Studiomaster Professional PA Series User manual

PA SERIES
DUAL CHANNEL
POWER AMPLIFIERS
Owner’s Manual
Models: PA 1.5, PA 2.0, PA 3.0, PA 4.5, PA 6.0, PA 7.5, PA 10.0

The lightning flash with arrowhead symbol
within an equilateral triangle 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.
The exclamation point within an equilateral
triangle is intended to alert the user to the pre-
sence of important operating and maintenance
(servicing) instructions in the literature
accompanying the product.
Explanation of Graphical Symbols
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.
Tips for Safe Operation
IMPORTANT SAFETY INSTRUCTIONS
RISK OF ELECTRIC SHOCK
DO NOT OPEN
CAUTION
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 Protect the power cord from being walked on or
pinched particularly at plugs, convenience
receptacles, and the point where they exit from the
apparatus.
10 Only use attachments/accessories specified by the
manufacturer.
11 Use only with the cart, stand,
tripod, bracket, or table spec-
ified by the manufacturer, or
sold with the apparatus.
When a cart is used, use cau-
tion when moving the cart/
apparatus combination to
avoid injury from tip-over.
WARNING
TO REDUCE THE RISK OF FIRE OR ELECTRIC SHOCK,
DO NOT EXPOSE THIS APPARATUS TO RAIN OR MOISTURE.
IMPORTANT NOTICE
Connecting the Plug and Cord
WARNING: THIS APPARATUS MUST BE EARTHED
IMPORTANT. The wires in this mains lead are coloured in accordance
with the following code:
GREEN-AND-YELLOW: EARTH
BLUE: NEUTRAL
BROWN: LIVE
As the colours of the wires in the mains lead of this apparatus may not
correspond with the coloured markings identifying the terminals in
your plug proceed as follows:
The wire which is coloured GREEN-and-YELLOW must be connected
to the terminal in the plug which is marked by the letter E or by the
safety earth symbol or colored GREEN or GREEN-and-YELLOW.
The wire which is coloured BLUE must be connected to the terminal
which is marked with the letter N or coloured BLACK.
The wire which is coloured BROWN must be connected to the terminal
which is marked with the letter L or coloured RED.
12 Unplug this apparatus during lightning storms or when
unused for long periods of time.
13 Refer all servicing to qualified service personnel.
Servicing 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.
The 3 core AC mains cable should be terminated with this
AC mains plug by connecting brown/red wire on live pin
(L), black wire on neutral pin (N) and yellow/green wire
on earth pin (E).
Do not operate the amplifier with continuously blinking
CLIP LED. The respective volume control of the channels
must be adjusted so that the output level does not clip and
distort. Do not obstruct the front or back of the amplifier
for necessary intake of air.
The amplifier must be connected to an AC earthed mains
oultet that can delivered the maximum power required.
The use of extension cables or adaptors should be avoided
as this can jeoparadize correct delivery to the amplifier.
All connections must only be carried out or changed with
the amplifier switched OFF. Ensure proper impedance
matching while in use for BRIDGE mode applications.
For continous safe operation, resultant impedance of the
speakers 8 ohm/4 ohm is recommended.
For 2 ohm/4 ohm applications, it is recommended to use
speakon connectors only. Use of cable 40/36 or thicker is
recommended to prevent power losses.
The level of input signal should not exceed the specified
input sensitivities. Excessive input signal level result in
over driving of input circuit which leads to saturated /
distorted output at speaker terminals.
2

