Opal Audio PLX3.0 User manual

USER'S MANUAL
OPAL AUDIO,Inc
ADD 2254 ROYAL LANE, DALLAS TX 75229, U.S.A
Professional Audio

USER'S MANUAL
The information contained in this manual is subject to change without notice.
No part of this manual may be reproduced or transmitted in any form or by any
means, electronic or mechanical, including photocopying and recording of any kind.
PLX Series
SWITCHING POWER AMPLIFIERS
PLX3.0
PLX4.5
PLX5.5
PLX6.5

OPAL Products
Service Information Form
Owner's Name:
Shipping address:
Street:
City:
Zip Code:
Country:
Phone Number: Fax Number:
Email:
MODEL: SERIAL:
NUMBER:
Place of Purchase:
Name of Dealer:
Full Address:
DATE OF PURCHASE:
Nature of the problem
(Be sure to describe the conditions that existed when the problem occurred and what
attempts were made to correct it.)
Other equipment in your system
If warranty has expired, payment method: Cash Check Visa Master
card number: Signature:
Enclose this form with the defective unit. Do not mail separately.

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WEEE Mark
If you wantto dispose ofthis product, donot mix withgeneral
household waste. Thereare separate collectionsystems for used
electronic products inaccordance with legislationunder the WEEE
Directive (Directive 2002/96/EC)and is effectiveonly within the
European Union.
LIMITED WARRANTY
THE WARRANTY
For a period of One (1) year from the date of delivery to the original purchaser (as shown on the original invoice or sales
receipt), OPAL International Group Limited warrants to the ORIGINAL OWNER of each product (provided it was
purchased at an Authorized OPALDealer) that it is free of defects in materials and workmanship and that each product will
meet or exceed all factory published specifications for each respective model. OPAL agrees to repair or replace (at its
discretion) all defective parts at no charge for labor or materials; subject to following provisions:
WARRANTY VIOLATIONS
OPAL shall take no responsibility for repair or replacement as specified under this warranty, if the damaged product has
been subject to misuse, accident, neglect or failure to comply with normal maintenance procedures; or if the serial
number has been defaced, altered or removed. Nor will OPAL accept responsibility for, or resulting from, improper
alterations or unauthorized parts or repairs. This warranty does not cover any damage to speakers or any other
consequential damage resulting from breach of any written or implied warranty.
OPAL WARRANTYPROVISIONS
OPAL will remedy any defect, regardless of the reason for failure (except as excluded ) by repair, or replacement. OPAL
will remedy the defect and ship the product within a reasonable time after receipt of the defective product at an OPAL
Authorized Service Center.
TO OBTAIN WARRANTYSERVICE
In the event that an OPAL product requires service, the Owner must contact OPAL or an Authorized OPAL Service Center
to receive an R.A.N. ( Return Authorization Number) and instructions on how to return the product to the OPALAuthorized
Service Center, or to the factory. OPAL (or its Authorized Service Center) will initiate corrective repairs upon receipt of the
returned product. Please save original carton and all the packing materials in case shipping is required. All products being
returned to the factory or service center for repairs must be shipped pre-paid.
If the repairs made by OPAL or the OPAL Authorized Service Center are not satisfactory, Owner is instructed to give
written notice to OPAL. If the defect or malfunction remains after a reasonable amount of attempts by OPAL to remedy the
defect or malfunction, the Owner shall then have the option to elect either a refund or replacement of said OPAL product
free of charge. The refund shall be an amount equal to but not greater than the actual purchase price, not including any
taxes, interest, insurance, closing costs and other finance charges (minus reasonable depreciation on the product). If a
refund is necessary, the Owner must make the defective or malfunctioning product available to OPAL free and clear of all
liens or other restrictions.
MODIFICTTIONS OF EQUIPMENT
OPAL reserves the right to modify or change equipment (in whole or part) at any time prior to delivery thereof, in order to
include therein electrical or mechanical improvements deemed appropriate by OPAL; but without incurring any liability to
modify or change any equipment previously delivered, or to supply new equipment in accordance with any earlier
specifications.
DISCLAIMER OF CONSEQUENTIAL AND INCIDENTAL DAMAGES
YOU,THE OWNER, ARE NOT ENTITLED TO RECOVER FROM OPAL ANY INCIDENTAL DAMAGES RESULTING
FROM ANY DEFECT IN THE OPAL PRODUCT. THIS INCLUDES ANY DAMAGE TO ANOTHER PRODUCT OR
PRODUCTS RESULTING FROM SUCH ADEFECT.
WARRANTY ALTERATIONS
No person has the authority to enlarge, amend, or modify this Warranty. This Warranty is not extended by the length of
time which the Owner is deprived of the use of product. Repairs and replacement parts provided pursuant to the
Warranty shall carry only the non-expired portion of the Warranty.
THIS STATEMENT OF WARRANTY SUPERSEDES ALL OTHERS CONTAINED IN THIS MANUAL
NOTES:
PLX Series PLX Series

