JBL CSA-2120 User manual

CSA-2120
Public Address System
Amplifier User Guide
公共广播系统
功率放大器
用户手册
CS Commercial Solution Series

CSA-2120
Public Address System
Amplifier User Guide

This manual does not include all of the details of design, production, or variation of the equipment. Nor
does it cover every possible situation which may arise during installation, operation or maintenance.
The information provided in this manual was deemed accurate as of the publication date. However,
updates to this information may have occured.
Trademark Notice: JBL is registered trademark of JBL International. Other trademarks are the property
of their respective owners.
© 2012 JBL Incorporated, 8400 Balboa Blvd. Northridge, CA 91329 USA. All Rights Reserved.

1
Contents
Important Safety Instructions .............................................................................. 2
JBL DECLARATION OF CONFORMITY .............................................................. 4
1.0 Welcome ....................................................................................................... 5
1.1 Features .................................................................................................. 5
1.2 How to Use this Manual ......................................................................... 5
2.0 Setup ............................................................................................................ 6
2.1 Unpacking Your Amplifier . ..................................................................... 6
2.2 Installing Your Amplifier .......................................................................... 6
2.3 Ensuring Proper Cooling ........................................................................ 9
2.4 Choosing Input Wire and Connectors .....................................................9
2.5 Choosing Output Wire and Connectors ................................................10
2.6 Wiring Your Audio System .....................................................................11
2.7 Connect to AC Mains ............................................................................12
2.8 Protect Your Speakers ...........................................................................12
2.9 Startup Procedure .................................................................................12
3.0 Operation .................................................................................................... 13
3.1 Precautions ........................................................................................... 13
3.2 Front Panel Controls and Indicators ......................................................14
3.3 Rear Panel Controls and Connectors .................................................... 14
Appendix A: Optional Item - Transformer module............................................. 15
Appendix B: Specifications ............................................................................... 17
Appendix C: AC Power Draw and Thermal Dissipation..................................... 17
Appendix D: Contact Information ...................................................................... 18

2
IMPORTANT SAFETY INFORMATION
WARNING FOR YOUR PROTECTION
READ THE FOLLOWING:
KEEP THESE INSTRUCTIONS
HEED ALL WARNINGS
FOLLOW ALL INSTRUCTIONS
THE APPARATUS SHALL NOT BE EXPOSED TO DRIPPING OR SPLASHING
LIQUID AND NO OBJECT FILLED WITH LIQUID, SUCH AS VASES, SHALL
BE PLACED ON THE APPARATUS
CLEAN ONLY WITH A DRY CLOTH.
DO NOT BLOCK ANY OF THE VENTILATION OPENINGS. INSTALL IN
ACCORDANCE WITH THE MANUFACTURER’S INSTRUCTIONS.
DO NOT INSTALL NEAR ANY HEAT SOURCES SUCH AS RADIATORS, HEAT
REGISTERS, STOVES, OR OTHER APPARATUS (INCLUDING AMPLIFIERS)
THAT PRODUCE HEAT.
ONLY USE ATTACHMENTS/ACCESSORIES SPECIFIED BY THE
MANUFACTURER.
UNPLUG THIS APPARATUS DURING LIGHTNING STORMS OR WHEN
UNUSED FOR LONG PERIODS OF TIME.
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 a third grounding prong. The wide blade or
third prong are provided for your safety. If the provided plug does not fit your
outlet, consult an electrician for replacement of the obsolete outlet.
Protect the power cord from being walked on or pinched particularly at plugs,
convenience receptacles, and the point where they exit from the apparatus.
Use only with the cart stand, tripod bracket, or table specified by the manu-
facture, or sold with the apparatus. When a cart is used, use caution when
moving the cart/apparatus combination to avoid injury from tip-over.
Refer all servicing to to qualified service personnel. Servicing is required
when the apparatus has been damaged 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.
POWER ON/OFF SWITCH: For products provided with a power switch, the
power switch DOES NOT break the connection from the mains.
MAINS DISCONNECT: The plug shall remain readily operable. For rack-
mount or installation where plug is not accessible, an all-pole mains switch
with a contact separation of at least 3 mm in each pole shall be incorporated
into the electrical installation of the rack or building.
FOR UNITS EQUIPPED WITH EXTERNALLY ACCESSIBLE FUSE
RECEPTACLE: Replace fuse with same type and rating only.
MULTIPLE-INPUT VOLTAGE: This equipment may require the use of a dif-
ferent line cord, attachment plug, or both, depending on the available power
source at installation. Connect this equipment only to the power source
indicated on the equipment rear panel. To reduce the risk of fire or electric
shock, refer servicing to qualified service personnel or equivalent.
If connected to 240V supply, a suitable CSA/UL certified power cord shall
be used for this supply.
SAFETY INSTRUCTIONS
NOTICE FOR CUSTOMERS IF YOUR UNIT IS EQUIPPED WITH A POWER CORD.
WARNING: THIS APPLIANCE SHALL BE CONNECTED TO A MAINS SOCKET
OUTLET WITH A PROTECTIVE EARTHING CONNECTION.
The cores in the mains lead are coloured in accordance with the following code:
GREEN and YELLOW - Earth BLUE - Neutral BROWN - Live
As colours of the cores in the mains lead of this appliance may not correspond
with the coloured markings identifying the terminals in your plug, proceed as
follows:
•The core which is coloured green and yellow must be connected to the terminal
in the plug marked with the letter E, or with the earth symbol, or coloured green,
or green and yellow.
•The core which is coloured blue must be connected to the terminal marked N
or coloured black.
•The core which is coloured brown must be connected to the terminal marked
L or coloured red.
This equipment may require the use of a different line cord, attachment plug, or
both, depending on the available power source at installation. If the attachment
plug needs to be changed, refer servicing to qualified service personnel who
should refer to the table below. The green/yellow wire shall be connected directly
to the units chassis.
CONDUCTOR WIRE COLOUR
Normal Alt
LLIVE BROWN BLACK
NNEUTRAL BLUE WHITE
EEARTH GND GREEN/YEL GREEN
WARNING: If the ground is defeated, certain fault conditions in the unit or in the
system to which it is connected can result in full line voltage between chassis and
earth ground. Severe injury or death can then result if the chassis and earth ground
are touched simultaneously.
The symbols shown above are internationally accepted symbols that warn
of potential hazards with electrical products. The lightning flash with arrow-
point in an equilateral triangle means that there are dangerous voltages
present within the unit. The exclamation point in an equilateral triangle
indicates that it is necessary for the user to refer to the owner’s manual.
These symbols warn that there are no user serviceable parts inside the
unit. Do not open the unit. Do not attempt to service the unit yourself. Refer
all servicing to qualified personnel. Opening the chassis for any reason
will void the manufacturer’s warranty. Do not get the unit wet. If liquid is
spilled on the unit, shut it off immediately and take it to a dealer for service.
Disconnect the unit during storms to prevent damage.