Precautions
For safe operation
WARNING
CAUTION
Installation
Operation
In case an abnormality occurs during operation
Operation
Installation
Connect this unit’s power cord only to an AC outlet of the type
stated in this Owner’s Manual or as marked on the unit. Failure
to do so is a re and electrical shock hazard.
Do not allow water to enter this unit or allow the unit to become
wet. Fire or electrical shock may result.
Do not place a container with liquid or small metal objects on
top of this unit. Liquid or metal objects inside this unit are a re
and electrical shock hazard.
Do not place heavy objects, including this unit, on top of the
power cord. A damaged power cord is a re and electrical shock
hazard. In particular, be careful not to place heavy objects on a
power cord covered by a carpet.
Do not scratch, bend, twist, pull, or heat the power cord. A dam-
aged power cord is a re and electrical shock hazard.
Do not remove the unit’s cover. You could receive an electrical
shock. If you think internal inspection, maintenance, or repair is
necessary, contact your dealer.
Do not modify the unit. Doing so is a re and electrical shock
hazard.
If lightning begins to occur, turn off the power switch of the unit
as soon as possible, and unplug the power cable from the electrical
outlet.
If there is a possibility of lightning, do not touch the power cable
plug if it is still connected. Doing so may be an electrical shock
hazard.
If the power cord is damaged (i.e., cut or a bare wire is exposed),
ask your dealer for a replacement. Using the unit with a damaged
power cord is a re and electrical shock hazard.
Should this unit be dropped or the cabinet be damaged, turn the
power switch off, remove the power plug from the AC outlet, and
contact your dealer. If you continue using the unit without heed-
ing this instruction, re or electrical shock may result.
If you notice any abnormality, such as smoke, odor, or noise, or
if a foreign object or liquid gets inside the unit, turn it off imme-
diately. Remove the power cord from the AC outlet. Consult your
dealer for repair. Using the unit in this condition is a re and
electrical shock hazard.
Keep this unit away from the following locations:
- Locations exposed to oil splashes or steam, such as near cook-
ing stoves, humidiers, etc.
- Unstable surfaces, such as a wobbly table or slope.
- Locations exposed to excessive heat, such as inside a car with
all the windows closed, or places that receive direct sunlight.
- Locations subject to excessive humidity or dust accumulation.
Do not place the power cord close to a heater. It may melt, caus-
ing re or electrical shock.
Hold the power cord plug when disconnecting it from an AC out-
let. Never pull the cord. A damaged power cord is a potential re
and electrical shock hazard.
Do not touch the power plug with wet hands. Doing so is a
potential electrical shock hazard.
This unit has ventilation holes at the front, rear & top to prevent
the internal temperature rising too high. Do not block them.
Blocked ventilation holes are a re hazard.
In particular, do not
- place the unit on its side or upside down,
- place the unit in any poorly-ventilated location such as a
bookcase or closet (other than on the dedicated rack),
- cover the unit with a table cloth or place it on a carpet or bed.
Allow enough free space around the unit for normal ventilation.
This should be: 5 cm at the sides, 10 cm behind, and 10 cm
above.
If the airow is not adequate, the unit will heat up inside and
may cause a re.
To mount several of these units in a standard EIA rack, refer to
the rack mounting instructions on page 16.
To relocate the unit, turn the power switch off, remove the power
plug from the AC outlet, and remove all connecting cables. Dam-
aged cables may cause re or electrical shock.
Use only thick speaker cables when connecting speakers to amp-
lifier outputs. Use of cables type 40/36 or thicker is recommended
for connecting low impedance speakers to avoid power loss in the
cables, as heavy current flows through the cables. Using other
types of cables is a fire hazard.
Turn off all musical instruments, audio equipment, and speakers
when connecting to this unit. Use the correct connecting cables
and connect as specied.
Always lower the volume control to minimum before turning on
the power to this unit. A sudden blast of sound may damage your
hearing.
Do not use this amplier for any purpose other than driving loud-
Be sure of proper impedance of 2/4/8 ohm when used for
STEREO/PARALLEL configuration & 4/8 ohm recommended
when used in BRIDGE mode.
speakers.
If you know you will not use this unit for a long period of time,
When operating amplifier on a generator, make sure it is switched
“OFF” till generator voltages has stabilized & then only switch
“ON” amplifier.
such as when going on vacation, remove the power plug from the
AC outlet. Leaving it connected is a potential re hazard.
3

Thank you for your purchase of the STUDIOMASTER PA Series power amplifiers. These amplifiers fully incorporate
STUDIOMASTER’s renowned technology and offers high reliability, rock solid stability and superb acoustic characteristics.
Features / General Description of Product
This owners Manual covers 6 models PA 1.5, PA 2.0, PA 3.0, PA 4.5, PA 6.0, PA 7.5 & , PA 10.0 power amplifiers.
Please read through this manual carefully before beginning use, so that you will be able to take full advantage of amplifier’s
superlative features & enjoy trouble free operation for years to come. After reading through the manual, please store it in a
safe place.
Rugged 19” rack mountable design of chassis.
High current torroidal transformer which provides excellent regulation and minimized hum & noise.
Low THD and high damping factor for excellent sound quality.
Extensive protection circuitry for Temperature ( transistor and transformer ), Overload, Over voltage, DC, RFI & Output
short circuit. The amplifier is fully protected for variations in AC supply due to Genset Mains fluctuation.
Indicator LEDs for Signal, Clip, Temperature (output devices and transformer), Fault & Overload conditions.
Output termination on 4 way speakon Connectors for each channels.
Limiter circuit protects the amplifier and speaker from being over driven because of high input level signal.
Balanced / Unbalanced input signal through parallel XLR and 6.3mm (1/4”) stereo phone jack in both channels.
Slide switch selection of Mono / Stereo / Bridge Mode provided at rear panel.
5