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The information furnished in this manual does not include all of the details of design and engineering of this
particular product; not does it cover every possible application or situation concerning its usage, which may
occur during the installation, operation or maintenance of said OPAL product.
NOTES:
IMPORTANT
THE PRODUCT REQUIRES CLASS 2 OUTPUT WIRING.
WARNING
TO REDUCE THE RISK OF ELECTRIC
SHOCK, DO NOT EXPOSE THIS
EQUIPMENT TO RAIN OR MOISTURE!
Magnetic Field
CAUTION: Do not locate sensitive high-gain equipment such as preamplifiers or
tape decks directly above or below this 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. This field is strongest just above and
below the unit. If an equipment rack is used, we recommend locating the
amplifier(s) at the bottom of the rack and the preamplifier or other sensitive
equipment at the top.
TO PREVENT ELECTRIC SHOCK, DO
NOT REMOVE TOP OR BOTTOM
COVERS. NO USER SERVICEABLE
PARTS INSIDE. REFER SERVICING
TO QUALIFIED SERVICE
PERSONNEL. DISCONNECT
POWER CORD BEFORE REMOVING
REAR PANEL COVER TO ACCESS
GAIN SWITCH.
Shock Hazard - Do Not Enter
Choc Hasard - N*entrent
Schocke Hazard - Test Nicht
Betrete
Urto Hazard - Do Non Entrano
CAUTION
The exclamation point triangle is used to alert the user to important operating
and/or maintenance instructions.
Printed on recycled paper.
The lightning bolt triangle is used alert the user to the risk of electric shock
PLX Series PLX Series

