Kramer 908 User manual

KRAMER ELECTRONICS LTD.
USER MANUAL
MODEL:
908
40W per Channel Stereo Audio
Amplifier
P/N: 2900-000537 Rev 6

908 – Contents
i
Contents
1Introduction 1
2Getting Started 2
2.1 Achieving the Best Performance 2
2.2 Safety Instructions 3
2.3 Recycling Kramer Products 3
3Overview 4
3.1 Defining the 908 40W per Channel Stereo Audio Amplifier 5
4Connecting the 908 7
4.1 Connecting Balanced/Unbalanced Stereo Audio Input/Output 8
4.2 Connect the 10V CONTROL Port to an External Controller 9
4.3 Connecting a PC via RS-232 9
4.4 Connecting the 908 via the Ethernet Port 10
5Operating the 908 12
5.1 Using the Front Panel Buttons 12
5.2 Using Serial Commands 13
5.3 Using the Embedded Web Server 13
5.4 Using the RC-IR3 Infrared Remote Controller 17
6Updating the 908 Firmware 18
7Default Communication Parameters 19
8Technical Specifications 20
9908 Commands in Protocol 3000 21
9.1 Operating Commands 21
9.2 Help Commands 21
9.3 Device Initiated Messages 21
9.4 Result and Error Codes 21
9.5 Basic Routing Commands 22
9.6 Audio Parameters Commands 22
9.7 Identification Commands 23
9.8 Network Setting Commands 24
9.9 Machine Information Commands 24
9.10 Protocol 3000 Syntax 25
Figures
Figure 1: 908 40W per Channel Stereo Audio Amplifier 5
Figure 2: Connecting the 908 40W per Channel Stereo Audio Amplifier 8
Figure 3: Balanced Stereo Audio Connection 8
Figure 4: Unbalanced Stereo Audio Input Connection 8
Figure 5: Unbalanced Stereo Audio Output Connection 8
Figure 6: Connecting the 10V VOL Terminal Block Connector 9
Figure 7: Connecting to a PC 9
Figure 8: Local Area Properties Window 10
Figure 9: Internet Protocol (TCP/IP) Properties Window 11
Figure 10: Java Test Page Success Message 13
Figure 11: Entering the IP Number in the Address Bar 14
Figure 12: Loading the Embedded Web Server 14
Figure 13: First Time Security Warning 15
Figure 14: The 908 Control Window 15
Figure 15: Control Settings 16
Figure 16: Ethernet Settings 16

908 - Introduction
1
1 Introduction
Welcome to Kramer Electronics! Since 1981, Kramer Electronics has been
providing a world of unique, creative, and affordable solutions to the vast range of
problems that confront video, audio, presentation, and broadcasting professionals
on a daily basis. In recent years, we have redesigned and upgraded most of our
line, making the best even better!
Our 1,000-plus different models now appear in 11 groups that are clearly defined
by function: GROUP 1: Distribution Amplifiers; GROUP 2: Switchers and Routers;
GROUP 3: Control Systems; GROUP 4: Format/Standards Converters; GROUP 5:
Range Extenders and Repeaters; GROUP 6: Specialty AV Products; GROUP 7:
Scan Converters and Scalers; GROUP 8: Cables and Connectors; GROUP 9:
Room Connectivity; GROUP 10: Accessories and Rack Adapters and GROUP 11:
Sierra Products.
Congratulations on purchasing your Kramer 908 40W per Channel Stereo Audio
Amplifier, which is ideal for the following typical applications:
Presentation rooms and multimedia applications for quick, local audio
amplification
Personal audio listening (for example, a PC and portable CD player)

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908 - Getting Started
2 Getting Started
We recommend that you:
Unpack the equipment carefully and save the original box and packaging
materials for possible future shipment
Review the contents of this user manual
Go to http://www.kramerelectronics.com to check for up-to-date
user manuals, application programs, and to check if firmware
upgrades are available (where appropriate).
2.1 Achieving the Best Performance
To achieve the best performance:
Use only good quality connection cables (we recommend Kramer high-
performance, high-resolution cables) to avoid interference, deterioration in
signal quality due to poor matching, and elevated noise levels (often
associated with low quality cables)
Do not secure the cables in tight bundles or roll the slack into tight coils
Avoid interference from neighboring electrical appliances that may adversely
influence signal quality
Position your Kramer 908 away from moisture, excessive sunlight and dust
This equipment is to be used only inside a building. It may only be
connected to other equipment that is installed inside a building.
i
!