Features / General Description of Product........................................................5
Front Panel Controls & Features......................................................................6
Rear Panel Controls & Features.......................................................................7
Input-Output Connections................................................................................8
Setup & Operations..........................................................................................9
Typical Applications.......................................................................................12
Protections & Installations.............................................................................16
Trouble Shooting............................................................................................17
Block Diagram...............................................................................................19
Specifications.................................................................................................22
Note................................................................................................................23
4
Contents Page No.

Front Panel Controls & Features
1 Master switch
Switches the unit on and off, interrupting both phases.
2 Power ON indicator light
When lit, this green LED indicates correct operation of the channel
3 Volume control.
Used for adjusting the volume of the channel.
4 Signal indicator
Green LED that indicates the presence of the signal in the final stage. It lights up with signals higher than - 20dB.
5 Limiter-peak indicator
This red LED lights up to indicates that the internal limiter has been activated to eliminate clip. When the limiter is activated,
it indicates that the maximum amplification has been reached. When it lights up continuously, this means there is an
excessive signal input.
6 Mute indicator
Yellow LED that indicates the mute status of the channel and is lit for the following reasons: switch on delay (3 seconds),
presence of continuous voltage on the channel output, short circuit, thermal protection of the channel, thermal protection of
the transformer.
7 Thermal protection indicator
Red LED that lights up to indicate an excessive temperature. When this protection is tripped, the amplifier remains in mute
status until a normal operating temperature has been restored. It indicates overheating of both the channels and the
transformer, in which case the indicators of both channels will be lit.
6
Rear Panel Controls & Features
1 Balanced 6.3 mm jack input
This stereo jack connector takes the signal (balanced/unbalanced) for driving the channel. If the signal is unbalanced, a mono
connector may be used.
2 Balanced XLR input
This XLR connector takes the signal (balanced/unbalanced) for driving the channel. If the signal is unbalanced, pin 2 can be
used for the signal and pin 3 connected to the earth.
3 CH 1 output speakon connector
Use this connector for picking up the amplified signal of CH 1 and signal for bridged configuration.
4 CH 2 output speakon connector
Use this connector for picking up the amplified signal of CH 2.
5 Power cable
Use this cable for supplying power to unit.