3
ELECTROMAGNETIC
COMPATIBILITY
This device complies with part 15 of the FCC Rules and the Product
specifications noted on the Declaration of Conformity. Operation is
subject to the following two conditions:
•this device may not cause harmful
interference, and
•this device must accept any interference received, including inter-
ference that may cause undesired operation.
Operation of this unit within significant
electromagnetic fields should be avoided.
•use only shielded interconnecting cables.
U.K. MAINS PLUG WARNING
A molded mains plug that has been cut off from the cord is unsafe.
Discard the mains plug at a suitable disposal facility. NEVER UNDER
ANY CIRCUMSTANCES SHOULD YOU INSERT A DAMAGED OR CUT
MAINS PLUG INTO A 13 AMP POWER SOCKET. Do not use the mains
plug without the fuse cover in place. Replacement fuse covers can be
obtained from your local retailer. Replacement fuses are 13 amps and
MUST be ASTA approved to BS1362.
If you want to dispose this product, do not mix it with general
household waste. There is a separate collection system for used
electronic products in accordance with legislation that requires
proper treatment, recovery and recycling.
Private household in the 25 member states of the EU, in Switzerland and
Norway may return their used electronic products free of charge to designated
collection facilities or to a retailer (if you purchase a similar new one).
For Countries not mentioned above, please contact your local authorities for a
correct method of disposal.
By doing so you will ensure that your disposed product undergoes the neces-
sary treatment, recovery and recycling and thus prevent potential negative
effects on the environment and human health.
IMPORTANT SAFETY INFORMATION
MAGNETIC FIELD
CAUTION! Do not locate sensitive high-gain equipment such as preamplifiers
or tape decks directly above or below the unit. Because this amplifier has a
high power density, it has a strong magnetic field which can induce hum into
unshielded devices that are located nearby. The field is strongest just above and
below the unit.
If an equipment rack is used, we recommend locating the amplifier(s) in the
bottom of the rack and the preamplifier or other sensitive equipment at the top.

