wherever it appears, alerts you to the presence of uninsulated dangerous voltage inside the
enclosure -- voltage that may be sufficient to constitute a risk of shock.
This symbol, wherever it appears, alerts you to important operating and maintenance instructions in the
accompanying literature. Please read the manual.
1) Read these instructions.
2) Keep these instructions.
3) Heed all warnings.
4) Follow all instructions.
5) Do not use this apparatus near water.
6) Clean only with a dry cloth.
7) Do not block any ventilation openings. Install in accordance with the manufacturer’s instructions.
8) Do not install near any heat sources such as radiators, heat registers, stoves, or other apparatus (including
amplifiers) that produce heat.
9) Do not defeat the safety purpose of the polarized or grounding-type plug. A polarized plug has two blades with
one wider than the other. A grounding type plug has two blades and third grounding prong. The wider blade
or the third prong are provided for your safety. If the provided plug does not fit into your outlet, consult an elec-
trician for replacement of the obsolete outlet.
10) Protect the power cord from being walked on or pinched particularly at plugs, convenience receptacles, and
the point where they exit from the apparatus.
11) Only use attachments/accessories specified by the manufacturer.
12) Use only with the cart, stand, tripod, bracket, or table specified by the manufacturer, or sold with the apparatus.
When a cart is used, use caution when moving the cart/apparatus combination to avoid injury from tip-over.
13) Unplug this apparatus during lightning storms or when unused for long periods of time.
14) Refer all servicing to qualified service personnel. Servicing is required when the apparatus has been dam-
aged in any way, such as power-supply cord or plug is damaged, liquid has been spilled or objects have fallen
into the apparatus, the apparatus has been exposed to rain or moisture, does not operate normally, or has
been dropped.
15) WARNING -- TO REDUCE THE RISK OF FIRE OR ELECTRIC SHOCK, DO NOT EXPOSE THIS APPARA-
TUS TO RAIN OR MOISTURE.

DMPA12 Digital Power Amplifier
LECTROSONICS, INC.4
Note: This equipment has been tested and found to comply with the limits for a
Class A digital device, pursuant to Part 15 of the FCC Rules. These limits are
designed to provide reasonable protection against harmful interference when the
equipment is operated in a commercial environment.
This equipment generates, uses, and can radiate radio frequency energy and,
if not installed and used in accordance with the instruction manual, may cause
harmful interference to radio communications.
Operation of this equipment in a residential area is likely to cause harmful inter-
ference in which case the user will be required to correct the interference at this
own expense.

Reference Manual
Rio Rancho, NM 5
Contents
Important Safety Instructions.............................................................................................................................................................3
General Overview ................................................................................................................................................................................6
DMPA12 System Configuration..........................................................................................................................................................8
DMPA12 Functional Block Diagram ...................................................................................................................................................9
Output Processing .............................................................................................................................................................................10
DMPA12 Controls and Features.........................................................................................................................................................11
Rear Panel .........................................................................................................................................................................................12
Installing LecNet2 Software and USB Driver ....................................................................................................................................13
USB Driver Installation (Windows 2000)............................................................................................................................................15
Using the Update Wizard ...................................................................................................................................................................16
Initial Setup ..........................................................................................................................................................................................18
Connection.........................................................................................................................................................................................18
DMPA12 System Setup Tabs...............................................................................................................................................................19
Activity Tab .........................................................................................................................................................................................19
Source Tab .........................................................................................................................................................................................20
Delay Tab ...........................................................................................................................................................................................21
Filters Tab...........................................................................................................................................................................................22
Compressor Tab.................................................................................................................................................................................24
Gain / Level Tab .................................................................................................................................................................................26
Limiter Tab..........................................................................................................................................................................................28
Rear Panel Control Tab ......................................................................................................................................................................30
DMPA12 Menus and Functions ..........................................................................................................................................................34
Setting up Front Panel controls..........................................................................................................................................................34
DMPA12 Serial Interface and General Commands ...........................................................................................................................36
DMPA12 General Commands............................................................................................................................................................36
DMPA12 Output Compressor Commands .........................................................................................................................................43
DMPA12 Output Limiter Commands ..................................................................................................................................................44
DMPA12 Programmable I/O Commands ...........................................................................................................................................45
DMPA12 Front Panel Control .............................................................................................................................................................48
DMPA12 Rear Panel Control Commands ..........................................................................................................................................50
DMPA12 Command Grammar Rules..................................................................................................................................................52
Macros and Macro Control .................................................................................................................................................................53
Rear Panel Control with Hardware.....................................................................................................................................................54