6 Configuration switch
This three way switch configures the amplifier for the three working modes: mono, stereo and bridge.
7 Air intake grill
The air for cooling the amplifier is taken in from this grill. Do not obstruct the grill, & clean the air filter whenever necessary.
8 Sensitivity
This switch is used to select sensitivity to either 0.775V or 1.2V depending on the source.
9 Limiter
This switch activates limiter when in ON position. The limiter prevents distortion of the output level when its gets overloaded.
When the output level exceeds its maximum, an internal adjustment will be made to prevent overloading. The limiter is
specially designed to safeguard connected full-range speakers. The high tone piezo drivers of these speakers are now protected
against distortion and harmonic signals which are the result of over steering the amplifier. When the amplifier is used as a
subwoofer amplifier then the limiter has to be switched off to set the extra “punch”.
7
13
SENSITIVITY
1.2V OFF ON
0.775V
LIMITER LOW-CUT
OFF ON
CH1/
BRIDGE
OUT
CH2
OUT
FOR MONO OR BRIDGE MODE USE INPUT CH1.
WARRANTY VOIDS IF
SERIAL NO. IS MISSING
Output Connections
Stereo Mode
+1 = speaker +
-1 = speaker -
Mono Mode
Bridged Mode
CH1 only
+2 = speaker +
-2 = speaker -
MADE IN INDIA
13
PA 3.0
1.2V OFF OFF ONON STEREOMONO BRIDGE
0.775V
LIMITER LOW-CUT MODE
SENSITIVITY
FOR MONO OR BRIDGE MODE USE INPUT CH1.
V1
Output Connections
Stereo Mode
+1 = speaker +
-1 = speaker -
Mono Mode
Bridged Mode
CH1 only
+2 = speaker +
-2 = speaker -
CH 2
OUT
CH1/BRIDGE
OUT
MADE IN INDIA
11 1213
LIMITER
LOW-CUTHF PROTECT
SENSITIVITY
0.775V 1.2V OFF ON
OFF ON OFF ON GROUND LIFT
MONO
STEREO
BRIDGE
240V ~/50Hz, 20A
Output Connections
Stereo Mode
+1 = speaker +
-1 = speaker -
Mono Mode
Bridged Mode
CH1 only
+2 = speaker +
-2 = speaker -
CH 2 OUT
CH1/BRIDGE
OUT
For MONO or BRIDGE MODE
use Input CH1.
MADE IN INDIA
LIMITER
LOW-CUTHF PROTECT
SENSITIVITY
0.775V 1.2V OFF ON
OFF ON OFF ON GROUND LIFT
MONO
STEREO
BRIDGE
240V ~ 50Hz
For MONO or BRIDGE MODE
use Input CH1.
MADE IN INDIA
WARRANTY VOIDS IF
SERIAL NO. IS MISSING
*[e-mail]
91-8879028079
[phone] / 001
CH 2 OUT
CH1/BRIDGE
OUT
MCB
PUSH TO RESET
Output Connections
Stereo Mode
+1 = speaker +
-1 = speaker -
Mono Mode
Bridged Mode
CH1 only
+2 = speaker +
-2 = speaker -
11 1213 14
PA 4.6, PA 6.0, PA 10.0.
PA 7.5
PA 1.5, PA 2.0.

10 Low-cut
Low-cut switch filters the low frequencies from the input signal. Cut off frequency is 20 Hz when it is selected. The filter
protects the cone of the speakers against unwanted and inaudible low frequencies.
11 Ground/Lift switch
Allows input connector & chassis/circuit ground to be separated to address problem with earth loop.
12 HF Protection switch
It is a protection for the amplifier against HF. In case there is high amplitude HF signal at the output, it drops the power of the
amplifier thus protecting the internal circuitry.
Presence of prolonged, large amplitude, high frequency output can damage the speakers as well as the internal circuit of the
amplifier. The HF Protection circuit continuously monitors the output and drops the amplifier power, if the high frequency
persists for more than 10-15 seconds. The HF Protection has no effect on normal music.
13 External earth terminal
For a possible ground connection (e.g. in case of hum problems).
14 circuit breaker (MCP)
The circuit breaker is provided to avoid amplifier failure caused due to a sudden surge or continuous high current supply
Input-Output Connections
8

SENSITIVITY
1.2V OFF ON
0.775V
LIMITER
PA 2.0
LOW-CUT
OFF ON
CH1/
BRIDGE
OUT
V1
CH2
OUT
FOR MONO OR BRIDGE MODE USE INPUT CH1.
WARRANTY VOIDS IF
SERIAL NO. IS MISSING
Output Connections
Stereo Mode
+1 = speaker +
-1 = speaker -
Mono Mode
Bridged Mode
CH1 only
+2 = speaker +
-2 = speaker -
MADE IN INDIA
Setup & Operation
Stereo Mode Configuration
In STEREO mode, both channels 1 & 2 are fully independent of each other. The balanced /unbalanced inputs can be connected
either to a stereo signal source or two independent mono signal sources. Each channel can separately drive loudspeaker loads of
8 ohm or 4 ohm or 2 ohm.
Connect the Left & Right outputs of a mixer to channel 1
& 2 inputs of the amplifier respectively. Inputs can be
wired as per fig.1 & 2 (Input Connections for Balanced &
Unbalanced Mode)
Connect a speaker system (8 ohm / 4 ohm / 2 ohm) on the
output terminal of each channel. It is recommended to use
the speakon connectors and wire these as per fig.3 (Output
Connections for Stereo / Mono Mode)
To select STEREO mode, keep the slide switch,
provided at rear panel, in STEREO position.
Adjust the individual volume controls of each channel
on the front panel to obtain the desired output level.
The level indicator LEDs glow to indicate the presence
of signal at the output terminals.
9
PA MIXER
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AQ UA 10