4
DECLARATION OF CONFORMITY
Manufacturer’s Name: Crown Audio Inc.
Manufacturer’s Address: 1718 W. Mishawaka Road
Elkhart, IN 46517 USA
declares that the product:
Product name: Amplifier
Product model: CSA-2120
conforms to the following Product Specifications:
Safety:
IEC60065-2001 (Audio, video and similar electronic apparatus -- Safety requirements)
GB8898-2001 (Audio, video and similar electronic apparatus -- Safety requirements)
EMC:
GB13837-2003 (Sound and television broadcast receivers and associated equipment)
- Radio disturbance characteristics
- Limits and methods of measurement
GB17625.1-2003 (The Limits for the harmonic current emissions caused by low-voltage electrical
and electronic equipments (equipment input current 16A per phase)

5
1.0 Welcome
The JBL® CSA-2120 power amplifier (hereafter called as the amplifier) is a professional
tool designed and built for installed sound applications. The amplifier is two-channel model
providing simple analog amplification, with a switch-mode universal power supply.
The amplifier includes a rack mounting kit. With the rack mounting kit, you can install the
amplifier to a cabinet or wall. A transformer module can be purchased for use in high
impedance distributed sound systems. If your loudspeaker system requires higher imped-
ance, the transformer module can be connected between the amplifier and loudspeaker
systems to obtain the impedance matching.
1.1 Features
• High power output, compact size, light weight
• Accurate, uncoloured sound with very low distortion for the best in music and voice
• Over heat auto protection
• Low voltage auto protection
• The auto-standby mode allows the amplifier to save energy
• Detachable Euroblock input and output
• Switch-mode universal power supply
1.2 How to Use This Manual
This manual provides you with necessary information to safely and correctly setup and
operate your amplifier. It does not cover every aspect of installation, setup or operation that
might occur under every condition.
We strongly recommend you read all instructions, warnings and cautions contained in this
manual.

6
2.0 Setup
2.1 Unpacking Your Amplifier
Please unpack and inspect your amplifier for any damage that may have occurred during
transit. If damage is found, notify the transportation company immediately. Only you can
initiate a claim for shipping damage. We will be happy to help as needed. Save the ship-
ping carton as evidence of damage for the shipper’s inspection.
We also recommend that you save all packing materials so you will have them if you ever
need to transport the unit. Never ship the unit without the factory pack.
WARNING: Before you start to set up your amplifier, make sure you read and observe the
Important Safety Instructions found at the beginning of this manual.
2.2 Installing Your Amplifier
CAUTION: Before you begin, make sure your amplifier is disconnected from the power
source and all level controls turned completely down (counterclockwise).
To install the amplifier, you can use one of the following approaches:
• Rack mount the amplifier with the rack mounting kit, see Figure 2.2.3 and Figure
2.2.4.
• Install the amplifer to the wall with the rack mounting kit, see Figure 2.2.5.
• Stack amps without using a cabinet. For amplifier dimensions, see Figure 2.2.1.
NOTE: When transporting, amplifiers should be supported at front.

7
Solution A: Rack Mounting an Amplifier and CST-2120 Transformer Module
To install an amplifier and a CST-2120 transformer module in your cabinet system, refer to
Figure 2.2.3 and follow the steps below:
1. Align two modules side by side, with the front panel towards the same direction.
2. Connect them with the flat bracket.
3. Attach an angle bracket to each side of the amplifier assembly with screws.
4. Install the amplifier assembly into the cabinet. For details of installation in the chassis
of the cabinet, refer to the user guide of your cabinet.
Figure 2.2.1 Dimensions
Figure 2.2.2 Rack Mounting Kit
Figure 2.2.3 Rack mounting an amplifier and CST-2120 Transformer Module
long angle bracket
flat bracket
angle bracket
Unit: mm/inches

8
Solution B: Rack Mounting Single Amplifier
To install single amplifier in your cabinet system, refer to Figure 2.2.4 and follow the steps
below:
1. Attach the long angle bracket to one side of the amplifier that you need to reserve as
dummy module with screws.
2. Attach an angle bracket to the side of the long angle bracket.
3. Attach an angle bracket to another side of the amplifier with screws.
4. Install the amplifier assembly into the cabinet. For details of installation in the chassis
of the cabinet, refer to the user guide of your cabinet.
Solution C: Wall Mounting
To install the amplifier to wall, refer to Figure 2.2.5 and follow the steps below:
1. Attach two angle brackets to both sides of the amplifier with screws.
2. Install the amplifier assembly to a flat and stable place on the wall with enough clear-
ance for heat dissipation.
Figure 2.2.4 Rack Mounting Single Amplifier
Figure 2.2.5 Wall Mounting