DMPA12 Digital Power Amplifier
LECTROSONICS, INC.6
General Overview
The architecture of a LecNet 2 sound system is built
around a powerful digital matrix and bus structure com-
mon to all DM Series components interconnected in a
system. Data and audio signals are shared among the
components through a digital bus called DANI (Digital
Audio Network Interface).
In order to understand the power and functions avail-
able with this architecture it is helpful to think of the
matrix as a separate entity from the hardware. Con-
ceptually, a DM processor is simply a hardware-based
tap into the digital matrix to interface various types of
microphones and audio equipment into the signal flow.
The DANI bus interconnects the processors to allow
them to share information about each input and output
and to distribute the audio.
Multiple DM processors are “stacked” to configure
larger systems, with one unit configured as the Mas-
ter at the “top” and the others as Slaves. There is no
limit to the number of units that can be stacked to add
inputs to a system. The number of outputs is limited to
a maximum of 24. Literally hundreds of inputs can be
configured with no “gas gauge” for DSP resources and
still less than 4 ms of latency. The choice of processor
model determines the number of final mix outputs at the
Master unit at the top of the stack.
When multiple DM processors are stacked, each unit
participates with the digital structure in several ways:
• Delivering audio signals from its input terminals into
the forward-propagated submix bus
• Passing back-propagated final mix signals from the
unit above it to the next unit below it
• Applying gain and signal processing to the audio
signals at its input terminals
• Delivering audio signals to its output terminals as
selected by the setup
• Applying signal processing to the signals routed to
its output terminals
• Receiving and transmitting data required for the
automatic mixing process in the matrix
The digital matrix is common to all processors in
the stack, with automatic mixing taking place at the
crosspoints in the digital matrix. The output of each
crosspoint is then available at a variety of output termi-
nals on various processors in the stack.
The DMPA12 digital power amplifier takes its input from
the DANI bus, with each output able to source from the
back or forward propagated signals (see block diagram
on page 8). This architecture provides exceptional flex-
ibility to accommodate a wide variety of applications.
Automatic Mixing Matrix
DM Series
Processor
Master
Slave
Slave
DM Series
Processor
DM Series
Processor

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Rio Rancho, NM 7
The LecNet 2 product family includes a variety of com-
ponents to address a wide variety of applications. Differ-
ent processor models interface with the digital matrix in
different manners.
Four basic matrix processor models are available:
• DM812 8 in/12 out
• DM1612 16 in/12 out
• DM1624 16 in/24 out
• DM84 8 in/4 out
Each of these models provides mic/line inputs, exten-
sive signal processing and differential balanced outputs.
Outputs are forward propagated to the Master unit in a
stack, and the first 12 outputs are also back propagated
to the Slaves in the system.
The DMTH4 telephone hybrid and DM84 processor
contribute to all 24 forward propagated channels deliv-
ered to the Master in the system, even though each of
them have only 3 or 4 physical outputs. The signals for
these 3 or 4 outputs are selected from the first 12 final
mixes back propagated from the Master.
Signal flow through the DANI bus
Master
Slave
Slave
Slave
Slave
EXPANSION
A B
TX RX
RX TX
EXPANSION
A B
TX RX
RX TX
EXPANSION
A B
TX RX
RX TX
EXPANSION
A B
TX RX
RX TX
EXPANSION
A B
TX RX
RX TX
Audio Final Mix and
Data Back Propagation
Audio Submix and
Data Forward Propagation
The DMPA12 digital power amplifier takes its inputs
from the DANI bus. It can access either the first 12 back
propagated signals from the system Master unit or the
24 forward propagated channels.
The output amplifiers are a Class D type in a differential
balanced configuration with each device providing two
channels, sharing a ground on a common connector.
The device is impervious to damage from shorts or
thermal overload, and can drive loudspeaker loads from
4 ohms and up. The outputs can also be wired in paral-
lel to double the available output power.
Because of the high efficiency of the Class D design,
no special ventilation or fans are necessary, even in
continuous duty at any power level.