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Introduction
Congratulations on yourpurchase of aOPAL audio power amplifier. We wouldlike to thank
you for yourconfidence in usand our products.
All the components were specially selected. Although the amplifier was designed to allow
straightforward and uninterrupted operation, improper handling or incorrect installation
could damage thepower amplifier.
Your amplifier represents the latest technology inpower amplifier design. Please read this
manual carefully asit contains informationvital to thesafe operation ofyour amplifier.
Unpacking
Check the cartonbox and itscontents immediately tosee if thereis any signof damage.
Upon unpacking inspect the amplifier, if you detect any damage inform the forwarding
agentwithout delay andask for thedamage to bedocumented.
Claims can onlybe made againstthe forwarder agentby the consignee.
Be sure tosave the cartonand all packagingmaterials for thecarrier's inspection.
It's a good idea to save the carton and packing material even if the amplifier has arrived in
good condition. Should you ever need to ship the unit back to OPAL, or one of its Service
Center. Using only the original factory packaging will be the best way to save the unit from
carrier negligence.
Installation/Mounting
All PLX series models amplifiers are 2- rack space units that can mount in a standard 19"
rack. Four frontpanel mounting holesare provided.
Rear mounting earsgive additional supportespecially important inmobile sound systems.
The unit shouldnot to beinstalled in alocation with:
Toohigh ambient temperature,dust build-up orexcessive humidity;
Fog machines output'soriented to thearea of theamplifier;
Exhaust air ventilatorsand similar unitsnear the areaof the amplifier;
With permanent vibrations;
With excessive inductionor magnetic fieldsdue to tranformersand transmitters;
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Service
This unit has very sophisticated circuitry and should only be serviced by a fully trained
technician.
This is why each unit bears the following label:
To prevent electric shock, do not remove covers. No user serviceable parts inside. Refer
servicing to a qualified technician.
Worldwide Service
Service may be obtained from your local authorized service center. To obtain service, simply
present your sales receipt as proof of purchase along with the defective unit to an authorized
service center. They will handle the necessary paperwork and repair. Remember to transport
your unit in the original factory packaging.
1. When sending a OPAL product to the authorized service center for service, be sure to fill out
the service information form that is enclosed at the end of this manual and include it inside
your unit's shipping pack. Do not send the service information form separately.
2. To ensure the safe transportation of your unit to the authorized service center, ship it in an
original factory-packing container.
3. Do not ship the unit in any kind of rack. Ignoring this warning may result in extensive damage
to the unit and the equipment rack. Accessories are not needed. Do not send the instruction
manual, cables and any other hardware.
The PLXSeries amplifierhas anautomatic powerfactor correctionsystem for a
perfect main network interface. The amplifier is a resistive load for the main network,
minimizing the reactive power and the harmonic distortion on the current. The system allows
performance to be maintained even in circumstances of varying the mains voltage.
PLX Series PLX Series

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Power factor correction
PLX Series isa amplifier constructorto use powerfactor correction. Thisunique feature
ensures that a predominantly resistive load is presented to the mains power supply,
minimizing current distortion and voltage/current displacement This leads to much
improved performance ofthe amplifier athigh levels ofoutput and avoidsmains-voltage
collapses, typical of standard and switching power supplies. Another great advantage
of this technology is that its performance is, to a large extent,independent of the mains
voltage. The ratedoutput power doesnot vary withload/line conditions.
The ShowAlways Goes On
PLX Series is completely protected against every possible error in operation and is
designed to work under every condition. It gives you maximum power with maximum
safety and increases long-term reliability. Anticipating potential problems at the design
stage means yourshow always goeson!
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SPECIFICATIONS
TEST CONDITION
1. Use a 1KHz burst signal (33,3ms ON / 66,6ms OFF). A standard continuous test signal will possibly
activate the Automatic Protect (AP) which limits the max.-output voltage, especially works at 2 Ohms.
2. At high-frequencies (above 10KHz) use a burst signal to avoid engaging the Very High Frequency(VHF)
protection circuit. Otherwise you will not be able to verify the true max. -output voltage at VHF'S.
PLX Series PLX Series
Max output power
EIA at1 kHz and1 % THD,MLS in 0dB position
8 per channel (Watt)
4 per channel (Watt)
2 per channel (Watt)
8 bridged (Watt)
4 bridged (Watt)
THD at 1 kHz and 1 dB below clipping
Slew rate
Dampping Factor
Sensitivity
Input connectors
Link connectors
Mode Switch
Limit Switch
Outut Conneet
Operation voltage
Power factor cos( )
Dimensions ( Wx D x H )
THD at 100Hz and 1 dB below clipping
THD at 10 kHz and 1 dB below clipping
S/N
Channel separation at10 kHz
Output impedance
Impedance
Common mode rejection
Gain controls
Clip/Output headroom indicators
Active
Bridge/Protect (Short, Temp& VHF)
Soft Start Yes
Unit 483 x 481x 89mm
0.10%
50V/ s
0.775V/1V/1.4V
XLR Female
XLR Male
Stereo/Bride/Parallel
On/Off
Speakon
220V-230V 50/60Hz
Packing 560 x 560x 150mm
2000
0.20%
0.15%
102dB
60dB
600
20K BAL/10K UNBAL
60dB
41 Pos detent
Yellow/Green LED
Green LED
Yellow/ Red LED
Switching power
Weight ( kg) Net Weight
Gross Weight
10.7
14
600
900
1150
1800
2250
350
525
660
1050
1350
800
1200
1500
2400
3100
1300
2300
3200
3900
4900
More than 0.95from 200W to full power
11.5
14.75
11.8
15
13.5
16.75
PLX3.0 PLX4.5 PLX5.5 PLX6.5
90V-245V
45V/ s
500

