Kramer 905 User manual

Kramer Electronics, Ltd.
USER MANUAL
Model:
905
Power Amplifier

Contents
i
Contents
1Introduction 1
2Getting Started 1
2.1 Quick Start 2
3Overview 3
4Your 905 Power Amplifier 3
5Installing the 905 in a Rack 6
6Connecting the 905 Power Amplifier 7
6.1 Connecting the 905 via RS-232 8
7Operating the 905 Power Amplifier 8
7.1 Using the Front Panel Buttons 8
7.1.1 Adjusting the Volume 8
7.1.2 Muting the Output 8
7.1.3 Mixing the Input Signals 9
7.2 Using the Audio Control Program 9
7.3 Using Serial Commands 10
8Technical Specifications 11
9905 Commands in Protocol 3000 12
9.1 Operating Commands 12
9.2 Help Commands 12
9.3 Device Initiated Messages 12
9.4 Result and Error Codes 12
9.5 Basic Routing Commands 12
9.6 Audio Parameters Commands 13
9.7 Protocol 3000 Syntax 14
9.7.1 Host Message Format 14
9.7.1.1 Simple Command 14
9.7.1.2 Command String 14
9.7.1.3 Device Message Format 14
9.7.1.4 Device Long Response 14
9.7.2 Command Terms 14
9.7.3 Entering Commands 15
9.7.4 Command Forms 15
9.7.5 Command Chaining 15
9.7.6 Maximum String Length 16

KRAMER: SIMPLE CREATIVE TECHNOLOGY
Contents
ii
Figures
Figure 1: 905 Power Amplifier 4
Figure 2: Connecting the 905 Power Amplifier 7
Figure 3: Audio Control Window 10
Tables
Table 1: 905 Power Amplifier Functions 5
Table 2: 905 Technical Specifications 11
Table 3: Communication Parameters 11

Introduction
1
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 the video, audio, presentation, and
broadcasting professional 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 groups1
Thank you for purchasing the Kramer 905 Power Amplifier, which is ideal
for:
that are clearly
defined by function.
•Presentation rooms and multimedia applications for quick, local audio
amplification
•Personal audio listening (for example, a PC and portable CD player)
The package includes the following items:
•905 Power Amplifier
•Power cord2
•Windows®-based Kramer control software
•This user manual3
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
•Use Kramer high-performance high-resolution cables4
1 GROUP 1: Distribution Amplifiers; GROUP 2: Switchers and Matrix Switchers; 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; GROUP 11: Sierra Products
2 We recommend that you use only the power cord supplied with this device
3 Download up-to-date Kramer user manuals from our Web site at http://www.kramerelectronics.com
4 The complete list of Kramer cables is on our Web site at http://www.kramerelectronics.com

KRAMER: SIMPLE CREATIVE TECHNOLOGY
Contents
2
2.1 Quick Start
This quick start chart summarizes the basic setup and operation steps.

Overview
3
3
3 Overview
The Kramer 905 is a high-performance power amplifier for line-level stereo
audio signals. It accepts either a stereo audio signal on an RCA connector or
a balanced stereo audio signal on a terminal block connector. It delivers a
speaker output of 80 watts RMS per channel into a 4Ωload on a 10A 4-pin
terminal block connector.
The 905 features:
•Two input selector buttons
•Two buttons for adjusting the volume and a mute button
•An unbalanced stereo input on RCA connectors and a balanced
stereo input on a terminal block
•An RS-232 port
Control your 905:
•Directly, via the front panel push buttons
•By RS-232 serial commands transmitted by a touch screen system,
PC, or other serial controller
The 905 is housed in a 19” 1U enclosure and is powered by a universal AC
power supply.
To achieve the best performance:
•Use only good quality connection cables1
•Avoid interference from neighboring electrical appliances that may
adversely influence signal quality and position your Kramer 905
away from moisture, excessive sunlight and dust
to avoid interference,
deterioration in signal quality due to poor matching, and elevated
noise levels (often associated with low quality cables).
4 Your 905 Power Amplifier
Figure 1 and Table 1 define the 905.
1 Available from Kramer Electronics on our Web site at http://www.kramerelectronics.com

KRAMER: SIMPLE CREATIVE TECHNOLOGY
Your 905 Power Amplifier
4
Figure 1: 905 Power Amplifier