9
2.3 Ensuring Proper Cooling
When using an equipment rack, mount units directly on top of each other. DO NOT block
side air vents. The back of the rack should be open.
2.4 Choosing Input Wire and Connectors
We recommend using pre-built or professionally wired balanced line (two-conductor plus
shield) 22-24 gauge cables to connect the amplifier balanced input by using shipped two
3-pin Euroblock connectors, see Figure 2.4. Unbalanced lines may be used, but may result
in hum or RF noise very long cable runs.
You can also use RCA connectors to connect audio devices, for example, CD/DVD player.
However, you are not recommended to use RCA connectors and Euroblock connectors to
input sound signal at the same time.
NOTE: Custom wiring should only be performed by qualified personnel.
EUROBLOCK CONNECTORS
MONO SUM UP
R
L
STEREO
R
L
RCA CONNECTORS
G
G
G
G
Figure 2.4 Input Wiring
Note: You are not recommended to use RCA connectors and Euroblock connectors to input
sound signal at the same time.

10
2.5 Output Wiring
To drive distributed speaker systems designed to operate at 70V or 100V, connect the
amplifier to a CST-2120 transformer module with the jumper cable that shipped with the
CST-2120 transformer module, see Figure 2.5.1.
JBL recommends using pre-built or professionally wired, high-quality, two-conductor, heavy
gauge speaker wire. Speakers wires should be twisted cable, if possible. To prevent the
possibility of short-circuits, the wires should be stripped back no greater than 6 mm (1/4
inch), see Figure 2.5.2.
Suggested below are guidelines to select the appropriate size of wire based on the dis-
tance from amplifier to speaker. Check with local code as this may vary.
Distance Wire Size
Up to 25 ft. (7.6m) 16AWG
26-40 ft. (7.9-12.2m) 14AWG
Figure 2.5.1 Connecting To a CST-2120 Transformer Module
NOTE: If driving a 70V or 100V distributed speaker system, use the optional CST-2120
transformer module (see Appendix A).
输出 输出
TO
Speaker
TO
Speaker
Figure 2.5.2 Connecting to Speakers

11
2.6 Wiring Your Audio System
Typical input and output wirings are shown in Figure 2.6.
INPUTS: Connect input wiring for both channels.
OUTPUTS: Maintain proper polarity (+/–) on output connectors.
Connect Channel 1 loudspeaker’s positive (+) lead to Channel 1 positive (+) terminal of
amp; repeat for negative (–). Repeat Channel 2 wiring as for Channel 1.
The minimum impedance one of the amplifier channels can drive is 4 Ohms. Therefore,
you can connect up to four 16 Ohms speakers, or two 8 Ohms speakers, or one 4 Ohms
speaker to each amp channel.
输入
70Hz 高通滤波
限幅
自动待机（STBY） 输入
70Hz 高通滤波
限幅
输出 输出
输入功率 50W
100-240V~50/60Hz
输入
70Hz 高通滤波
限幅
自动待机（STBY） 输入
70Hz 高通滤波
限幅
输出 输出
输入功率 50W
100-240V~50/60Hz
Figure 2.6 Wiring Audio System
Professional audio system
Personal audio system

12
2.7 Connecting to AC Mains
Connect your amplifier to the AC mains power source (power outlet) with the supplied AC
power cord. First, connect the IEC end of the cord set to the IEC connector on the ampli-
fier; then, plug the other end of the cord set to the AC mains.
WARNING: The third prong of this connector (ground) is an important safety feature. Do
not attempt to disable this ground connection by using an adapter or other methods.
Amplifiers don’t create energy. The AC mains voltage and current must be sufficient to
deliver the power you expect. You must operate your amplifier from an AC mains power
source with not more than a 10% variation above or a 15% variation below the amplifier’s
specified line voltage and within the specified frequency requirements (indicated on the
amplifier’s back panel label). If you are unsure of the output voltage of your AC mains,
please consult your electrician.
2.8 Protecting Your Speakers
It’s wise to avoid clipping the amplifier signal. Not only does clipping sound bad, it can
damage high-frequency drivers. The built-in clip limiter prevents clipping.
Also, avoid sending strong subsonic signals to the amplifier. High-level, low-frequency
signals from breath pops or dropped microphones can blow out drivers. You can switch on
the highpass filters, and this avoids to send subsonic signals under 70 Hz to the amplifier.
The high-pass filter is also useful when using the CST-2120 transformer module into a line
of 70V or 100V distributed loudspeakers, to prevent distortion within the speakers due to
transformer saturation.
2.9 Startup Procedure
Use the following procedure when first turning on your amplifier:
1. Turn down the level of your audio source.
2. Turn down the level controls of the amplifier.
3. Power up the amplifier. The Power indicator should light.
4. Turn up the level of your audio source to an optimum level.
5. Turn up the Level controls on the amplifier until the desired loudness or power level is
achieved.
If you ever need to make any wiring or installation changes, don’t forget to disconnect the
power cord.

