QSC Audio ISA 450, ISA 500Ti, ISA 280, ISA 800Ti, ISA 300Ti User Manual 2

Installed Sound Professional Audio Amplifiers

• ISA 280

• ISA 450

• ISA 750

• ISA 1350

• ISA 300Ti

• ISA 500Ti

User Manual

EN

• ISA 800Ti

Manual del Usario

Manuel de l’utilisateur

Bedienhandbuch

用户手册

ES

FR

DE

CH

*TD-000136-00*

TD-000136-00 Rev.B

EN

Important Safety Precautions & Explanation of Symbols

CAUTION: TO REDUCE THE RISK OF ELECTRIC SHOCK, DO NOT REMOVE THE COVER. NO
USER-SERVICEABLE PARTS INSIDE. REFER SERVICING TO QUALIFIED PERSONNEL.

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
humans.

The exclamation point within an equilateral triangle is intended to alert the user to the pres­ence of important operating and maintenance (servicing) instructions in this manual.

The lightning flashes printed next to the OUTPUT terminals of the amplifier are intended to
alert the user to the risk of hazardous energy. Output connectors that could pose a risk are
marked with the lightning flash. Do not touch output terminals while amplifier power is on.
Make all connections with amplifier turned off.

WARNING: To prevent fire or electric shock, do not expose this equipment to rain or mois­ture.

This amplifier has a serial number located on the rear panel.
Please write this and the model number down and keep them for your records.
Keep your purchase receipt. It is your proof of purchase.

Serial Number:______________________________
Date of Purchase:____________________________
Purchased From:_____________________________

© Copyright 2003, QSC Audio Products, Inc.

“QSC” and the QSC logo are registered with the U.S. Patent and Trademark Office

2

QSC® is a registered trademark of QSC Audio Products, Inc.

All trademarks are the property of their respective owners.

Introduction

Thank you for purchasing this QSC power amplifier. Please read the following directions to obtain the best results.

Key Features:

•ISA 280, 450, 750, and 1350 models: 2 channels at 2 ohms (min.) impedance, bridgeable into 4 ohms (min.) impedance.

•ISA “Ti” models: low impedance outputs and

•QSC DataPort V2 connects to optional QSC signal processing accessories and amplifier monitoring systems.

•Mode switches Stereo, Bridge Mono, and Parallel Input operation.

• Independent Clip Limiter and Low Frequency Filter settings for each channel.

•ISA 1350 equipped with front panel Protect mode LED indicator.

•QSC durability and performance.

isolated 70V or 100V for distributed audio systems, bridgeable for 140V and 200V.

EN

1- Cooling Air Exhaust Vents
2- Power On Indicator (ISA 1350 has Protect LED also)
3- Power Switch
4- Clip and Signal Presence Indicators for each channel
5- DataPort V2 Connector
6- Terminal block input connectors
7- Gain Controls
8- XLR input Connectors (locking)
9- Mode Switches (Clip Limiter, Operating Mode, Low-Frequency Filters)

Unpacking

Factory packed carton contains:

• the amplifier

• this User Manual

• IEC-type detachable power cord

Use the same type carton when shipping the amplifier.

10- Mode Switch Settings
11- Bridge Mode Switch Settings and Notes
12- Cooling Air Intake
13- Output Connectors (Ti model shown)
14- Tabs for Securing Output Wires
15- Serial Number Decal
16- AC Power Circuit Breaker (ISA 1350 has two breakers)
17- IEC Power Connector
18- Mounting Holes for Optional Handles

• rear rack ear mounting kit

• 3-pin terminal block connectors (2)

• rubber feet for non-rack mount installations (4)

3

EN

Rack Mounting

Use four screws and washers to mount the
amplifier to the equipment rack rails. To use the
amplifier outside a rack, attach the self-adhe­sive rubber feet to the bottom.

Cooling

Air flows from the rack, into the back of the amplifier, and out
the front. This keeps the rack cool. The fan automatically runs
faster when the amp is working hard.

Do not block the rear intake or front air vents!

AC Mains

Connect AC power to the IEC socket on the back of the ampli­fier. NOTE: Turn off the AC power switch before connecting AC
power.

The correct AC line voltage is shown on the serial number label, on the rear panel. Connecting to the wrong line voltage may damage the amplifier or increase the risk of electric shock.