Setup & Operation
When operating in MONO mode, the signal source should be connected to the balanced / unbalanced inputs of channel 1 only.
Both channels provide similar outputs to their respective loudspeakers. Each channel can separately drive loudspeaker loads of
8 ohm or 4 ohm or 2 ohm.
Connect the line output of a mixer to a channel input of
the amplifier. Inputs can be wired as per fig.1 & 2 (Input
Connections for Balanced and Unbalanced Mode)
Connect a speaker system (8 ohm / 4 ohm / 2 ohm) on the
output terminal of each channel. It is recommended to
use the speakon connectors and wire these as per fig.3
(Output Connections for Stereo / Mono Mode)
To select MONO mode, keep the slide switch, provided at
rear panel, in mono position.
The desired output levels of both the channels are adjustable
by volume control of both the channels individually.
The level indicator LEDs glow to indicate the presence of
signal at the output terminals.
10
Mono Mode Configuration
SENSITIVITY
1.2V OFF ON
0.775V
LIMITER
PA 2.0
LOW-CUT
OFF ON
CH1/
BRIDGE
OUT
V1
CH2
OUT
FOR MONO OR BRIDGE MODE USE INPUT CH1.
WARRANTY VOIDS IF
SERIAL NO. IS MISSING
Output Connections
Stereo Mode
+1 = speaker +
-1 = speaker -
Mono Mode
Bridged Mode
CH1 only
+2 = speaker +
-2 = speaker -
MADE IN INDIA
PA MIXER
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AQ UA 10

Setup & Operation
For BRIDGE mode operation, the signal source should be connected to the balanced /unbalanced inputs of channel 1 only. This
mode combines power output of both channels for connecting a single loudspeaker load. The combined loudspeaker load should
not go to below 4 ohm.
Connect the line output of a mixer to a channel 1 input of
the amplifier. Input can be wired as per fig.1 & 2 (Input
Connections for Balanced and Unbalanced Mode)
Connect a speaker system (8 ohm / 4 ohm) on the speakon
output of channel 1 only. It is recommended to use the
speakon connectors and wire these as per fig.4 (Output
Connections for Bridge Mode)
To select BRIDGE mode, keep the slide switch, provided at
rear panel, in Bridge position.
The desired output levels of both the channels are adjustable
by volume control of channel 1 only.
The level indicator LEDs glow to indicate the presence of
signal at the output terminals.
11
Bridge Mode Configuration
SENSITIVITY
1.2V OFF ON
0.775V
LIMITER
PA 2.0
LOW-CUT
OFF ON
CH1/
BRIDGE
OUT
V1
CH2
OUT
FOR MONO OR BRIDGE MODE USE INPUT CH1.
WARRANTY VOIDS IF
SERIAL NO. IS MISSING
Output Connections
Stereo Mode
+1 = speaker +
-1 = speaker -
Mono Mode
Bridged Mode
CH1 only
+2 = speaker +
-2 = speaker -
MADE IN INDIA
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1 2 345678910
AQ UA 10
PA MIXER

Typical Applications
Connect the left & Right outputs of the Audio mixing
console to the respective inputs of the Active Crossover.
Connect the Left & Right High frequency output of the
active crossover to the respective input channels 1 & 2
of amplifier 1. Inputs can be wired as per fig. 1 & 2
(Input Connections for Balanced & Unbalanced Mode)
One no. of full range loudspeaker system can be
connected to each of the channels of amplifier 1. The
output speakon connectors should be wired as per fig. 3
(Output Connections for Stereo/Mono Mode) Amplifier
1 will be used in stereo mode. Keep the slides switch of
amplifier 1 in stereo position.
Feed the Sub output signal of the crossover to channel 1
input of amplifier 2. Input can be wired as per fig. 1 & 2
(Input Connections for Balanced & Unbalanced Mode)
One no. of each of high powered subwoofer system can
be connected to the channel 1 output of amplifier 2.
Output speakon connectors can be wired as per fig. 4
(Output Connections for Bridge Mode).
Amplifier 2 will be used in bridge mode. Keep the slide
switch of amplifier 2 to BRIDGE position to activate
bridge mode.
Finally adjust the volume control of channel 1 & 2 in
amplifier 1 to control the level of their respective position
to get desired power. Also, adjust the volume control of
channel 1 in amplifier 2 to control the levels of Sub out.
12
SENSITIVITY
1.2V OFF ON
0.775V
LIMITER
PA 2.0
LOW-CUT
OFF ON
CH1/
BRIDGE
OUT
V1
CH2
OUT
FOR MONO OR BRIDGE MODE USE INPUT CH1.
WARRANTY VOIDS IF
SERIAL NO. IS MISSING
Output Connections
Stereo Mode
+1 = speaker +
-1 = speaker -
Mono Mode
Bridged Mode
CH1 only
+2 = speaker +
-2 = speaker -
MADE IN INDIA
SENSITIVITY
1.2V OFF ON
0.775V
LIMITER
PA 2.0
LOW-CUT
OFF ON
CH1/
BRIDGE
OUT
V1
CH2
OUT
FOR MONO OR BRIDGE MODE USE INPUT CH1.
WARRANTY VOIDS IF
SERIAL NO. IS MISSING
Output Connections
Stereo Mode
+1 = speaker +
-1 = speaker -
Mono Mode
Bridged Mode
CH1 only
+2 = speaker +
-2 = speaker -
MADE IN INDIA
Stereo Mix Plus Subwoofer
PA MIXER
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1 2 345678910
AQ UA 10