PLX6.5
1
234
567
92
1. Rack mountingears
Two frontpanel mounting holesare provided oneach mounting ear.
2. Fan intakegrill filter
One grill with foam filter is located on the front panel to prevent dust from entering the
amplifier. For easy cleaning of the filter the grill is removable by simply pulling it off. The
foam filter should always be used. The fan's variable speed control ensure low noise
operation and adaptthe quantity ofair required fromthe actual temperatureinside the unit.
Thanks to thisadvanced system lownoise is guarantee.Do not blockthis intake!
3. Input attenuator
Two frontpanel precision 41 steps input attenuator adjust level fortheir respective amplifier
channels. Minimum attenuation (-0dB) equals maximum output. In the bridge mode both
level attenuator must be at thesame position. We recommend that you set CH1 to the -0dB
(full) position.
4. Signal barLED
Each channel hasa bar LED,as the inputsignal strength increase,the green SIGNAL-30dB,
-24dB, -18dB, -12dB,-9dB, -6dB, -3dB,0dB LED indicatorslight respectively.
12 13
12 13 14
15
15
16
17
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Parallel Inputs (Link)
In parallel modeboth channels' inputs are linked andreceive the same signal. The parallel
mode is active if the Link switches are in position "PARALLEL". Both level attenuators are
active, allowing you to set different levels for each channel. Note that only the inputs are
connected in parallel. This is NOT a parallel mono mode. Never connect either positive
output terminal to ground or in parallel.You may use the remaining input connectors to
carry the signal to other amps. NOTE:Always turn off the Link switch when using the
amplifier for Bi-amping.
Stereo Mode
CHANNEL 1
CHANNEL 2
LOUDSPEAKERS
BRIDGEPARALLEL
STEREO
CH 1
CH 2
MIXER
CAUTION: TURN OFF AMPLIFIER
BEFORE CHANGING THIS SWITCH
Bridge Mono Mode
LOUDSPEAKERS
BRIDGEPARALLEL
STEREO
MIXER
CAUTION: TURN OFF AMPLIFIER
BEFORE CHANGING THIS SWITCH
Only use the CH 1 Input
CH 2 isnot used in the mode
Parallel Mono Mode
LOUDSPEAKERS
BRIDGEPARALLEL
STEREO
MIXER
CAUTION: TURN OFF AMPLIFIER
BEFORE CHANGING THIS SWITCH
Only use the CH 1 Input
CH 2 isnot used in the mode
CHANNEL 1
CHANNEL 2
Figure 1
Front Panel
Rear Panel
PLX Series PLX Series
38