Setting the Mode Switches

The rear panel mode switches control the amplifier’s operating
mode, and each channel’s independent clip limiting and low fre­quency (LF) filtering. All models Clip Limiter switch settings are
the same. However, Operating Mode and Low Frequency Filter
settings are different for the Ti models. The rear panel label
shows this information for convenient reference.

Setting Clip Limiters

Air flow in QSC amplifiers: Cool air is drawn into the rear of the amplifier by the cooling fan. Warm air exits the front of the amplifier.

Each channel has a clip limiter with its own on-off switch. The
limiter only responds to actual clipping, and automatically com­pensates for load and voltage variations. Clip limiting is gener­ally recommended, especially to protect high frequency drivers.

4

Switch 1 controls CH1.
Switch 10 controls CH2.
Set switch to RIGHT to use Clip Limiting.

Selecting Stereo, Parallel, or Bridge Mode

The amplifier can be set for normal Stereo
mode, Parallel Input mode, or Bridge Mono
mode.

Stereo Mode- Each channel remains inde­pendent, and may be used for two different
signals.

Parallel Mode - This setting connects
both inputs together. One signal feeds both
channels. Each channel's Gain control and
speaker connection remain independent.

Bridge Mode- This setting combines both
channels of a pair into a single channel
with twice the output voltage. Use only the
first channel's input and Gain control. Set
the second channel's Gain control at mini­mum. The load must be rated for the higher
power (or voltage) and is connected as
shown on pages 6 and 7.

Do not connect more than one input when operating in parallel or bridge mode.

ISA 280/450/750/1350

Stereo Mode ­Switches 4, 5, 6 and 7
are all set to the LEFT
position.

Parallel Mode ­Switches 4 and 5 are
set to the RIGHT posi­tion.
Switches 6 and 7 are
set to the LEFT posi­tion.

Bridge Mode­Switches 4, 5, 6, 7, and
8 are all set to the
RIGHT position.
Switch 10 is set to the
LEFT position.

ISA 300Ti/ 500Ti/800Ti

Ti Stereo Mode ­Switches 3, 4, 5, 6, 7,
and 8 are all set to the
LEFT position.

EN

Ti Parallel Mode ­Switches 3, 4, and 5
are set to the RIGHT
position.
Switches 6, 7, and 8
are set to the LEFT
position.

Ti Bridge Mode­Switches 3, 4, 5, 6, 7,
and 8 are all set to the
RIGHT position.
Switch 10 is set to the
LEFT position.

Setting Low Frequency Filters

ISA 280, ISA 450, ISA 750 and ISA 1350:

Use of the Low Frequency Filters is recom­mended. Use the appropriate switch set­tings to turn the filter ON or OFF and to
select the filter frequency. When set to the
ON position, the channel has a 12dB per
octave Low Frequency filter to limit subau­dio cone movement, making more power
available for the loudspeaker’s rated fre­quency range. The filter should only be
turned OFF for driving subwoofers.

ISA 300Ti, ISA 500Ti, and ISA 800Ti: The
Low Frequency Filters are always active
and not defeatable. Each channel has a
12dB per octave Low Frequency filter to
prevent saturation of the 70V loudspeaker
transformers. This reduces distortion and
prevents amplifier overload. The 50 Hz set­ting usually works well with high quality
loudspeaker transformers. The 75 Hz set­ting works well with speech-grade loud­speakers and transformers.

Low Frequency Filter­Switches 2 and 3 con­trol CH1. Switches 8
and 9 control CH2.
Switches 3 and 8 turn
the LF filter ON or OFF.
Switches 2 and 9
select 30Hz or 70 Hz.

Ti Low Frequency Filter­Switch 2 controls CH1.
Switch 9 controls CH2.
Switches 2 and 9 select
50Hz or 75 Hz.

5

EN

Inputs

Each channel has a balanced XLR and terminal block input. The
input impedance is 20k ohm balanced or 10k ohm unbalanced.

Balanced connections are recommended for less AC hum and
interference, especially with long cable runs. Unbalanced con­nections may be suitable for short cables. The signal's source
impedance should be less than 600 ohms. If the DataPort is
being used to provide input signals to the amplifier, do not
connect input signals to the XLR or terminal block connectors.