Your 905 Power Amplifier
5
5
Table 1: 905 Power Amplifier Functions
#
Feature
Function
1 INPUT SELECTOR 1,2 Buttons Press to select the input audio source 1 (unbalanced) or 2
(balanced)
2 Volume ↑↓ Buttons Press to increase or decrease the output volume
3 MUTE Button Press to turn off or turn on the audio output. The button
illuminates when the audio output is disabled
4 INPUT 1 Left and Right RCA Connectors Connect to the unbalanced stereo audio source
5 INPUT 2 Terminal Block Connector Connect to the balanced stereo audio source
6 SPKR OUT L+ L- / R+ R-Terminal
Block Connector
Connect to a balanced stereo acceptor (speakers)
7 RS-232 9-pin D-sub Connector Connects to a PC or serial controller
8 PROGRAM Switch Switch up before performing a firmware upgrade, leave
down for normal operation

KRAMER: SIMPLE CREATIVE TECHNOLOGY
Installing the 905 in a Rack
6
5 Installing the 905 in a Rack
This section provides instructions for rack mounting the 1U unit.

Connecting the 905 Power Amplifier
7
7
6 Connecting the 905 Power Amplifier
To connect the 905, as illustrated in the example in Figure 2, do the following:
1. Connect an unbalanced stereo audio source (for example, the unbalanced
output of the DVD 1 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 the DVD 2 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 power cord to the power socket and connect the cord to the
mains electricity (not shown in Figure 2).
5. If required connect a PC and/or controller to the RS-232 port, see section
6.1.
Figure 2: Connecting the 905 Power Amplifier

KRAMER: SIMPLE CREATIVE TECHNOLOGY
Operating the 905 Power Amplifier
8
6.1 Connecting the 905 via RS-232
You can connect to the 905 via an RS-232 connection using, for example, a
PC. Note that a null-modem adapter/connection is not required.
To connect to the 905 via RS-232:
•Connect the RS-232 9-pin D-sub rear panel port on the 905 unit via
a 9-wire straight cable (only pin 2 to pin 2, pin 3 to pin 3, and pin 5
to pin 5 need to be connected) to the RS-232 9-pin D-sub port on
your PC
7 Operating the 905 Power Amplifier
You can operate your 905 using:
•The front panel buttons (see section 7.1)
•The Audio Control program (see section 7.2)
•RS-232 serial commands transmitted by a touch screen system, PC,
or other serial controller (see section 7.3)
7.1 Using the Front Panel Buttons
The front panel buttons let you:
•Select an input, by pressing the INPUT 1 or INPUT 2 buttons
•Adjust the volume (see section 7.1.1)
•Mute the sound (see section 7.1.2)
•Mix the input signals (see section 7.1.3)
7.1.1 Adjusting the Volume
To adjust the volume of the output signal:
1. Press the up volume arrow (↑) to increase the volume.
2. Press the down volume arrow (↓) to decrease the volume.
7.1.2 Muting the Output
To temporarily turn off the output:
•Press the MUTE button. The button illuminates and the sound turns
off
To turn on the output:
•Press the MUTE button. The illumination turns off and the sound
turns on at the previous volume level

Operating the 905 Power Amplifier
9
9
7.1.3 Mixing the Input Signals
You can mix the input signals using the two INPUT SELECTOR buttons.
To mix the signals, do the following:
1. Press the selected input twice.
The other input button illuminates and both buttons enter the mixing mode.
2. Press and hold the selected input button for 2 or 3 seconds until it blinks.
3. Press the up and down arrows to adjust the mixing rate between the inputs.
To exit the mixing mode, press the selected input.
7.2 Using the Audio Control Program
The 905 Audio Control Program allows you to adjust the volume and to
operate equalization controls for treble, mid-level and bass that cannot be
adjusted from the front panel.
To use the Audio Control Program:
1. Download and install the program on your PC from the Kramer Web site.
2. Connect the PC to the 905 (see section 6.1).
3. Open the Audio Control program.
The Audio Control window appears (see Figure 3).
4. Connect the 905 to the correct COM port of the PC.
5. Choose an input line (1 or 2).
6. Make volume, equalization and balance adjustments by operating the sliders
in the window.
7. Turn loudness On and Off by checking or unchecking the Loudness
checkbox.