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5. Clip/Limiter LED
Each channel hasa LED that light at thereal clipping point (more than 0.5% T.H.D.)and also
indicates the inputsigned is compressedby amplifiers.
6. Protect LED
Each channel has a Protect LED that will light when the load connected is lower than 1 Ohm
or amplifier broken.
7. Bridge LED
The Yellow active LEDilluminates to indicatethat the amplifieris bridge mode.
8. Power LED
The green active LED illuminates to indicate that the amplifier is turned on, and works
correctly.
9. ACpower switch
Use this toswitch on theamplifier.A soft-startsystem limits thestart-up surges.
10. Fan exhaustports
Heated air exitsthe amplifier through the exhaust ports,located on the rear of the amplifier
chassis. Be surenot to blockthis ports, especiallywhen rack mountingthe amplifier.
11. Inputconnectors
XLR female is provided on each channel for balanced or unbalanced input. Unfortunate
wiring, in the proximity of dimmers or other generalised phase controls, motors, trans-
former, etc. can cause interference into your system. You will hear loud humming or a
bumping noise in the loudspeakers. Balanced wiring suppresses these noises quite
significantly.
12. Selectable Limit function
The switch enablethe Limit circuitlocated on settingsboard.
13. Input Sensitivity/Gain
The standard settings are:0.775V/1V/1.4V,selection is independent for each channel. Use
this function to match the amplifier's sensitivity/gain with the other connected equipment.
As option, ispossible adjust the unit for any sensitivity/gain.Note that everyincrease of the
gain will decreasethe S/N ratio.
14. Mode operationswitches
Setup these switchesfor the desiredoperation mode.
15. Speakon outputconnectors
The unit hasfour Speakon connectorsas outputs: CH1 and CH2. Every onepermit the con-
nection of both channels for stereo operation or parallel mode. For bridge operation the
CH1 connector shouldbe used.
work at
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17. S.N. label
Every unit hasa label indicating:the model, andthe barcode serialnumber.
Operation
Connecting Power andCircuit size requirements
Amplifier's power requirement arerated at idle, at 1/8 and1/3 power ("severe" music con-
dition).The maximum power current draw rating is limited only by the internal fuses.
Consult the specification at the end of this manual for the power each amplifier will
demand. Mains voltage must also be correct and the same as that printed on the rear of
the amplifier. Damage caused by connecting the amplifier to improper AC voltage is not
covered by anywarranty.
Note: always switch off and disconnect the amplifier from mains voltage before making
audio connections, and as an extra precaution, have the attenuators turned down during
power-up.
Cooling Requirements
Amplifier use a forced air cooling system to maintain a low, even operating temperature.
Drawn by a infinitely variable speed fans mounted inside the unit, air enters through the
front grills withdust filter,and courses through the cooling fins of the heatsinks,which dis-
sipates power transistor heat, before exiting through the rear panel ports. Make sure that
there is enough space around the front of the amplifier to allow air to enter, and around
the units toallow the heatedair to exit.If the ampis rack-mounted, do not use doors or cov-
ers on the front and rear of the rack; the air must flow through the amplifier without resis-
tance.
Note: whatever typeof rack youare using, makesure that theheated air canescape freely,
and that thereis not resistanceto the intakeof cool airthrough the frontgrill.
Configuration
Use the configuration switch and the internal jumpers to configurate the amplifier to meet
your requirements. The setup must be done with the unit switched off. With the switches
and jumpers ispossible to configuratethe amplifier forthe following functions:
Stereo Mode (standard)
In stereo mode, the channels operate independently, with their input attenuators control-
ling the respective channel's level. Recommended minimum nominal load impedance for
stereo operation is 4 or 2 Ohms per channel (as indicated on the specifications).
Loudspeakers are connected to the speakon outputs CH 1 or CH 2. For reference see
Bridged Mono Mode
In Bridged Mono mode, both amplifier channels work with the same input signal, but with
inverse phases.The result is a doubling of the output voltage and thus double the power
on the double impedance. If the amplifier is to be operated in Bridged Mono mode, ONLY
one input may be used CH1. We recommend that you set them to the -0dB (full) position.
Loudspeakers are connectedto the speakonoutput CH 1.For reference seeFigure 1.
Figure 1
16. A.C.Power cable
The unit haveone A.C.power cable. Beforeconnection, be surethat the cable is not frayed
or broken. Theconnection must be madeonly in a plugwith the electrical groundwire system.
PLX Series PLX Series