DMPA12 Digital Power Amplifier
LECTROSONICS, INC.8
Two DMPA12 units configured as Master and Slave
at top of stack to handle up to 24 outputs
Slave
Slave
Slave
Slave
Slave
EXPANSION
A B
TX RX
RX TX
EXPANSION
A B
TX RX
RX TX
EXPANSION
A B
TX RX
RX TX
EXPANSION
A B
TX RX
RX TX
EXPANSION
A B
TX RX
RX TX
DMPA12 Slave
EXPANSION
A B
TX RX
RX TX
DMPA12 Master
EXPANSION
A B
TX RX
RX TX
Output Channels 1 - 12
Output Channels 13 - 24
Audio Submix and
Data Forward Propagation
DMPA12 configured as Slave at bottom of stack
Master
Slave
Slave
Slave
DMPA12 Slave
EXPANSION
A B
TX RX
RX TX
EXPANSION
A B
TX RX
RX TX
EXPANSION
A B
TX RX
RX TX
EXPANSION
A B
TX RX
RX TX
EXPANSION
A B
TX RX
RX TX
Audio Final Mix and
Data Back Propagation
Output Channels 1 - 12
Back Propagation - 12 channels
The DMPA12 digital power amplifier is
typically configured as a Slave in the
system using the first 12 back propa-
gated final mix signals labeled “Final
Mix” in the GUI.
See the RED signal path.
DMPA12 System Configuration
Forward Propagation - 24 channels
If more than 12 outputs need to be
amplified, two DMPA12 units can be
configured at the top of the stack, one
as a Master and one as the uppermost
Slave. In these positions, both units
can make use of the forward propagat-
ed signals from the Slave units below
them labeled “FP Main Mix” in the GUI.
See the BLUE signal path.
24 Channels
12 Channels

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Rio Rancho, NM 9
SHARC is a registered trademark of
Analog Devices, Inc.
USB
Port
RS-232
Port
Prog I/O
Port
Micro
Controller
Prog I/O Conn
DB25
LecNet 2 Conn
1/8 '' Jack
Front & Rear
USB B Conn
Control Signals
8
11
12
A/D
Output Volume Control Pots
12
Tx
Tx
Rx
Rx
Digital
Audio
Network
Interface
(DANI)
12 + 2 Submix + Mix Control
12 + 2 Submix + Mix Control
12 + 2 Mix + Mix Control
12 + 2 Mix + Mix Control
Sync Audio Frame Sync
Quad RJ-45 Conn Pink Noise Generetor
1 kHz Tone Generator
Third Generation
SHARC
®
DSP
Out 1
Out 2
Out 3
Out 4
12 output tricolor
signal indicator
LEDs
Signal Processing D/A
Signal Processing D/A
Signal Processing D/A
Signal Processing D/A
Signal Processing D/A
Signal Processing D/A
Signal Processing D/A
Signal Processing D/A
Signal Processing D/A
Signal Processing D/A
Signal Processing D/A
Signal Processing D/A
Out 12
Out 11
Out 10
Out 9
Out 8
Out 7
Out 6
Out 5
Off: No signal
Green: Signal present
Orange: Compressor active
Blinking orange: Fault
Red: Limiter active
Blinking red: Channel muted at front panel
DMPA12 Functional Block Diagram