If unbalanced connection is necessary, connect the signal con­ductor to the connector’s + pin and the shield to the ground
pin. Connect a jumper between the ground pin and the - pin.

Direct Low Impedance Outputs

Direct Low Impedance Output connections are shown on the
back of the chassis, to the right of the output terminals. Care­fully note the polarity marks, which are arranged to make
Bridge Mode connections easier.

Balanced Terminal Block inputs: Strip
the wire ¼ inch (6 mm) and connect to
the plug as shown. Be sure to tighten
the screws firmly.

Unbalanced Terminal Block inputs:
Strip the wire ¼ inch and connect to
the plug as shown. The middle pin
must be connected to the shield pin
as shown. Be sure to tighten the
screws firmly.

Balanced XLR inputs: Con­nect to the plug as shown.

Unbalanced XLR inputs: Con­nect to the plug as shown.
The - pin must be connected
to the shield pin as shown.

Stereo and Parallel Mode- Connect each loudspeaker load

to its own channel of the amplifier, as shown on the chassis
label to the right of the terminals. The mode configuration
switches, page 5, must be set for Stereo or Parallel mode.

Bridge Mode- Bridge mode configures the amplifier to drive
a single, high power loudspeaker load. See page 5 to set the
Bridge Mode switches. Connect the load as shown on label to
the right of the terminals. Use the center two terminals
labelled BRIDGE MONO. 4 ohms is the minimum impedance in
bridged mode. Use Stereo or Parallel mode channels to drive 2
ohm loads.

BRIDGE MODE PRECAUTIONS: Do not use less
than 4 ohm loads in bridge mode! 4 ohms is the
minimum impedance for bridge mode operation.

OUTPUT TERMINAL SAFETY WARNING! Do not
touch output terminals while amplifier power is
on. Make all connections with amplifier turned
off. Risk of hazardous energy!

WARNING! Risk of hazardous energy! Class 2
wiring shall be used.

ISA 1350 WARNING!: Use proper speaker wire.
Class 2 wiring shall be used. For bridged mono
mode, Class 3 wiring shall be used.

6

Direct Low Impedance Outputs: Connect the loudspeakers as shown on the label next to the output terminals. Note Bridge Mono connection (center terminals) and polarity!

Isolated Distributed Line Outputs:
ISA 300Ti, ISA 500Ti, and ISA 800Ti
Models Only

Wiring connections are shown on the back of the chassis.
STEREO and PARALLEL connections are shown on the right
side of the terminals, and BRIDGE mode is shown on the
left side. Carefully note the polarity marks, which are
arranged to make Bridge Mode connections easier.

Stereo and Parallel Mode- Connect each 70V/100V cir­cuit to its own channel of the amplifier, as shown on the
label, right of terminals. The mode configuration switches,
page 6, must be set for Stereo or Parallel mode.

Bridge Mode- Bridge mode configures the amplifier to
drive a single 140V/200V audio circuit. See page 6 to set
the Bridge Mode switches. Connect a jumper wire

between CH1 [0] and CH2 [0] terminals.

Connect the load as shown on the label, left of the termi­nals. Connect only 140V/200V distributed audio circuits in
bridged mode. Use Stereo or Parallel mode channels to
drive 70V loads.

OUTPUT TERMINAL SAFETY WARNING! Do
not touch output terminals while amplifier
power is on. Make all connections with
amplifier turned off. Risk of hazardous
energy!

WARNING! Class 2 wire shall be used. For
isolated distributed 140V and 200V, Class 3
wire shall be used.

EN

70V/100V Stereo or Parallel connection: Each 70V/ 100V zone connects to its respective channel. Ensure that all speaker connections maintain proper polarity.

140V/200V Bridge connection: Wire each bridged pair to a 140V/200V circuit as shown. Connect a jumper wire between CH1 [0] and CH2 [0] terminals. Check for proper polarity.

ATTENTION! BRIDGE MODE CONNECTIONS:
Connect a jumper wire between CH1 [0] and
CH2 [0] terminals. The isolated output feature
requires this jumper connection for bridge
mode operation.

DataPort

The DataPort V2 connects to optional QSC accessories and
processing devices. DataPort devices provide remote mon­itoring, DSP processing, filter and crossover functions.
Amplifier Standby is not supported.