KRAMER: SIMPLE CREATIVE TECHNOLOGY
Operating the 905 Power Amplifier
10
Figure 3: Audio Control Window
7.3 Using Serial Commands
To operate your device using serial commands, you need to install Kramer's
control software that can be downloaded from the Kramer Electronics Web
site1
For an explanation of all control commands, see section
.
9.
1 Download control software from our Web site at http://www.kramerelectronics.com

Technical Specifications
11
11
8 Technical Specifications
905 technical specifications are shown in Table 2:
Table 2: 905 Technical Specifications1
INPUTS: 1 unbalanced stereo audio input on RCA connectors
1 balanced stereo audio input on a 5-pin terminal block connector
OUTPUTS: 1 speaker stereo audio output on a 4-pin terminal block connector
INPUT SENSITIVITY: 8Ω: 320mVpp (unbalanced), 690mVpp (balanced)
4Ω: 220mVpp (unbalanced), 780mVpp (balanced)
OUTPUT POWER: 40 W per channel into 8Ω, 80W per channel into 4Ω
MAX. VOLTAGE GAIN: 8Ω: 44dB (unbalanced), 37dB (balanced)
4Ω: 46dB (unbalanced), 34dB (balanced)
OUTPUT MUSIC POWER: 300W per channel into 4Ω
BANDWIDTH (-3dB): >20kHz
S/N RATIO: 93dB
CROSSTALK: -55dB @1kHz,
-43dB @20kHz
CONTROLS: Bass: -8.5dB to 12.5dB @100Hz;
mid: -9dB to 13dB @1kHz;
treble: -8dB to 12.5dB @10kHz;
balance: -12dB to 0dB;
volume: <-35dB to 35dB @1kHz
ADDITIONAL CONTROLS: Loudness: -9dB @500Hz,
-9dB @1kHz,
-8.5dB @15kHz
COUPLING: DC
AUDIO THD + NOISE: 0.2% @1kHz, 1V
AUDIO 2nd HARMONIC: 0.15% @1kHz
AMPLIFIER TYPE: Class D
POWER SOURCE: 100-240V AC, 2.1A
DIMENSIONS: 19" x 7" x 1U W, D, H
WEIGHT: 2.0kg (4.4lbs)
ACCESSORIES: Power cord
Table 3: Communication Parameters
RS-232 Protocol 3000 (Default)
Baud Rate: 9600
Data Bits: 8
Stop Bits: 1
Parity: None
Command Format: ASCII
1 Specifications are subject to change without notice

KRAMER: SIMPLE CREATIVE TECHNOLOGY
905 Commands in Protocol 3000
12
9 905 Commands in Protocol 3000
This section describes all commands sent to the 905. For an explanation of
the syntax and use of Protocol 3000, see section U9.7U.
9.1 14BOperating Commands
Following are the specific commands that the room controller (RC device)
sends to the 905 to operate the external devices.
9.2 15BHelp Commands
Command Syntax Response
Protocol handshaking #CR ~OKCRLF
9.3 16BDevice Initiated Messages
Command Syntax
Start message Kramer Electronics LTD. , Device Model Version
Software Version
Switcher actions:
Audio channel has switched (breakaway mode) AUD IN>OUT
9.4 17BResult and Error Codes
Syntax
Command ran successfully, no error. COMMAND PARAMETERS OK
Protocol Errors:
Syntax error ERR001
Command not available for this device ERR002
Parameter is out of range ERR003
Unauthorized access (command run without the
matching login).
ERR004
9.5 18BBasic Routing Commands
Command Syntax Response
Switch audio only AUD IN>OUT, IN>OUT, …
Short form: A IN>OUT, IN>OUT, …
AUD IN>OUT, IN>OUT, …RESULT
Switch audio only AUD IN>OUT, IN>OUT, …
Short form: A IN>OUT, IN>OUT, …
AUD IN>OUT, IN>OUT, …RESULT
Read audio connection AUD? OUT
Short form: A? OUT
AUD? *
AUD IN>OUT
AUD IN>1, IN>2, …
Parameter Description:
IN = Input number or '0' to disconnect output.