13
3.0 Operation
3.1 Precautions
Your amplifier is protected from internal and external faults, but you should still take the fol-
lowing precautions for optimum performance and safety:
1. Before use, your amplifier first must be configured for proper operation, including input
and output wiring hookup. Improper wiring can result in serious operating difficulties.
For information on wiring and configuration, please consult the Setup section of this
manual.
2. Use care when making connections, selecting signal sources and controlling the
output level.
3. Do not short the ground lead of an output cable to the input signal ground. This may
form a ground loop and cause oscillations.
4. WARNING: Never connect the output to a power supply, battery or power main. Electri-
cal shock may result.
5. Tampering with the circuitry, or making unauthorized circuit changes may be hazard-
ous and invalidates all agency listings.
6. Do not operate the amplifier with the red Clip LEDs constantly flashing.
7. Do not overdrive the mixer, which will cause clipped signal to be sent to the amplifier.
Such signals will be reproduced with extreme accuracy, and loudspeaker damage
may result.
8. Do not operate the amplifier with less than the rated load impedance. Due to the
amplifier’s output protection, such a configuration may result in premature clipping and
speaker damage.
9. Use the amplifier in a well-ventilated environment and do not use it at high operating
temperature. Failure of doing so will result in the auto disconnection from power supply
and the activation of over heat auto protection function. The power indicator will be
turned off, and nothing will be output from amplifier. In this case, turn down the volume
to the minimum, and the amplifier will resume working when the amplifier returns to
normal temperature. Turn the volume up to required level.
10. If the amplifier input voltage is too low, the low voltage protection function will be acti-
vated. The power indicator will be turned off.
CAUTION: JBL is not liable for damage that results from overdriving other system
components.

14
3.2 Front Panel Controls and Indicators
A. Level: Detented rotary level control, one per channel.
B. Meter Group (one per channel):
• Clip Indicator: Red LED turns at the threshold of audible distortion.
• Signal Indicator: Green LED flashes when a very low-level signal (Threshold
-40dB) is present at input. May be used for troubleshooting cable runs.
C. Power Indicator: On/off switch applies AC power to the amplifier.
3.3 Rear Panel Controls and Connectors
D. AC Line Connector
E. Output Connectors: 4-pin Euroblock connectors for dual loudspeakers.
F. Amplifier Parameter Switchers: Slide DOWN to turn on these functions. Slide UP to turn
them off. The parameter switchers are numbered as below:
1. CH1 70Hz highpass filter
2. CH2 70Hz highpass filter
3. CH1 peak limiter
4. CH2 peak limiter
5. Auto standby
G. RCA Connectors
H. Euroblock Connectors: Two 3-pin Euroblock connectors each accept a balanced or
unbalanced line-level input signal.
AC
B
输入
70Hz 高通滤波
限幅
自动待机（STBY） 输入
70Hz 高通滤波
限幅
输出 输出
输入功率 50W
100-240V~50/60Hz
D E F G
H
Figure 3.3 Rear View
Figure 3.2 Front View

15
Appendix A: Optional Item - Transformer Module
The rack-mountable JBL Commercial®CST-2120 transformer module provides impedance
and voltage matching from the CSA-2120 amplifier (with 4 Ohms or 8 Ohms outputs) to
drive 70V and 100V distributed speakers systems.
This unit allows amplifiers without direct 70V or 100V output capability to drive distributed
speaker systems designed to operate at those voltages.
Features
• Providing two channels of impedance matching for “Constant-Voltage” operation
• Providing 70V and 100V output when used with CSA-2120 amplifiers
• Allowing amplifiers without direct Constant-Voltage capability to be easily integrated
into distributed systems
• Detachable Euroblock input and output connector
CST-2120 Overview

16
Installation
CAUTION: Before you begin, make sure that the amplifier is disconnected from the
power source and all level controls are turned completely down (counter-clockwise).
1. If you need to mount the transformer module to rack, use a standard 19-inch (48.3-cm)
equipment rack (EIA RS-310B) . You can have the following options according to your
application:
• Rack mounting the transformer module with a CSA-2120 amplifier
• Rack mounting single unit
• Wall mounting
2. Connect the input of the transformer module to the output of the CSA-2120 amplifier with
the shipped 4-pin cable.
3. Determine the proper transformer module tap to use, based on the desired constant-
voltage of your system.
CST-2120 Connection