If using the DataPort for input signals, do not use the Ter­minal Block or XLR inputs.

If the amplifier is being used in a system monitored
through a QSC cinema monitor (or other QSC DataPort V2
supporting product) CH1 and CH2 output voltages and AC
power status will be reported by the DataPort.

DataPort V2 connector.

NOTE! If using the DataPort
V2 connection for signal

input, the unused XLR or ter­minal block connectors may be used
for daisy chaining the input signal to
other amplifiers. However, note the
signal will be 10 dB down from the
signal applied to the DataPort.

7

LED Indicators

The LED indicators can be used to monitor system operation and identify common problems.

POWER: A single GREEN LED, on left side of AC Power switch.

Normal indication: AC switch ON: LED will illuminate.

EN

If no indication: Check AC power cord and AC outlet.

CLIP: Two RED LEDs, one indicator for each channel.

Normal indication: illuminates whenever the amplifier is driven beyond full power. The resulting distor-

tion corresponds to the brightness of the LED. Distortion that causes only brief flashing may not be audi­ble.
During muting, the LED fully illuminates. This occurs during normal “On-Off” muting.

Abnormal indication:

Bright red illumination while the amp is being used indicates either thermal muting or a shorted output.
If the amplifier overheats, the fan will run at full speed, and operation should resume within one minute.
Allow the fan to run, and make sure the amplifier ventilation is adequate.
A shorted or overloaded output circuit will cause excessive Clip flashing and possible overheating.
If distortion is audible without a Clip indication, the problem is either before or after the amplifier. Check
for damaged speakers or overloaded signal source. The amplifier Gain control should be in the upper half
of its range to prevent input overload.

SIGNAL: Two GREEN LEDs, one indicator for each channel.

Normal indication: illuminates when the input signal is strong enough to drive the output to -40 dB from

rated 8 ohm power. As signal approaches full power, the LED will illuminate continuously.

If no indication: check Gain settings and increase gain if necessary. Check input connections and audio
source for signal. If the Clip LED illuminates with little or no Signal indication, check the output wiring for
shorts.

Power on indicator.

Clip and Signal indicators for both channels.

Abnormal indication: If the Signal LED illuminates with no signal input, there may be system oscillations

or some other malfunction. Disconnect the load and fully reduce the gain. If the signal LED remains on, the
amp may need servicing.

PROTECT (ISA 1350 only): A single RED LED directly below the POWER LED on left side of AC

Power switch.

Normal indication: not illuminated (NOTE!: If both rear panel AC circuit breakers are open, the PROTECT

LED and the POWER ON LED will not illuminate)

Abnormal indication: illuminated. If the PROTECT LED illuminates, the amplifier is in thermal protect or
one of AC circuit breakers has opened. If the amplifier is hot, leave the AC power switch ON so that the fan
cools the amplifier off. Normal operation will resume automatically after the amplifier has cooled suffi­ciently. If an AC circuit breaker (rear panel) has opened, reset the breaker by pushing inward on its reset
button.

Gain Controls

Turn the gain controls clockwise to increase gain and counterclockwise to decrease gain.

The Gain controls are marked in dB of attenuation. There are 11 detents for repeatable adjustments. The
upper 6 steps are about 2 dB each, and settings should normally be made within this range. The range
below -10 dB should not be used for normal program levels, as the input headroom could be exceeded, but
can be used for testing at reduced levels. At the minimum setting, the signal is completely cut off.

The Gain controls can be adjusted by grasping the control shaft and rotating.

Gain controls are located on the rear panel.

8

Specifications (all models)

DYNAMIC HEADROOM 2 dB at 4 ohms

DISTORTION SMPTE-IM Less than 0.01%

SIGNAL TO NOISE -100 dB (unweighted, 20 Hz.-20 kHz.)

INPUT CLIPPING +22 dBu, 10 Vrms (ISA 1350: +15.3 dBu, 4.53 Vrms)

INPUT IMPEDANCE 10k ohms unbalanced, 20k ohms balanced

AMPLIFIER PROTECTION Short circuit, open circuit, thermal, ultrasonic and RF protection. Stable into reactive or mismatched loads.

LOAD PROTECTION Turn-on/turnoff muting, AC coupling (DC fault blocking), Clip limiting.