905 Commands in Protocol 3000
13
13
'
>
' = Connection character between in and out parameters.
OUT = Output number or '*' for all outputs.
9.6 Audio Parameters Commands
Command Syntax Response
Set simple audio
volume
VOLUME VOLUME
Short form: VOL VOLUME
VOLUME VOLUME RESULT
Increase/decrease
simple audio volume
VOLUME +/-
Short form: VOL +/-
VOLUME +/- RESULT
Read simple audio
level
VOLUME?
Short form: VOL?
VOLUME VOLUME
Advanced commands for controlling each stage of audio amplification:
Set audio bass level BASS CHANNEL, BASS
Short form: ADB CHANNEL, BASS
BASS CHANNEL, BASS
RESULT
Read audio bass level BASS? CHANNEL
Short form: ADB? CHANNEL
BASS CHANNEL, BASS
Set audio treble level TREBLE CHANNEL,TREBLE
Short form: ADT CHANNEL,TREBLE
TREBLE CHANNEL, TREBLE
RESULT
Read audio treble TREBLE? CHANNEL
Short form: ADT? CHANNEL
TREBLE CHANNEL, TREBLE
Set audio midrange MIDRANGE CHANNEL, MID_RANGE
Short form: ADM CHANNEL, MID_RANGE
MIDRANGE CHANNEL,
MID_RANGE RESULT
Read audio midrange MIDRANGE? CHANNEL
Short form: ADM? CHANNEL
MIDRANGE CHANNEL,
MID_RANGE
Set audio loudness LOUDNESS CHANNEL, LOUDNESS
Short form: ADS CHANNEL, LOUDNESS
LOUDNESS CHANNEL,
LOUDNESS RESULT
Read audio loudness LOUDNESS? CHANNEL
Short form: ADS? CHANNEL
LOUDNESS CHANNEL,
LOUDNESS
Mute audio MUTE MUTE-MODE MUTE MUTE-MODE RESULT
Read audio mute state MUTE? MUTE MUTE-MODE
Set balance mode BALANCE OUT-CHANNEL, BALANCE-LEVEL BALANCE OUT-CHANNEL,
BALANCE-LEVEL RESULT
Read balance mode BALANCE? OUT-CHANNEL BALANCE OUT-CHANNEL,
BALANCE-LEVEL
Parameter Description:
STAGE = ‘IN, ’OUT’
or numeric value of present audio processing stage. For example: ‘0’ for input level, ‘1’ for pre-amplifier, ‘2’ for
amplifier (OUT) etc.
CHANNEL = Input or Output #
VOLUME / BASS / TREBLE / MID_RANGE = Audio parameter in Kramer units, minus sign precedes negative
values.
++ increase current value,
-- decrease current value.
MIX =
‘0’ or ‘OFF’
‘1’ or ‘ON’

KRAMER: SIMPLE CREATIVE TECHNOLOGY
905 Commands in Protocol 3000
14
9.7 Protocol 3000 Syntax
Protocol 3000 is used to control the 905 via an RS-232 connection using a
PC, touch screen, other serial controller or RC type controller.
9.7.1 Host Message Format
Start Address (optional) Body Delimiter
# Destination_id@ Message CR
9.7.1.1 Simple Command
Command string with only one command without addressing:
Start Body Delimiter
# Command SP Parameter_1,Parameter_2,… CR
9.7.1.2 Command String
Formal syntax with commands concatenation and addressing:
Start Address Body Delimiter
# Destination_id@ Command_1 Parameter1_1,Parameter1_2,…|
Command_2 Parameter2_1,Parameter2_2,…|
Command_3 Parameter3_1,Parameter3_2,…|…
CR
9.7.1.3 Device Message Format
Start Address (optional) Body delimiter
~ Sender_id@ Message CR LF
9.7.1.4 Device Long Response
Echoing command:
Start Address (optional) Body Delimiter
~ Sender_id@ Command SP [Param1 ,Param2 …] result CR LF
CR = Carriage return (ASCII 13 = 0x0D)
LF = Line feed (ASCII 10 = 0x0A)
SP = Space (ASCII 32 = 0x20)
9.7.2 Command Terms
Command
A sequence of ASCII letters ('A'-'Z', 'a'-'z' and '-').
Command and parameters must be separated by at least one space.
Parameters
A sequence of alphameric ASCII characters ('0'-'9','A'-'Z','a'-'z' and some
special characters for specific commands). Parameters are separated by
commas.
Message string
Every command entered as part of a message string begins with a message
starting character and ends with a message closing character.

905 Commands in Protocol 3000
15
15
Note: A string can contain more than one command. Commands are
separated by a pipe ( '|' ) character.
Message starting character
'#' – For host command/query
'~' – For machine response
Device address (Optional, for K-NET)
K-NET Device ID followed by '@'
Query sign
'?' follows some commands to define a query request.
All outputs sign
'*' defines all outputs.
Message closing character
CR – For host messages; carriage return (ASCII 13)
CRLF – For machine messages; carriage return (ASCII 13) + line-feed
(ASCII 10)
Command chain separator character
When a message string contains more then one command, a pipe ( '|' )
character separates each command.
Spaces between parameters or command terms are ignored.
9.7.3 Entering Commands
You can directly enter all commands using a terminal with ASCII
communications software, such as HyperTerminal, Hercules, etc. Connect
the terminal to the serial, Ethernet, or USB port on the Kramer device. To
enter CR , press the Enter key.
( LF is also sent but is ignored by command parser).
For commands sent from some non-Kramer controllers like Crestron, some
characters require special coding (such as, /X##). Refer to the controller
manual.
9.7.4 Command Forms
Some commands have short name syntax in addition to long name syntax to
allow faster typing. The response is always in long syntax.
9.7.5 Command Chaining
Multiple commands can be chained in the same string. Each command is
delimited by a pipe character ( '|' ). When chaining commands, enter the
message starting character and the message closing character only once,
at the beginning of the string and at the end.