908 - Getting Started
3
2.2 Safety Instructions
Caution:
There are no operator serviceable parts inside the unit
Warning:
Use only the Kramer Electronics input power wall
adapter that is provided with the unit
Warning:
Disconnect the power and unplug the unit from the wall
before installing
2.3 Recycling Kramer Products
The Waste Electrical and Electronic Equipment (WEEE) Directive 2002/96/EC
aims to reduce the amount of WEEE sent for disposal to landfill or incineration by
requiring it to be collected and recycled. To comply with the WEEE Directive,
Kramer Electronics has made arrangements with the European Advanced
Recycling Network (EARN) and will cover any costs of treatment, recycling and
recovery of waste Kramer Electronics branded equipment on arrival at the EARN
facility. For details of Kramer’s recycling arrangements in your particular country
go to our recycling pages at http://www.kramerelectronics.com/support/recycling/.
!

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908 - Overview
3 Overview
The Kramer 908 is a high-performance audio amplifier for line-level stereo audio
signals. It accepts either a stereo audio signal on RCA connectors or a balanced
stereo audio signal on a terminal block connector. It delivers a speaker output of
2x40 watts RMS per channel into an 8load on a 10A 4-pin terminal block
connector. The 908 features:
Two input selector buttons and a mute button
One gain knob for adjusting the audio output levels for loudness, bass,
middle, treble, balance and the volume
A USB connector for firmware upgrade
RS-232 and Ethernet ports
A 10V control port for adjusting the audio gain via an external connector (for
example, the Kramer RC-63A)
The 908 can be controlled:
Directly, via the front panel push buttons and adjustment knob
By RS-232 serial commands transmitted by a touch screen system, PC, or
other serial controller
Via an external 10V controller (for volume)
Via the Ethernet using the embedded Web server
Remotely, from the infrared remote control transmitter
The 908 is housed in a Kramer MegaTOOLS™ enclosure and is fed by a 24V DC
power supply.

908 - Overview
5
3.1 Defining the 908 40W per Channel Stereo Audio
Amplifier
This section defines the 908.
Figure 1: 908 40W per Channel Stereo Audio Amplifier
#
Feature
Function
1
INPUT 1 L and R RCA Connectors
Connect to the left and right unbalanced stereo
analog audio acceptor
2
INPUT 2 Terminal Block Connector
Connect to the balanced stereo audio source
3
OUTPUT Terminal Block
Connector
Connect to a balanced stereo acceptor (speakers)
4
10V VOL G, V, + Terminal Block
Connector
Connect to a controller (for example, the Kramer
RC-63A) to adjust the volume via the controller
5
RS-232 G Tx Rx Terminal Block
Connector
Control connector
6
ETHERNET Port
Connects to your LAN
7
FACTORY RESET Button
Press to return the device to its factory default
settings
8
PROGRAM Switch
Switch down before performing a firmware
upgrade, leave up (the default) for normal
operation
9
24V DC Connector
+24V DC for powering the unit
10
IR IN Receiver
Accepts IR remote commands
11
ON LED
Illuminates green when receiving power, flashes
when receiving IR commands
12
MUTE Button
Press to disable/enable the audio output. The
button illuminates when the audio output is
disabled
13
INPUT SELECTOR Buttons
Press to select the input audio source 1 or 2