Typical Applications
Connect the left and Right outputs of the Audio mixing
console to the channel 1 & 2 (XLR/jack) of amplifier 1.
The XLR and jack inputs of the amplifier are in parallel.
Either ones can be used.
Connect CH 1 jack input of amplifier 1 to CH 1 XLR/jack
of amplifier 2. Similarly connect for CH 2. Speakers can
be connected to respective output but ensure that resultant
impedance is not less than 2 ohms. The input can be wired
as per fig. 1 & 2 (Input Connections for Balanced and
Unbalanced Mode)
The speaker connections of amplifier 2 are done in a similar
way as for amplifier 1.
Amplifier 1 & 2 will be used in stereo mode. Keep the slide
switch of amplifier 1 & 2 in stereo position.
Adjust the volume controls of channel 1 & 2 of both the
amplifiers to control the levels of their respective Speakers.
Finally any adjustments in the total quantity of the sound,
if required, can be made from the audio mixing console.
13
SENSITIVITY
1.2V OFF ON
0.775V
LIMITER
PA 2.0
LOW-CUT
OFF ON
CH1/
BRIDGE
OUT
V1
CH2
OUT
FOR MONO OR BRIDGE MODE USE INPUT CH1.
WARRANTY VOIDS IF
SERIAL NO. IS MISSING
Output Connections
Stereo Mode
+1 = speaker +
-1 = speaker -
Mono Mode
Bridged Mode
CH1 only
+2 = speaker +
-2 = speaker -
MADE IN INDIA
Stereo Mode - Cascade Configuration
SENSITIVITY
1.2V OFF ON
0.775V
LIMITER
PA 2.0
LOW-CUT
OFF ON
CH1/
BRIDGE
OUT
V1
CH2
OUT
FOR MONO OR BRIDGE MODE USE INPUT CH1.
WARRANTY VOIDS IF
SERIAL NO. IS MISSING
Output Connections
Stereo Mode
+1 = speaker +
-1 = speaker -
Mono Mode
Bridged Mode
CH1 only
+2 = speaker +
-2 = speaker -
MADE IN INDIA
PA MIXER
1 2 345678910
1 2 345678910
AQ UA 10