COOLING Continuously variable speed fan; back-to-front air flow through heat sink tunnel

LED INDICATORS POWER (green), SIGNAL (green, 1 per channel) and CLIP (red, 1 per channel)

ISA 1350: also equipped with Protect LED (red)

CONNECTORS Input: (2) 3-pin terminal block and (2) XLR

Output: screw terminal barrier strip
Control & Monitoring: (1) QSC DataPort V2

POWER REQUIREMENTS Refer to voltage specified on rear panel serial number label. Configured at factory for 100, 120 or 230

VAC, 50- 60 Hz.

EN

CONTROLS & INDICATORS Front: AC POWER switch

Back: gain controls, 10-position DIP switch block (Clip Limiters, Stereo/Parallel/Bridge mode selection,

Low frequency filter on/off (low impedance models only), Low frequency filter selection of 30/70 Hertz
(low impedance models) or 50/75 Hertz (Ti models), and AC circuit breaker (2 breakers on ISA 1350).

DIMENSIONS 19.0" (48.3 cm) wide, 5.2" (13.2 cm) tall (3 rack spaces) 15.90" (40.4 cm) deep

SPECIFICATIONS SUBJECT TO CHANGE WITHOUT NOTICE

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Specifications: ISA 280, ISA 450, ISA 750, and ISA 1350

OUTPUT POWER in watts ISA280 ISA 450 ISA 750 ISA 1350

FT C:

8 ohms, 2 channels driven 185 260 450 800 (20 Hz - 20 kHz, 0.1% THD) 4 ohms 2 channels driven 280 400 650 1300 (20 Hz - 20 kHz, 0.1% THD)

EIA:

16 ohms, 1 channel driven 100 140 250 475 (1 kHz, 0.1% THD) 8 ohms, 1 channel driven 200 280 475 850 (1 kHz, 0.1% THD) 4 ohms, 1 channel driven 300 450 750 1400 (1 kHz, 0.1% THD) 2 ohms, 2 channels driven 430 700 1200 2000 (1 kHz, 1.0% THD)

EN

Bridged Mono:

16 ohms 370 520 900 1600 (20 Hz - 20 kHz, 0.1% THD) 8 ohms 600 900 1500 2800 (1 kHz, 0.1% THD) 4 ohms 830 1400 2400 4000 (1 kHz, 1.0% THD)

FREQUENCY RESPONSE +0.0, -1.0 dB: 20 Hz to 20 kHz (LF filter OFF, at -10 dB from rated power), -3 dB points: 5 Hz and 50 kHz.

DAMPING FACTOR >200 at 8 ohm load >200 at 8 ohm load >200 at 8 ohm load >250 at 8 ohm load

INPUT SENSITIVITY +3.43 dBu (1.15 Vrms) +2.81 dBu (1.07 Vrms) +2.81 dBu (1.07 Vrms) +4.08 dBu (1.24 Vrms)

VOLTAGE GAIN 30.5 dB (33.4 x) 33.0 dB (44.7 x) 35.0 dB (56.2 x) 36.1 dB (64.0x)

OUTPUT CIRCUIT TYPE AB AB H 2-tier H 3-tier

CURRENT CONSUMPTION (Ampere, rms, both channels driven, 120 VAC*)

Idle 0.5 0.5 0.6 1.3
1/8 power**, 8 ohms 3.0 3.7 4.0 6.2
1/8 power**, 4 ohms 4.5 6.0 6.3 9.9
1/8 power**, 2 ohms 6.5 9.3 9.2 14.0

* NOTE: for 240 VAC models, multiply all values by 0.5 (one-half).

** NOTE: 1/8 power is representative of typical program material with occasional clipping.

WEIGHT 36 pounds (20.0 kg) 36 pounds (20.0 kg) 47 pounds (25.0 kg) 68 pounds (30.8 kg)

10

SPECIFICATIONS SUBJECT TO CHANGE WITHOUT NOTICE

Specifications: ISA 300Ti, ISA 500Ti, and ISA 800Ti

OUTPUT POWER in watts ISA 300Ti ISA 500Ti ISA 800Ti

FT C:

8 ohms, 2 channels driven 185 260 450
(20 Hz - 20 kHz, 0.1% THD)
4 ohms 2 channels driven 280 400 650
(20 Hz - 20 kHz, 0.1% THD)

EIA:

16 ohms, 1 channel driven 100 140 250
(1 kHz, 0.1% THD)
8 ohms, 1 channel driven 200 280 475
(1 kHz, 0.1% THD)
4 ohms, 1 channel driven 300 450 750
(1 kHz, 0.1% THD)
2 ohms, 2 channels driven 430 700 1200
(1 kHz, 1.0% THD)

Bridged Mono:

16 ohms 370 520 900
(20 Hz - 20 kHz, 0.1% THD)
8 ohms 600 900 1500
(1 kHz, 0.1% THD)
4 ohms 830 1400 2400
(1 kHz, 1.0% THD)

EN

Distributed High Impedance (per channel):

70 Volt per channel 300 500 800
(50 Hz - 16 kHz, 0.5% THD)
100 Volt per channel 300 500 800
(50 Hz - 16 kHz, 0.5% THD)
140 Volt bridged, single channel 600 1000 1600
(50 Hz - 16 kHz, 0.5% THD)
200 Volt bridged, single channel 600 1000 1600
(50 Hz - 16 kHz, 0.5% THD)

FREQUENCY RESPONSE

Direct Outputs -3.0, -0.5 dB: 50 Hz to 20 kHz (LF filter 50 Hz, 10 dB from rated power)
Isolated Outputs +0.0, -3.0: 50 Hz to 16 kHz (LF filter 50 Hz, at -10 dB from rated power)

OUTPUT REGULATION 1.5 dB no-load to full-load

INPUT SENSITIVITY

Direct Low Impedance Outputs +3.43 dBu (1.15 Vrms) +2.81 dBu (1.07 Vrms) +2.81 dBu (1.07 Vrms)
Isolated Distributed Line Outputs (Ti only) +2.20 dBu (1.00) Vrms) +1.80 dBu (0.95 Vrms) +1.80 dBu (0.95 Vrms)

Full load, 70/100V

VOLTAGE GAIN

Direct Low Impedance Outputs 30.5 dB (33.4 x) 33.0 dB (44.7 x) 35.0 dB (56.2 x)

OUTPUT CIRCUIT TYPE AB AB H 2-tier

CURRENT CONSUMPTION (Ampere, rms, both channels driven, 120 VAC*)

Idle 0.5 0.5 0.6
1/8 power**, 8 ohms 3.0 3.7 4.0
1/8 power**, 4 ohms 4.5 6.0 6.3
1/8 power**, 2 ohms 6.5 9.3 9.2
1/8 power**, 70V/100V 5.5 6.9 8.5

* NOTE: for 240 VAC models, multiply all values by 0.5 (one-half).

** NOTE: 1/8 power is representative of typical program material with occasional clipping.

WEIGHT 44 pounds (20.0 kg) 44 pounds (20.0 kg) 55 pounds (25.0 kg)

SPECIFICATIONS SUBJECT TO CHANGE WITHOUT NOTICE

11

EN

Warranty Information & How To Contact QSC

Warranty (USA only; other countries, see your dealer or distributor)

Disclaimer

QSC Audio Products, Inc. is not liable for any damage to speakers, or any other equipment that is caused by negligence or improper
installation and/or use of this amplifier product.

QSC Audio Products 3 Year Limited Warranty

QSC Audio Products, Inc. (“QSC”) guarantees its products to be free from defective material and / or workmanship for a period of three
(3) years from date of sale, and will replace defective parts and repair malfunctioning products under this warranty when the defect
occurs under normal installation and use - provided the unit is returned to our factory or one of our authorized service stations via pre­paid transportation with a copy of proof of purchase (i.e., sales receipt). This warranty provides that the examination of the return prod­uct must indicate, in our judgment, a manufacturing defect. This warranty does not extend to any product which has been subjected to
misuse, neglect, accident, improper installation, or where the date code has been removed or defaced. QSC shall not be liable for inci­dental and/or consequential damages. This warranty gives you specific legal rights. This limited warranty is freely transferable during
the term of the warranty period.

Customer may have additional rights, which vary from state to state.

In the event that this product was manufactured for export and sale outside of the United States or its territories, then this limited war­ranty shall not apply. Removal of the serial number on this product, or purchase of this product from an unauthorized dealer, will void
this limited warranty.

Periodically, this warranty is updated. To obtain the most recent version of QSC's warranty statement, please visit www.qscaudio.com.

Contact us at 800-854-4079 or visit our website at www.qscaudio.com.

How to Contact QSC Audio Products

Mailing address: QSC Audio Products, Inc.

1675 MacArthur Boulevard
Costa Mesa, CA 92626-1468 USA

Telephone Numbers: Main Number [phone]

Sales & Marketing [phone] or toll free (USA only) [phone]
Customer Service(714) 957-7150 or toll free (USA only) [phone]

Facsimile Numbers: Sales & Marketing FAX[phone]

Customer Service FAX[phone]

World Wide Web: www.qscaudio.com

E-mail: [e-mail]

[e-mail]

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QSC Audio Products, Inc. 1675 MacArthur Boulevard Costa Mesa, California 92626 USA

“QSC” and the QSC logo are registered with the U.S. Patent and Trademark Office.

©2003 QSC Audio Products, Inc.

Precauciones importantes de seguridad y explicación de los símbolos

PRECAUCIÓN: PARA REDUCIR EL RIESGO DE DESCARGA ELÉCTRICA, NO QUITE LA
CUBIERTA. EL INTERIOR NO CONTIENE PIEZAS A LAS QUE EL USUARIO PUEDA DAR
SERVICIO. REFIERA EL SERVICIO A PERSONAL CALIFICADO.

El símbolo del rayo con una punta de flecha dentro de un triángulo equilátero tiene la
intención de alertar al usuario de la presencia de voltaje "peligroso" no aislado dentro de la
caja del producto, que puede ser de magnitud suficiente para constituir un riesgo de
descarga eléctrica a los seres humanos.

El signo de exclamación dentro de un triángulo equilátero tiene la intención de alertar al
usuario de la presencia de importantes instrucciones de operación y mantenimiento
(servicio) en este manual.

Los rayos impresos cerca de los terminales de SALIDA del amplificador tienen la intención
de alertar al usuario del riesgo de energía peligrosa. Los conectadores de salida que
pudiesen representar un riesgo están marcados con el símbolo del rayo. No toque los
terminales de salida mientras el amplificador está encendido. Asegúrese de que todas las
conexiones con el amplificador estén apagadas.

ES

ADVERTENCIA: Para prevenir incendios o descargas eléctricas, no exponga este equipo a
la lluvia ni a la humedad.

Este amplificador tiene un número de serie colocado en el panel posterior.
Por favor anote este número y el número de modelo y guárdelos para sus archivos.
Conserve su recibo de compra. Es el comprobante de su compra.

Número de serie:______________________________
Fecha de la compra:____________________________
Comprado en:_____________________________

© Derechos de autor 2003, QSC Audio Products, Inc.

QSC® es una marca comercial registrada de QSC Audio Products, Inc.

“QSC” y el logo QSC están registrados con la Oficina de Patentes y Marcas Comerciales de EE.UU.

Todas las marcas comerciales son propiedad de sus respectivos dueños.

13

ES

Introducción

Muchas gracias por la compra de este amplificador de potencia QSC. Por favor lea las siguientes instrucciones para obtener resultados óptimos.
Características clave:

•Modelos ISA 280, 450, 750 y 1350: 2 canales a 2 ohmios (mín.) de impedancia, puenteables a 4 ohmios (mín.) de impedancia.

•Modelos ISA “Ti”: salidas de baja impedancia y

•El QSC DataPort V2 se conecta a accesorios de procesamiento de señales y a sistemas de supervisión del amplificador QSC opcionales.

•Conmutadores de modo de operación de entrada estéreo, monopuenteado y paralela.

•Limitador de recorte independiente y ajustes de filtro de baja frecuencia para cada canal.

•El modelo ISA 1350 está equipado con un indicador LED de modo de protección en el panel frontal.

•La durabilidad y el rendimiento de QSC.

aisladas de 70V o 100V para sistemas de audio distribuido, puenteables a 140V y 200V.