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908 - Overview
#
Feature
Function
14
LOUDNESS Button
Press to select the loudness adjustment, adjust
with the level knob
15
BASS Button
Press to select the bass adjustment, adjust with
the level knob
16
MID Button
Press to select the mid- range adjustment, adjust
with the level knob
17
TREBLE Button
Press to select the treble adjustment, adjust with
the level knob
18
BALANCE Button
Press to select the balance between right and left
speakers, adjust with the level knob
19
VOLUME Button
Press to select the volume adjustment, adjust with
the level knob
20
Level Adjustment Knob
Increase and decrease the level of the previously
selected function. Press and hold to disable local
volume control and enable remote volume control.
Press and hold again to activate local volume
control (see Section 5.1)
21
PROGRAM (USB) Connector
Connect to a computer to upgrade the firmware

908 - Connecting the 908
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4 Connecting the 908
Always switch off the power to each device before connecting it to your
908. After connecting your 908, connect its power and then switch on
the power to each device.
To connect the 908, as illustrated in the example in Figure 2, (see the input/output
connections in Section 4.1) do the following:
1. Connect an unbalanced stereo audio source (for example, the unbalanced
stereo audio output of a DVD player) to the L and R INPUT 1 RCA
connectors.
2. Connect a balanced stereo audio source (for example, the balanced stereo
audio output of a DVD player) to the INPUT 2 terminal block connector.
3. Connect the OUTPUT terminal block to a pair of loudspeakers:
Connect the “L+” and the “L-” terminal block connectors to the left
loudspeaker, and the “R+” and the “R-” terminal block connectors to the right
loudspeaker. Do not ground the loudspeakers.
4. Connect the 24V DC power adapter to the power socket and connect the
adapter to the mains electricity (not shown in Figure 2).
5. If required, connect:
The 10V CONTROL terminal block connector to an external controller
(for example, the Kramer RC-63A) (see Section 4.2)
The RS-232 port to a PC and/or serial controller (see Section 4.3)
The Ethernet port to a PC or a network hub or router (see Section 4.4)
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908 - Connecting the 908
Figure 2: Connecting the 908 40W per Channel Stereo Audio Amplifier
4.1 Connecting Balanced/Unbalanced Stereo Audio
Input/Output
This section illustrates how to wire:
A balanced stereo audio connection, see Figure 3
An unbalanced stereo audio input connection, see Figure 4
An unbalanced stereo audio output connection, see Figure 5
Figure 3: Balanced Stereo
Audio Connection
Figure 4: Unbalanced
Stereo Audio Input
Connection
Figure 5: Unbalanced
Stereo Audio Output
Connection

908 - Connecting the 908
9
4.2 Connect the 10V CONTROL Port to an External
Controller
You can connect the 908 10V VOL terminal block connector to a controller (for
example, the Kramer RC-63A) as illustrated in Figure 6:
Figure 6: Connecting the 10V VOL Terminal Block Connector
4.3 Connecting a PC via RS-232
You can connect a PC (or other controller) to the 908 via the RS-232 terminal
block connector.
To connect a PC to a 908 unit, connect the RS-232 terminal block connector on the
908 unit to the RS-232 9-pin D-sub port on your PC, see Figure 7:
Figure 7: Connecting to a PC

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908 - Connecting the 908
4.4 Connecting the 908 via the Ethernet Port
To connect the 908 via the Ethernet port, do the following:
When connecting to the Ethernet port on a network hub or network router,
use a straight-through cable with RJ-45 connectors
When connecting to the Ethernet port of a PC, use a crossover cable with
RJ-45 connectors
If you are connecting the 908 directly to your computer (not through the network)
you may need to reconfigure the PC network settings.
To reconfigure the PC network settings:
1. Navigate to Start > Settings > Network Connections.
2. Click on the appropriate Local Area Connection.
3. Right-click the Local Area Connection and click Properties.
The Local Area Properties Window appears:
Figure 8: Local Area Properties Window

908 - Connecting the 908
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4. Select Internet Protocol (TCP/IP) and click Properties.
The Internet Protocol (TCP/IP) Properties Window appears:
Figure 9: Internet Protocol (TCP/IP) Properties Window
5. Click Use the following IP address and enter the IP address and Subnet
mask shown above. Click OK and OK to close both windows and save the
settings.