Typical Applications
Connect the left line output of the Audio mixing console
to the channel 1 input (XLR/jack) of amplifier 1. The XLR
& jack inputs of the amplifier are in parallel and either ones
can be used.
Connect the unused channel 1 input ( jack/XLR) of
amplifier 1 to the channel 1 input (XLR/jack) of amplifier 2.
The jack & XLR inputs can be wired as per fig. 1 & 2 (Input
Connections for Balanced and Unbalanced Mode).
The Left speaker stack compromises of four nos. speaker
systems. Each speaker is individually connected to the four
speaker outputs available from amplifier 1 (channel 1 & 2)
& amplifier 2 (channel 1 & 2). Output speakon connectors
to be wired as per fig. 3 (Output Connections for Stereo/
Mono Mode). Amplifier 1 & 2 will be used in mono mode.
Keep the slide switch of amplifier 1 & 2 in mono position.
Similarly, connect the Right line output of the Audio mixing
console to the channel 1 input (XLR/jack) of amplifier 3.
Also connect the unused channel 1 input (jack/XLR) of
amplifier 3 to the channel 1 input (XLR/jack) of amplifier 4.
The Right speaker stack’s connections are done in a similar
way as for left speaker stack’s connections. Amplifier 3 & 4
will also be used in mono mode. Adjust the volume controls
of individual channels of four amplifier to control the levels
of their respective speakers. Finally any adjustments in the
total quality of the sound, if required, can be made from the
audio mixing console.
14
SENSITIVITY
1.2V OFF ON
0.775V
LIMITER
PA 2.0
LOW-CUT
OFF ON
CH1/
BRIDGE
OUT
V1
CH2
OUT
FOR MONO OR BRIDGE MODE USE INPUT CH1.
WARRANTY VOIDS IF
SERIAL NO. IS MISSING
Output Connections
Stereo Mode
+1 = speaker +
-1 = speaker -
Mono Mode
Bridged Mode
CH1 only
+2 = speaker +
-2 = speaker -
SENSITIVITY
1.2V OFF ON
0.775V
LIMITER
PA 2.0
LOW-CUT
OFF ON
CH1/
BRIDGE
OUT
V1
CH2
OUT
FOR MONO OR BRIDGE MODE USE INPUT CH1.
WARRANTY VOIDS IF
SERIAL NO. IS MISSING
Output Connections
Stereo Mode
+1 = speaker +
-1 = speaker -
Mono Mode
Bridged Mode
CH1 only
+2 = speaker +
-2 = speaker -
SENSITIVITY
1.2V OFF ON
0.775V
LIMITER
PA 2.0
LOW-CUT
OFF ON
CH1/
BRIDGE
OUT
V1
CH2
OUT
FOR MONO OR BRIDGE MODE USE INPUT CH1.
WARRANTY VOIDS IF
SERIAL NO. IS MISSING
Output Connections
Stereo Mode
+1 = speaker +
-1 = speaker -
Mono Mode
Bridged Mode
CH1 only
+2 = speaker +
-2 = speaker -
MADE IN INDIA
Mono Mode - High Power Dual Channel Configuration
PA MIXER
SENSITIVITY
1.2V OFF ON
0.775V
LIMITER
PA 2.0
LOW-CUT
OFF ON
CH1/
BRIDGE
OUT
V1
CH2
OUT
FOR MONO OR BRIDGE MODE USE INPUT CH1.
WARRANTY VOIDS IF
SERIAL NO. IS MISSING
Output Connections
Stereo Mode
+1 = speaker +
-1 = speaker -
Mono Mode
Bridged Mode
CH1 only
+2 = speaker +
-2 = speaker -
MADE IN INDIA
1 2 345678910
1 2 345678910
AQ UA 10

100V Operation For PA Application (Only PA 1.5 & PA 2.0)
15
SENSITIVITY
1.2V OFF ON
0.775V
LIMITER LOW-CUT
OFF ON
CH1/
BRIDGE
OUT
CH2
OUT
FOR MONO OR BRIDGE MODE USE INPUT CH1.
WARRANTY VOIDS IF
SERIAL NO. IS MISSING
Output Connections
Stereo Mode +1 = speaker + -1 = speaker - Mono Mode
Bridged Mode
CH1 only
+2 = speaker + -2 = speaker -
MADE IN INDIA