DMPA12 Digital Power Amplifier
LECTROSONICS, INC.10
Output Processing
Extensive signal processing is available at each output,
adding to the processing available in the mixer/proces-
sors in the system. This is especially useful when a
variety of loudspeaker types are being used.
Output Source Select
The digital matrix delivers the audio signals used in
normal operation. The pink noise source can be used
for sound masking during operation, and for equaliza-
tion during setup. The tone generator is used for level
adjustments and signal routing diagnostics.
Output Signal Processing Stages
Each output channel provides a delay, nine filters, plus
a compressor and limiter to idealize the channel for
its function in the sound system. (See Typical Output
Signal Processing Block.)
Digital Delay
Delay on the output signal is normally used for time
alignment when loudspeakers are positioned in different
locations with overlapping coverage patterns that cause
comb filtering. The signal can be delayed up to 200 ms
in 0.5 ms increments to eliminate comb filtering and
improve intelligibility.
Filters
Up to nine filters can be implemented at each output to
idealize the output channel equalization and implement
crossover networks for bi-amped or tri-amped loud-
speaker systems.
The filter types include:
Low pass
High pass
Band pass
Parametric EQ
Low shelving
High shelving
Filter slopes can be selected with 6 or 12 dB per octave
Butterworth or Bessel parameters. Multiple filters can
be assigned to creater steeper slopes in 6 dB steps.
Compressor
A versatile compressor is provided at each output to
control the average level and dynamics of the audio sig-
nal, and restrict the maximum output level to optimize
the channel for its purpose.
Compressor adjustment parameters include:
Threshold
Time constant
Compression ratio
Makeup gain
Limiter
A sophisticated limiter with adjustable threshold and
time constant parameters can be set up for each output,
which is normally used to protect a loudspeaker system
and reduce distortion and amplifier overload.
Limiter adjustment parameters include:
Threshold
Time constant
The limiter implementation is based on an RMS level
detector controlled by a single time constant parameter.
This is an adaptive design which responds to vary-
ing rates of change in the signal level by dynamically
adjusting the attack and release times for best perfor-
mance.
Output Gain and Level Indicator
The level of each output can be adjusted over the full
range in 1 dB steps. A bar graph is provided in the GUI
to accurately indicate the output level as it operates.
See the detailed description on page 26 under the topic
entitled Gain/Level Tab.
Typical Output Signal Processing Block
Activity Indicator
Output Gain
-70 - +20 dB
1 dB steps
Nine Filter
Stages
Delay Compressor Limiter
Level Meter
Off, LP, HP, BP,
PEQ, LS, HS
6 or 12 dB/oct.
Butterworth or Bessel
when applicable
0 – 200 ms
0.5 ms steps
Threshold
Comp. Ratio
Time Constant
Indicator
Activity Indicator
Gain Reduction Indicator
Threshold
Time Constant
One of 12 Output Signal Processing Blocks

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DMPA12 Controls and Features
Front Panel
USB Ports
Standard USB connectors are provided on front and
rear panels for setup and control of the DM from a
computer using a Windows Vista, XP or 2000* operating
system.
MODE Switch
The MODE Switch is used for two purposes:
• During power up to switch the unit temporarily from
Slave to Master to enable access with a computer
to make changes in settings
• To set the unit into a Software Update mode for
updating the firmware
If a unit configured to run in a slave mode doesn’t detect
a master unit on power up, it will refuse to boot and
the Status LED will blink rapidly. In this case, pressing
the MODE switch will force the unit to boot up tempo-
rarily as a master to allow settings to be examined or
changed. Cycling the power returns the unit to the slave
mode.
Pressing and holding the MODE switch while power-
ing up the unit places it in Software Update mode. The
Status LED will blink slowly once a firmware update is
initiated, then goes out when the process is completed.
Cycling the power exits the Software Update mode and
returns the unit to normal operation.
Front Panel Gain Controls
The gain of output audio channels is adjustable with
control knobs on the front panel of the DMPA12. This
feature is useful for system setup and adjustment, and
may be left enabled to allow users to “touch up” gains
as needed during operation. Gain can be increased or
decreased within a range which is centered around 0
dB (unity) gain.
The range of adjustment for each channel is individually
programmable using the Control Panel GUI (in Device
Setup Menu) or Lecnet2 serial commands. Changes
made to the gain range settings take effect immediately
and are global in scope - the same settings are in effect
no matter what memory “preset” is loaded. The default
range is 30 dB (+/- 15 dB).
Any or all of the front panel gain controls may be
“locked out” to prevent unauthorized changes to the
system. This is also done using the Control Panel GUI
(in Device Setup Menu) or Lecnet2 serial commands.
Changes made to the gain control lock settings take
effect immediately and are global in scope - the same
settings are in effect no matter what memory “preset” is
loaded.
NOTE: When the Front Panel Mute feature is
enabled, the minimum gain position has a special
meaning. The channel will be muted and the
associated activity indicator will blink RED to
warn the user that no audio is being passed. This
feature can be controlled using the supplied GUI
control panel or the serial command “fpmten.”
Front Panel Output Activity Indicators
These indicators reflect activity on the output audio
channels. Useful for setup and troubleshooting, these
tri-color LEDs are interpreted as follows:
• DARK channel is inactive
• GREEN audio present (level greater than -35
dBu)
• ORANGE output compressor is active
• RED output is in limiting
• BLINKING RED output has been muted using
front panel gain control
• BLINKING ORANGE a fault exists on the output
- check wiring for short circuits, etc.
* Windows Vista, XP and 2000 are trademarks of Microsoft
Corporation
If the STATUS LED
blinks at turn on,
press the MODE
button to change
it to Master status
temporarily.

DMPA12 Digital Power Amplifier
LECTROSONICS, INC.12
Rear Panel
POWER Plug
Standard NEMA 5-15 three-pin power plug capable of
accepting 100-240 VAC, 47-63 Hz.
RS-232 Port
Standard USB connector for setup and control of the
DM from a computer using a Windows Vista, XP or
2000* operating system.
USB Port
Standard USB connector for setup and control of the
DM from a Windows Vista, XP or 2000* computer sys-
tem with USB interface.
POWER
100-240V 50/60Hz 200W
This device complies with
Part 15 of the FCC rules.
Operation is subject to the
following two conditions: (1)
This device may not cause
harmful interference, and (2)
this device must accept any
interference received, including
interference that may cause
undesired operation.
MADE IN U.S.A.
12 CHANNEL POWER AMPLIFIER
1: GND
2: IN 1
3: IN 3
4: IN 5
5: IN 7
25
13
14
1
6: IN 9
7: IN 11
8: GND
9: OUT 1
10: OUT 3
11: OUT 5
12: OUT 7
13: GND
14: +5V
15: IN 2
16: IN 4
17: IN 6
18: IN 8
19: IN 10
20: +5V
21: OUT 2
22: OUT 4
23: OUT 6
24: OUT 8
25: +5V
PROGRAMMABLE
INPUTS / OUTPUTS
RS-232
LecNet 2
USB EXPANSION
A B
TX RX
RX TX
1 2
OUTPUT
3 4 5 6 7 8 9 10 11 12
Programmable Input and Output Ports
Programmable inputs or outputs used to enable control
over a variety of parameters or to indicate the current
state of a programmable input or other device settings.
DANI
DANI, or Digital Audio Network Interface, is used to
connect the digital audio outputs of the master and
slave units in stacked configurations.
Audio Outputs
Analog audio output connectors. Standard depluggable
jacks with output pairs sharing a common ground con-
nection in the center of the connector. The outputs are
a balanced differential type that can be used with or
without shielded cabling.
* Windows Vista, XP and 2000 are trademarks
of Microsoft Corporation.

Reference Manual
Rio Rancho, NM 13
Installing LecNet2 Software and USB Driver
Part of the LecNet2 software package is the control
panels for the DMPA12. This Graphic User Interface
(GUI) is designed to allow easy setup and monitoring of
the DMPA12 using a computer system running Win-
dows Vista, XP or 2000* operating systems.
Installing LecNet2 Software
1. Use the computer control panel to remove any previ-
ously installed versions of LecNet2 software. (This
will ensure you are using the latest release.)
2. Insert the LecNet2 program disk supplied with the
Venue Receiver into the CD-ROM drive on the com-
puter system that will be used to set up and control
the Venue Receiver. The CD should automatically
start the installation procedure.
3. If the CD doesn’t launch automatically, click “Start”
on the Windows Task Bar then click “Run...” and
enter the CD Drive number followed by “Setup.exe”
as shown above.
4. Follow the on-screen instructions to install the Lec-
Net2 software.
Installing the LecNet2 USB Driver
There are two methods of connecting a Windows-based
computer system to DM Series device, either via a USB
cable or an RS-232 cable. However, although the USB
port offers significantly increased speed and conve-
nience over standard RS-232 links, it does require the
installation of a LecNet2 USB driver.
The LecNet2 USB driver is not part of the standard Win-
dows®driver library. As a result, connecting a computer
system to a DMPA12 for the first time is different than
subsequent installations. There are a few minor differ-
ences between installing the LecNet2 USB drivers on a
Windows 2000 versus a Windows XP system.
USB driver installation (Windows XP)
When a DMPA12 is connected to a Windows XP com-
puter system for the very first time, the Windows®“New
Hardware Found Wizard” automatically opens.
First time installation
When a LecNet2 device is connected to the computer
system for the very first time, the Windows Found New
Hardware Wizard automatically opens. Use the follow-
ing procedure to install the LecNet2 USB driver using
the Wizard.
1. Place the LecNet2 Installation Disk in the computer
system’s CD-ROM drive.
2. On the first page of the Wizard, select the option
“Install from a list or specific location (Ad-
vanced)” and click Next> to continue.
3. Select “Search for the best driver in these loca-
tions.”, then check the box for “Search removable
media (floppy, CD-ROM...)” and click Next> to
continue.
* Windows Vista, XP and 2000 are trademarks of
Microsoft Corporation.

DMPA12 Digital Power Amplifier
LECTROSONICS, INC.14
Installing Additional DM Units
(or LecNet2 devices)
The Windows XP operating system regards all Lec-
Net2 devices as separate USB devices because
each has a unique serial number. Because of this,
Windows XP will want to install the USB driver every
time it encounters a LecNet2 device whose serial
number it does not recognize. However, if the Lec-
Net2 USB driver has already been installed at least
once before on the computer system, the process
is simplified because the LecNet2 installation disk
is not required. Use the following procedure if the
LecNet2 USB driver was previously installed on the
computer system.
1. On the first page of the Wizard, select “Install the
software automatically (Recommended)” and click
Next> to continue.
2. Windows will discover the previously installed driver
and it is likely that a dialog will open warning you
that the driver has not passed Windows Logo Test-
ing. Click Continue Anyway.
3. Wait while the status screen indicates the progress
of the installation. When the driver installation is
complete, the final page of the Wizard will appear.
Click Finish, and it will then be possible to connect
to the new LecNet2 device.
4. Windows will search the CD for the driver and when
it has found it, a dialog will likely open warning you
that the driver has not passed Windows Logo Test-
ing. This is OK, click Continue Anyway.
5. When the driver installation is complete, the final
page of the Wizard appears. Click Finish to com-
plete the LecNet2 USB driver installation. It is now
possible to connect to the LecNet2 device.

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4. When the driver installation is complete, the final
page of the Wizard appears. Click Finish.
USB Driver Installation (Windows 2000) -
Subsequent Installations
Once the LecNet2™USB driver is installed in a
Windows®2000 system device, subsequent LectNet2
USB devices will invoke the Found New Hardware
Wizard which will automatically load the LecNet2™
USB driver for the new device. Simply wait for the
message to appear stating that the new hardware is
installed.
USB Driver Installation (Windows 2000)
First Time Installation
When a LecNet2 device is connected to the computer
system for the very first time, the Windows Found New
Hardware Wizard automatically opens. Use the follow-
ing procedure to install the LecNet2 USB driver using
the Wizard.
1. Connect a cable between the DMPA12’s USB port
and the computer system (or one of the units in a
multiple unit installation). Place the LecNet2 Instal-
lation Disk in the computer system’s CD-ROM drive
and click “Next>” to display the next page.
2. Select “Search for a suitable driver for my device
(recommended)” and click “Next>” to continue to the
next page.
3. Check only “CD-ROM drives” then click “Next>” to
search the LecNet2CD for the USB driver. When it
is found, the LecNet2 device name will be displayed.
Click “Next>” to install the driver.