KRAMER: SIMPLE CREATIVE TECHNOLOGY
905 Commands in Protocol 3000
16
Commands in the string do not execute until the closing character is
entered.
A separate response is sent for every command in the chain.
9.7.6 Maximum String Length
64 characters

17
17
LIMITED WARRANTY
WHO IS PROTECTED?
WHAT IS COVERED AND WHAT IS NOT COVERED
WHAT WE WILL PAY FOR AND WHAT WE WILLNOT PAY FOR
HOW YOU CAN GET WARRANTY SERVICE
LIMITATION OFIMPLIED WARRANTIES
EXCLUSION OF DAMAGES
CAUTION!
Kramer Electronics (hereafter ) warrants this product free from defects in material and workmanship under the
following terms.
Kramer
HOW LONG IS THE WARRANTY
Labor and parts are warranted for seven years from the date of the first customer purchase.
Only the first purchase customer may enforce this warranty.
We will pay labor and material expensesfor covered items.We will not pay for the following:
The liability of Kramer for any effective products is limited to the repair or replacement of the product at our option. Kramer shall
not be liable for:
This warranty gives you specific legal rights, and you may also have other rights, which vary from place to place.
All products returned to Kramer for service must have prior approval. This may be obtained from your dealer.
This equipment has been testedtodeterminecompliance with the requirements of:
EN-50081: "Electromagnetic compatibility (EMC);
generic emission standard.
Residential,commercial and lightindustry"
EN-50082: "Electromagnetic compatibility (EMC) generic immunity standard.
Part 1: Residential, commercial and light industry environment".
CFR-47: FCC* Rules and Regulations:
Part 15: “Radio frequency devices
Subpart B Unintentional radiators”
Except as below, this warranty covers all defects in material or workmanship in this product. The following are not covered
by the warranty:
1. Any product which is not distributed by Kramer, or which is not purchased from an authorized Kramer dealer. If you are
uncertain as to whether a dealer is authorized, please contact Kramer at one of the agents listed in the Web site
www.kramerelectronics.com.
2. Any product, on which the serial number has been defaced, modified or removed, or on which the WARRANTY VOID
TAMPERED sticker has been torn,
3. Damage, deterioration or malfunction resulting from:
i) Accident, misuse, abuse, neglect, fire, water, lightning or other acts of nature
ii) Product modification, orfailure to followinstructions supplied with the product
iii) Repair or attempted repair by anyone not authorized by Kramer
iv) Any shipment of the product (claims must be presented to the carrier)
v) Removal or installation of the product
vi) Any other cause, which does not relate to a product defect
vii) Cartons, equipment enclosures, cables or accessories used inconjunctionwith theproduct
1. Removal or installationscharges.
2. Costs of initial technical adjustments (set-up), including adjustment of user controls or programming. These costs are the
responsibility of the Kramer dealer from whom the product was purchased.
3. Shipping charges.
1. To obtain service on you product, you must take or ship it prepaid to any authorized Kramer service center.
2. Whenever warranty service is required, the original dated invoice (or a copy) must be presented as proof of warranty
coverage, and should be included in any shipment of the product. Please also include in any mailing a contact name,
company, address, and a description of the problem(s).
3. For the name of the nearest Kramer authorized service center, consult your authorized dealer.
All implied warranties, including warranties of merchantability and fitness for a particular purpose, are limited in duration to
the length of this warranty.
1. Damage to other property caused by defects inthis product, damages basedupon inconvenience,loss ofuse of theproduct, loss
of time, commercialloss; or:
2. Any other damages, whether incidental, consequential or otherwise. Some countries may not allow limitations on how long an
implied warranty lasts and/or do not allow the exclusion or limitation of incidental or consequential damages, so the above
limitations and exclusions maynot applyto you.
Servicing the machines can only be done by an authorized Kramer technician. Any user who makes changes or
modifications to the unit without the expressed approval of the manufacturer will void user authority to operate the
equipment.
Use the supplied DC power supply to feed power to the machine.
Please use recommended interconnection cables to connect the machine to other components.
IF reattached, removed or otherwise interfered with.
* FCC and CE approved using STP cable (for twisted pair products)
NOTE:
Part 1: