Inter-m PA-9348 User manual

Operation Manual
Public Address Power Amplifier
PA-9312/9324/9336/9348

Contents
Contents
Welcome
Warning.........................................................................................................................................1
Unpacking......................................................................................................................................2
Installation
Environment....................................................................................................................................2
Important Safety Instructions.............................................................................................................2
Features............................................................................................................................................3
Accessories.....................................................................................................................................3
Operation ........................................................................................................................................3
Front Panel ......................................................................................................................................4
Rear Panel .......................................................................................................................................5
Connecting Speakers.....................................................................................................................7
Applications ....................................................................................................................................8
Block Diagram ................................................................................................................................9
Specifications ................................................................................................................................11
Service
Procedures....................................................................................................................................12
Schematic.....................................................................................................................................12
Parts List .......................................................................................................................................12
Variations and Options ...............................................................................................................12
Warranty .......................................................................................................................................12
PUBLIC ADDRESS POWER AMPLIFIER

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PA-9312/9324/9336/9348
Welcome
Welcome
A personal welcome to you from the management and employees of Inter-M
All of the co-workers here at Inter-M are dedicated to providing excellent products with inherently good value,
and we are delighted you have purchased one of our products.
We sincerely trust this product will provide years of satisfactory service, but if anything is not to your complete
satisfaction, we will endeavor to make things right.
Welcome to Inter-M, and thank you for becoming part of our worldwide extended family!
RISK OF ELECTRIC SHOCK
DO NOT OPEN
CAUTION
CAUTION: TO REDUCE THE RISK OF ELECTRIC SHOCK.
DO NOT REMOVE COVER (OR BACK).
NO USER-SERVICEABLE PARTS INSIDE.
REFER SERVICING TO QUALIFIED SERVICE PERSONNEL.
WARNING
To prevent fire or shock hazard, do not
expose the unit to rain or moisture.
*Do not install this equipment in a confined space such as a book case or similar unit.
*The apparatus shall not be exposed to dripping or splashing and no objects filled with liquids, such vases, shall be placed on the apparatus.
*Worded: “WARNING FOR YOUR PROTECTION PLEASE READ THE FOLLOWING-WATER AND MOISTURE: Unit should not be used
near water(e.g. near a bathtub, washbowl, kitchen sink, laundry tub, in a wet basement, or near a swimming pool, etc). Care should be taken
so than objects do not fall and liquids are not spilled into the enclosure through openings.”
This symbol is intended to alert the user to the
presence of uninsulated “dangerous voltage” within
the product’s enclosure that may be of sufficient
magnitude to constitute a risk of electric shock to
persons.
This symbol is intended to alert the user to the
presence of important operation and maintenance
(servicing) instructions in the literature accompanying
the appliance.
Caution: To prevent electric shock do not use this (polarized) plug with
an extension cord, receptacle or other outlet unless the blades
can be fully inserted to prevent blade exposure.
Attentions: Pour prévenir les chocs électriques ne pas utiliser cette
fiche polarisée avec un prolongateur, une prise de courant
on une autre sortie de courant, sauf si les lames peuvent
étre insérées à fond sans en laisser aucune partie à
découvert.

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Installation
Installation
Environment
Never place this product in an environment which could alter its performance or reduce its service life. Such
environments usually include high levels of heat, dust, moisture, and vibration.
Important Safety Instructions
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 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 a third grounding prong. The wide
blade or the third prong are provided for your safety. If the provided plug does not fit into your outlet, consult
an electrician 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 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.
S3125A
S3125A
Unpacking
Although your PA-9312/9324/9336/9348 is neither complicated nor difficult to operate, we recommend you
take a few minutes to read this brief manual and familiarize yourself with the important information regarding
product features, setup and operation.
As with most electronic devices, we strongly recommend you retain the original packaging. In the unlikely event
the product must be returned for servicing, the original packaging (or reasonable equivalent) is required.

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Features
Features
- HIGH POWER, LOW DISTORTION
- 120W (PA-9312), 240W (PA-9324) or 360W (PA-9336) of RMS power, with less than 1% THD.
- 480W(PA-9348) of RMS power, with less than 5% THD.
- BALANCED INPUT
Balanced XLR inputs to reduce ground hum and increase efficiency.
- GAIN ADJUSTMENT
Input gain is adjustable from –12dB to 0dB (1V) via rear panel control.
- EMERGENCY BATTERY BACKUP
Emergency battery backup for unexpected AC power failure.
- SLIM DESIGN, COMPACT SIZE
Streamlined design fits in a compact 3RU space.
Accessories
One detachable AC power cord and XLR cord are provided for use with this product.
Operation
Operation
Make certain that speakers and input sources are properly connected before switching on.
Keep volume levels turned down before switching on.
NOTE: The system’s operation is delayed by approximately three seconds after pressing the power switch. This
is due to the built-in protection circuitry, designed to protect speakers and other system components.

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Front Panel
Front Panel
1. FAN VENTS
These vents provide cool air flow into the unit. It is important to keep them free of obstructions, to prevent the
unit from overheating. It is also important to operate the unit in a dust-free environment.
2. PROTECTION INDICATOR
This LED indicates the state of the amplifier’s protection circuitry. When the Protection LED is on (illuminated),
the protection circuitry is active, indicating that the unit is not operating normally. This is typically due to
overheating or power limiting. Please check the Input and Output condition of the amplifier.
3. POWER LED
When the unit is powered on, the Power LED will glow steadily.
4. OUTPUT LEVEL INDICATOR
These three LEDs indicate the amplifier’s output status. The –40dB LED indicates the presence of audio signal
at the amplifier’s output. The –10dB LED indicates output at nominal operating range. The red CLIP LED
indicates an excessive output level. Do not operate the unit with the CLIP LED continuously on (illuminated).
5. POWER SWITCH
Pressing this switch turns the unit on, as indicated by the Power LED. Pressing it again turns the unit off.
PA
9348
PUBLIC ADDRESS POWER AMPLIFIER
10dB
CLIP
40dB
PROT
OUTPUT & PROTECTION
POWER
OFF
ON
12 3
45

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Rear Panel
Rear Panel
1. SPEAKER OUTPUT TERMINALS
These terminals are used to connect speakers to the unit. You may select either 4Ωor 8Ωconventional
operation, or High Impedance operation at either 70V or 100V. Make certain the combined impedance of
the speakers is equal to or higher than the rated output impedance of the amplifier.
The impedance and output voltage are as follows.
2. LEVEL CONTROL
This knob provides continuous control of the amplifier’s output level, from –12dB to 0dB (reference input of
0dB at 1V). Turning the knob clockwise increases the level, and turning it counter-clockwise decreases the level.
Countries USA/CANADA & Associated Version EC & Associated, JAPAN Version
Output 4Ω8Ω25V 70V 4Ω70V 100V
Terminals
PA-9312 22V - 5.2Ω42Ω22V 42Ω83Ω
PA-9324 31V - 2.6Ω21Ω31V 21Ω42Ω
PA-9336 38V 54V -13.6Ω38V 13.6Ω27.8Ω
PA-9348 43.8V 62V - 10.2Ω43.8V 10.2Ω20.8Ω

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3. FAN VENTS
These vents provide hot air flow out of the unit. It is important to keep them free of obstructions, to prevent the
unit from overheating. It is also important to operate the unit in a dust-free environment.
4. AC POWER INPUT
Connect the supplied standard AC input cable here.
5. FUSE HOLDER
This holder contains the AC overload protection fuse. If the fuse has blown out, replace it with a fuse of the
same type and rating.
If the fuse continues to blow, refer servicing to a qualified service technician.
6. HIGH-PASS FILTER SWITCH
This switch activates the high-pass filter circuitry, which decreases frequencies lower than 400Hz by –3dB.
The high-pass filter is designed to protect speakers from damage caused by excessive low frequency
transients.
7. AUDIO INPUTS
These balanced XLR jacks are for the input of audio signal.
8. GROUND LIFT SWITCH
This switch provides for connection or disconnection of the amplifier’s ground to AC “earth” ground, to
prevent noise from ground loops. Under most circumstances, this switch should be set to FRAME position.
9. DC INPUT TERMINALS
These terminals are provided for the connection of backup battery. Connect a 24VDC(100A) battery source
to these terminals. Make certain the red terminal is connected to the battery’s positive (+) side, and the black
terminal to the battery’s negative (-) side.