DMPA12 Digital Power Amplifier
LECTROSONICS, INC.16
Using the Update Wizard
The control panel can be used to download firmware
updates to the DMPA12. The Update Wizard guides you
through the steps of the update process. Since a failed
firmware update can leave the DMPA12 in an unus-
able state, it is important to follow the instructions in the
Update Wizard exactly.
NOTE: The update process is possible only using
a USB connection.
Firmware updates are distributed as a file whose name
follows the pattern “DMPA12-vX_X_X.update”, where
the “X_X_X” is a placeholder for a firmware version
number. For example a firmware update for version
number “1.1.12” would have the filename “DMPA12-
v1_1_12.update”. The dots normally used to separate
the three parts of the version number are replaced with
underscores in the filename for clarity.
Before starting make sure that the proper update file
is on hand. Connect the DMPA12 to a computer sys-
tem with a USB cable. Apply power to the DMPA12
and start the control panel software on the computer
system.
1. Choose File->Update... from the Control Panel Menu
Bar to open the Update DMPA12 Firmware Wizard.
2. The first page of the Wizard displays instructions
for the process of forcing the DMPA12 into update
mode. Follow them carefully and then click Next to
move to the SELECT DEVICE FOR UPDATE.
3. Any LecNet2 device detected on the USB port will
be listed. Click the DMPA12 unit to be updated. If
nothing appears on the list, or the unit to be updated
does not appear, check that the USB cable is con-
nected and click Refresh List.
Once the DMPA12 is selected, click Next to move to
SELECT UPDATE FILE.
4. Enter the file name for the update in the Path to Up-
date File field or click the browse button next to the
filename field to locate the update file. If the browse
button is clicked, the Select DMPA12 update file
dialog opens. If the file name was entered manually,
click Next.
If the browse button was clicked, select the update
file from the list and click Open to transfer that file-
name to the Path to Update File field.
Browse
button

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The entire process will take 15 minutes or so. A
notification message appears when the update is
finished. Follow the instructions in the message to
verify that the DMPA12 restarts with the updated
firmware version.
At this point the process is complete and the Wizard
will be ready to close. Click OK to dismiss the mes-
sage.
Click Finish to close the Wizard.
You can now connect to the newly updated DMPA12
with the control panel. The updated firmware ver-
sion number should appear in the status bar.
Then click Next.
5. Click Start Update to begin the firmware update. The
update is made in two stages, an update of the DM
DSP firmware, followed by an update of the control-
ler firmware.
The progress bar indicates the status of each up-
date stage.

DMPA12 Digital Power Amplifier
LECTROSONICS, INC.18
Initial Setup
The initial setup of a DMPA12 system is a simple four
step process:
• Set the unit to the Master mode, if necessary
• Connect the unit to the computer
• Select the signal Source using the GUI
• Set the Gain / Level using the GUI
LecNet2™ Software and the USB Driver must be in-
stalled before these steps can be completed.
Master/Slave Configuration
IMPORTANT: When operated as a “stand
alone” unit, the amplifier must be configured
as a Master before it will communicate with a
computer for setup.
First, connect ONLY the computer and a power cable
to the processor. Turn the power on and observe the
Status LED on the front panel. If the LED is blinking, the
unit is in the Slave mode and cannot start up because it
does not detect the presence of a Master unit.
If the STATUS LED blinks at power up, press the MODE
button to reset the unit temporarily to the Master mode.
The unit can then be connected to a computer and
configured as needed for operation.
Permanent changes to the Master/Slave status must
be made with the GUI interface. The front panel MODE
button is temporary only.
Connection
For simplicity, the instructions shown on this page
include only USB and RS-232 connections for setup
using a computer connected directly to the amplier. For
additional methods of connecting to the unit including
network and offline use, see the Installation Guide.
Connect the computer system to the DMPA12 unit us-
ing either the USB cable or the BLACK DB9 to stereo
mini (TRS 1/8”) cable for RS-232 communications.
(Both cables are included with the unit.)
NOTE: Only one DMPA12 unit at a time can be
connected to a serial port using the RS-232 cable.
Multiple units may be connected to a USB port
using a USB hub.
Turn the computer system on. After the boot sequence
is complete, click Start, then All Programs.
Select LecNet2, then select the DMPA12 control panel
from the list.
If the “Just a Reminder” dialog appears, click OK to
continue.
Click Connect on the Main Menu bar, then select the
type of connection between the computer system or
external control system and the DMPA12 unit.
USB - A standard interface that launches automatically
when the unit is connected and turned on. Front and
rear USB ports are provided.
Serial->COM1 - An RS-232 port for RS-232 com-
munications between the DMPA12 and the computer
sytsem, or for connecting the DMPA12 to an external
Crestron®or AMX® control system.
NOTE: The menu will list all serial ports detected
on the PC. However, many newer PCs have no
RS232 serial ports at all, so no serial connection
options will be listed.
Connecting via a USB port.
The STATUS LED will blink if the
unit is turned on and in the Slave
mode and there is no DM Master
processor connected to it.
Use the GUI
to make
permanent
changes to the
Master/Slave
status.