Protections & Installations
PA 3.0/PA 4.5/PA 6.0/PA 7.5/PA 10.0 Handle Fitting Instruction
Thermal Protection
Due to excessive heating of transformer, the thermal
protection circuit brings the audio signal to mute state.
To restore normal operation conditions, it is
recommended to switch off the amplifier & rectify the
cause.
DC, RFI Protection
Inbuilt circuitry is provided to protect the loudspeaker
from any offset DC voltages. Also sufficient suppression
filters at primary & secondary power supplies have been
inbuilt, to overcome RF interferences.
Overload / Short Circuit Protection
Protection circuit is provided in both channels for the
safety of output devices in case of overloading or
mismatching of impedances at outputs. This circuit brings
the input signals to respective channels are pressed.
DC Fuses
PA 1.5 / PA 2.0
2 x 12A fuses for +ve and -ve DC supply
PA 3.0
2 x 20A fuses for +ve and -ve DC supply.
PA 4.5, PA 6.0
2 x 25A fuses on Power Amp PCB.
PA 7.5, 10.0
2 x 30A fuses on Power Amp PCB.
Due to excessive heating of output devices, the thermal
protection circuit brings the audio signal to mute state
Onset of thermal protection circuit is indicated by
glowing of TEMP LEDs (yellow) in each channel. To
restore normal operation conditions, it is recommended
to switch off the amplifier and rectify the cause.
The amplifier is designed for use in a standard 19” rack
with height of 2U units (PA 1.5 & PA 2.0) and 3U units
(PA 3.0, PA 4.5, PA 6.0 & PA 7.5).
In order to provide sufficient support base to the heavy
amplifier, it is essential to use the 19” rack system with side
support mounting also in addition to front screw mounting
as shown in the figure below.
19” Rack Installation
The ‘U’ handles are helpful in easy portability of the
amplifier for table top usage.
Table Top Usage
Note:- 1) Handles to be fitted on both sides as shown in diagram above.
2) Handle (PVCIPC98) 2 nos. & Screw M5x10 (HRDBN458) 4 nos. are included in packing.
Output Devices
Transformer
Sign Sign
Mute Mute
On On
Lim Lim
Temp Temp
010 010
CH2
CH1
Screw M5x10mm
(HRDBN458) 4 Nos.
(PVCIPC98) 2 Nos.
Handle
16

Trouble Shooting
Key to LED symbols:
1) Indication:
Condition: Normal operation
Possible Reason:
The amplifier is in normal operation
2) Indication:
Condition: No power to the amplifier
Possible Reason:
The amplifier power switch may be off. The amplifier may not be plugged into the power receptacle. Conform that the AC
outlet works by plugging in another device. If too many amplifier are used on one outlet, the building’s circuit breaker may
trip and shut off power. An overload in bridge mode may cause tripping of main switch on front panel. An amplifier which
keeps shutting off may have a serious internal fault. Turn it off, remove AC power cord and get the amplifier serviced by a
qualified technician.
3) Indication:
Condition: Low output
Possible Reason:
Check if the level of the input signal is too low. Check the signal source is operating & the input cable is intact. The channel
volume control setting is not at desired level. Similarly conditions may occur in MONO and BRIDGE mode.
4) Indication:
Condition: No Sound
Possible Reason:
The amplifier goes in mute mode due to excessive input signal, speaker impedance mismatch or output short circuit. Check
the speaker impedance & speaker wiring for stray strands or breaks in the insulation. Reduce the volume control, for desired
output. Similarly conditions are possible in MONO and BRIDGE mode also.
5) Indication:
Condition: No Sound
Possible Reason:
The amplifier goes in mute mode due to output short circuit, overloading or poor ventilation resulting into the rise in
temperature either of output devices or power transformer. Switch off the amplifier to cool down. Check if the fan is working,
proper ventilation is provided & output connections are as recommended. To restore normal operation, turn down the volume
control, press the reset button once and increase the volume control for desired output. Similarly conditions may occur in
MONO & BRIDGE mode.
6) Indication:
Condition: Distorted Sound
Possible Reason:
The input signal level may be too high. So turn down the amplifier level controls. Check the level of source from input
source. If it is high then reduce the input signal level. The amplifier should never be operated at a level which causes the
LIM LEDs to illuminate constantly. Similar conditions may occur in MONO and BRIDGE mode.
7) Indication:
Condition: Either low or no sound
Possible Reason:
This could be due to wrong speakon connections or faulty speaker. Check the output speakon connections as per fig. 4 on
page no. 8 (Output Connections for Bridge Mode)
ON MUTE SIGN LIM TEMP
ON MUTE SIGN LIM TEMP
ON MUTE SIGN LIM TEMP
ON MUTE SIGN LIM TEMP
ON MUTE SIGN LIM TEMP
ON MUTE SIGN LIM TEMP
ON MUTE SIGN LIM TEMP
GLOWING BLINKING OFF
17

8) Condition: Hum
Possible Reason:
Move cabling and signal sources to identify the problems areas in the system. Cables with faulty shielding are a frequent
entry point from hum. In the situation where the hum is present in the installations could be due to close looping of ground, cut
the jumper on the input PCB to isolate input ground to mains earth.
9) Condition: Hiss
Possible Reason:
Unplug the amplifier input to confirm whether the hiss is coming from the source or a device upstream. The erratic or
popping noises indicate an electronic fault in the offending unit.
18

Block Diagram
19

Block Diagram
20
Block Diagram for Model PA 4.5 / 6.0