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908 - Operating the 908
5 Operating the 908
You can operate your 908 using:
The front panel buttons (see Section 5.1)
PC, touch screen system, or other serial controller via RS-232 serial
commands (see Section 5.2)
The Ethernet via the embedded Web server (see Section 5.3)
The included RC-IR3 Infrared Remote Controller (see Section 5.4)
5.1 Using the Front Panel Buttons
The front panel buttons let you:
Select an input, by pressing the INPUT 1 or the INPUT 2 button
Adjust the sound
Mute the sound by pressing the MUTE button
To adjust the sound of the output signal:
1. Press the sound component that you want to adjust (LOUD, BASS, MID,
TREBLE, BAL or VOLUME). The button illuminates.
2. Turn the adjustment knob to adjust the setting.
Note: To enable remote volume control via the 10V VOL connector (using for
example, the Kramer RC-63A), you must disable the local digital volume control by
pressing and holding the VOLUME button on the front panel for several seconds.
The LED flashes to indicate that remote control is enabled. In this mode, volume
control via software ("Set simple audio volume" P3000 command, see Section 9.6)
is disabled. To disable remote control, press and hold the VOLUME button and the
LED lights solid.

908 - Operating the 908
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5.2 Using Serial Commands
To operate your device using serial commands, you need to install Kramer's
control software.
Download control software from our Web site at http://www.kramerelectronics.com.
For an explanation of all control commands, see Section 9.
5.3 Using the Embedded Web Server
You can remotely operate the 908 using a Web browser via the Ethernet
connection (see Section 5.3). To be able to do so, you must use a supported Web
browser; Microsoft (V6.0 and higher), Chrome or Firefox (V3.0 and higher).
To check that Java is installed correctly and running, browse to:
http://www.java.com/en/download/help/testvm.xml
This page runs a test and displays a Java success (see Figure 10) or failure
message.
Figure 10: Java Test Page Success Message
If you do not see the success message, follow the instructions on the page to:
Load and enable Java
Enable Javascript in your browser
Make sure that your PC is connected via the Ethernet connection to the 908 (see
Section 4.4) and do the following:

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908 - Operating the 908
1. Open your Internet browser.
2. Enter the unit’s IP number or name in the Address bar of your browser.
If you are using DHCP, you must enter the name.
The default IP number is 192.168.1.39, and may be changed by the system integrator.
Figure 11: Entering the IP Number in the Address Bar
The following window appears:
Figure 12: Loading the Embedded Web Server
3. Check that Java and JavaScript is enabled in your browser.
The following window appears:

908 - Operating the 908
15
Figure 13: First Time Security Warning
4. Click Run.
The 908 Control Window opens (see Figure 14):
Figure 14: The 908 Control Window
5. To choose the desired input, click on Input 1 or Input 2 (see Figure 15).
Each input has its own set of audio adjustments.
6. To adjust each function, click and hold each slider and drag to the right to
increase or to the left to decrease the shown value.
7. To mute the output, check the Mute box.

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908 - Operating the 908
Figure 15: Control Settings
8. To change the Ethernet settings, click the Settings tab at the top of the
Control Window. The Ethernet settings display (see Figure 16):
Figure 16: Ethernet Settings
9. Make any necessary changes and click Save to save the settings.
10. To return to the Control Window, click 908 under the Kramer logo.

908 - Operating the 908
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5.4 Using the RC-IR3 Infrared Remote Controller
You can use the RC-IR3 remote controller to make some of the adjustments that
are made using the front panel buttons:
Loudness, bass, mid, treble and balance adjustments are not adjustable using the IR remote.
To choose an input, press button 1 or 2
To toggle muting, press the OFF button
To increase the volume, press + (►)
To decrease the volume, press –(◄)