Reference Manual
Rio Rancho, NM 19
Activity Tab
The Activity Tab provides an “at a glance” monitoring
of output levels, when the amplifier is connected to a
computer system. This dynamic display indicates audio
signal levels at each output and the state of compressor
and limiter activity.
DMPA12 System Setup Tabs
Gain set on each channel is indicated in a window next
to each level meter. Gain can be adjusted by entering
a number directly into this window or with the vertical
slider at the right of each bar graph.
Channel Activity/Gain
LEDs, level meters, slider controls and gain value win-
dows for monitoring and controlling the output channels.
Level Meter
This is a true RMS level meter which displays the out-
put audio level in dBu after digital signal processing is
complete. The range of the meter is -40dBu to +20dBu,
referenced to the internal voltage scale prior to digital
to analog conversion and power amplification. Note:
The relationship between output level as indicated on
the level meter and power output into an 8 ohm load is
determined by these facts:
The maximum output of the digital to analog converter
(DAC) is 1 Vrms. So a full scale (+20 dBu) signal, after
digital to analog conversion, results in a 1 volt signal at
the input of the power amplifier.
The gain of the power amplifier stage is 20dB (for volt-
ages, a tenfold increase).
So a 1 kHz test tone shown by the level meter to have
a level of +20 dBu (full scale) will result in in a power
output of 12.5 watts into an 8 ohm resistive load. This is
because the full scale signal, after conversion, results
in a 1 volt input to the power amplifier. Since it has a
gain of 20dB, the power amplifier output is 10 volts,
developed across the 8 ohm load. From “power equals
voltage squared divided by resistance” we get 100/8 or
12.5 watts. A +10 dBu test tone will result in 1.25 watts,
a 0 dBu test tone will result in 0.125 watts, and so on.
Channel Activity/Gain
MU LED
Level Meter
C/L LEDs
Note: These values are based on “ideal”
components, including the load resistance.
Variations in real-world components will result in
measured power varying by as much as 0.5dB
from calculated figures.
MU LED
Glows red when channel is muted.
C/L LEDs
Glows yellow if the output channel compressor is active,
or red if the output channel audio is in limiting.

DMPA12 Digital Power Amplifier
LECTROSONICS, INC.20
Source Tab
The controls on this tab allow the selection of a signal
source for each of the output channels. Normally, the
channel is fed a forward or back propagated signal from
either the main matrix or the expansion matrix. The
DMPA12 also contains two internal test signal genera-
tors that can be used for diagnostics or sound masking
as alternative signal sources for an output channel:
• Final Mix signals back propagated from the Master
unit above it in the system stack
• Forward propagated main mix signals from the
Slave unit below it in the system stack
• A pink noise source
• 1 kHz sine wave source.
If connected to a DMPA12, changes made in this tab
take effect immediately. As always, the changes are not
permanent unless the DMPA12 settings are stored to a
preset in nonvolatile memory.
Clicking on the Matrix button displays a pull down to
reveal all signals available from the main and expansion
matrices.
Output channel source controls
The output channel signal source is selectable here from 3 choices:
• Matrix
A signal from the DANI bus is used as the signal source. When the DMPA12 is operated as as a Slave in a multi-
unit system, one of the 12 back propagated final mixes from the main mix matrix should be selected, or one of the
2 back propagated expansion mixes from the expansion mix matrix. This is the usual case, however, when oper-
ated as the Master in a multi-unit system, the 24 forward propagated main mixes also become available as signal
sources. In this special case - and only in this case - it can make sense to drive outputs from a forward propagated
main mix rather than one of the back propagated Final Mixes.
• Pink Noise
A 0 dBu pink noise generator is used as the signal source.
• 1 kHz Tone
A 0 dBu 1kHz sine wave generator is used as the signal source
Back propagated Final Mix
signals available on pulldown
Forward propagated Main Mix
signals available on pulldown menu
Pink noise and tone generator sources