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Connecting Speakers
Connecting Speakers
Before connecting speakers to your PA-9312/9324/9336/9348 unit, be sure to disconnect the AC power
cable. Make certain that the total impedance is not less than the rated impedance indicated.
For 4Ωspeakers, connect the positive (+) connector to the 4Ωterminal and the negative (-) connectors to the
COM terminal.
For high-voltage distributed systems, connect with matching transformer to the COM and either B or A
terminals. Be certain that the total impedance does not equal less than the rated impedance.
*The impedance and output voltage are as follows.
Countries USA/CANADA & Associated Version EC & Associated, JAPAN Version
Impedance Low High (B) High (A) Low High (B) High (A)
Output 4Ω8Ω25V 70V 4Ω70V 100V
Terminals
PA-9312 22V - 5.2Ω42Ω22V 42Ω83Ω
PA-9324 31V - 2.6Ω21Ω31V 21Ω42Ω
PA-9336 38V 54V -13.6Ω38V 13.6Ω27.8Ω
PA-9348 43.8V 62V - 10.2Ω43.8V 10.2Ω20.8Ω

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Applications
Applications
* When using connected to a power outlet of
PD-9359, the only one (PA-9348) must
connect the plug to the separate outlet block.

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Block Diagram
Block Diagram
- PA-9312/9324

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Block Diagram
Block Diagram
- PA-9336/9348

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Specifications
Specifications
PA-9312 PA-9324 PA-9336 PA-9348
Rated Output Power (THD 5%, 1kHz) 120W 240W 360W 480W
Frequency Response (+1/-3dB) 70Hz-18kHz
T.H.D Less than 1% Less than 5%
High Pass Filter (400Hz) -3dB
Gain Control -12dB
S/N Better than 95dB Better than 90dB
Input Sensitivity/Impedance 1V/10kΩBalanced
Output Voltage/Impedance 4Ω/22V 4Ω/31V 4Ω/38V 4Ω/43.8V
5.2Ω/25V 2.6Ω/25V 8Ω/54V 8Ω/62V
42Ω/70V 21Ω/70V 13.6Ω/70V 10.2Ω/70V
83Ω/100V 42Ω/100V 27.8Ω/100V 20.8Ω/100V
Operating Temperature -10 C ~ +40 C
Power Source 100–120VAC or 220–240VAC; 50/60Hz, 24VDC
(Supplied AC mains transformer depends on country requirements)
Power Consumption(1/8 power) 130W 310W 380W 600W
Weight 14kg/30.8lb 19kg/41.9lb 21kg/46.3lb 22kg/48lb
Dimensions 482(W) 132(H) 280(D)mm/19(W)x5.2(H)x11(D)in
* Specifications and design subject to change without notice.

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Service
Service
Procedures
Take steps to insure the problem is not related to operator error or other products within the system. Information
provided in the troubleshooting portion of this manual may help with this process. Once it is certain that the
problem is related to the product contact your warranty provider as described in the warranty section of this
manual.
Schematic
A Schematic is available by contacting your warranty provider.
Parts List
A Parts List is available by contacting your warranty provider.
Variations and Options
Variations and Options
Variations
Products supplied through legitimate sources are compatible with local AC power requirements.
Options
No optional items are available for this product.
Warranty
Warranty
Warranty terms and conditions vary by country and may not be the same for all products. Terms and conditions
of warranty for a given product may be determined first by locating the appropriate country which the product
was purchased in, then by locating the product type.
To obtain specific warranty information and available service locations contact Inter-M directly or the authorized
Inter-M Distributor for your specific country or region.

MADE IN KOREA
April 2006 9000000420
Inter-M, Ltd. (Korea) began operations in 1983.
Since then, Inter-M has grown to become one of the largest manufacturers
of professional audio and commercial sound electronics equipment in the world.
Inter-M has gained worldwide recognition for its own branded products,
as well as private label manufacturing of electronics sold under other names (OEM).
The company is no longer just a Korean company, but rather a global company
that is truly international in scope, with factories and offices in Korea and China,
and sales and marketing operations located in Japan, Europe, and the U.S.A.
With more than 850 employees around the globe,
Inter-M is well-poised for further growth and expansion.
INTER-M AMERICAS, INC.
1 EAST BEACON LIGHT LANE CHESTER, PA USA 19013-4409
TEL : [phone], FAX : [phone]
Home Page : http://www.inter-m.net, E-mail : [email protected]
INTER-M Corporation
SEOUL OFFICE:653-5 BANGHAK-DONG, DOBONG-KU, SEOUL, KOREA
TEL : [phone]~8, FAX : [phone]
Home Page : http://www.inter-m.com, E-mail : [email protected]