Desembalaje

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1- Ventilas de descarga del aire de enfriamiento
2- Indicador de encendido (el modelo ISA 1350 también tiene un LED de

protección)
3- Conmutador de encendido
4- Indicadores de recorte y de presencia de señal para cada canal
5- Conectador DataPort V2
6- Conectadores de entrada del bloque de terminales
7- Controles de ganancia
8- Conectadores de entrada XLR (bloqueo)
9- Conmutadores de modo (Limitador de recorte, Modo de operación,

Filtros de baja frecuencia)

La caja empacada en fábrica contiene:

• el amplificador

• este Manual para el Usuario

• cable de alimentación desprendible tipo IEC

Cuando embarque el amplificador utilice el mismo tipo de caja.

10- Ajustes del conmutador de modo
11- Ajustes y notas del conmutador de modo puenteado
12- Entrada del aire de enfriamiento
13- Conectadores de salida (se muestra el modelo Ti)
14- Lengüetas para asegurar los cables de salida
15- Calcomanía del número de serie
16- Disyuntor de CA (el modelo ISA 1350 tiene dos disyuntores)
17- Conectador de potencia IEC
18- Orificios de montaje para asas opcionales

• juego de montaje de orejeta de bastidor posterior

• conectadores de tres patas al bloque de terminales (2)

• patas de caucho para las instalaciones de montaje que no sean
en bastidor (4)

Montaje en bastidor

Use cuatro tornillos y arandelas para montar el
amplificador en los rieles del bastidor del equipo.
Para usar el amplificador sin bastidor, instale las
patas de caucho autoadhesivas en la parte inferior.

Enfriamiento

El aire fluye desde el bastidor hacia el interior por la parte posterior
del amplificador y hasta afuera por la parte frontal. Este mantiene el
bastidor frío. El ventilador automáticamente funciona más rápido
cuando el amplificador está trabajando mucho.

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¡No bloquee la toma posterior ni las aberturas de ventilación de la parte frontal!

Línea principal de CA

Conecte la CA en el receptáculo IEC que se encuentra en la parte
posterior del amplificador. NOTA: Apague el conmutador de CA antes
de conectar la CA.

El voltaje correcto de la línea de CA se muestra en la etiqueta del número de serie que se encuentra en el panel posterior. Si se conecta un voltaje de línea incorrecto se puede dañar el amplificador o aumentar el riesgo de una descarga eléctrica.

Ajuste de los conmutadores de modo

Los conmutadores de modo del panel posterior controlan el modo de
operación del amplificador, y la limitación de recorte independiente y
la filtración de baja frecuencia (LF) de cada canal. Los ajustes del
conmutador limitador de recorte de todos los modelos son los mismos.
Sin embargo, los ajustes de Modo de operación y de Filtro de baja
frecuencia son diferentes para los modelos Ti. La etiqueta del panel
posterior contiene esta información para su conveniente referencia.

Ajuste de los limitadores de recorte

Cada canal tiene un limitador de recorte con su propio conmutador de
encendido y apagado. El limitador sólo responde al recorte real, y
compensa automáticamente las variaciones de carga y de voltaje.
Generalmente se recomienda la limitación de recorte, especialmente
para proteger excitadores de alta frecuencia.

Flujo de aire en los amplificadores QSC: El aire frío es arrastrado hacia el interior de la parte posterior del amplificador por el ventilador de enfriamiento. El aire caliente sale por el frente del amplificador.

El conmutador 1 controla CH1.
El conmutador 10 controla CH2.
Ajuste el conmutador a la DERECHA para usar
la limitación de recorte.

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Selección del modo Estéreo, Paralelo o Puenteado

El amplificador se puede ajustar en modo
estéreo normal, modo de entrada paralela o
modo mono puenteado.

Modo estéreo: cada canal permanece
independiente, y se puede usar para dos
señales diferentes.

Modo paralelo: este ajuste conecta ambas
entradas juntas. Una señal alimenta ambos
canales. El control de ganancia y la conexión del
altavoz de cada canal permanecen
independientes.

Modo puenteado: este ajuste combina ambos
canales de un par en un solo canal con dos
veces el voltaje de salida. Use sólo la entrada y
el control de ganancia del primer canal. Ajuste
el control de ganancia del segundo canal al
mínimo. La carga debe estar clasificada para la
potencia (o voltaje) mayor y está conectada
como se muestra en las páginas 6 y 7.

No conecte más de una entrada cuando opere en modo paralelo o puenteado.

ISA 280/450/750/1350

Modo estéreo: los conmutadores 4, 5, 6 y 7 todos están ajustados en la posición IZQUIERDA.

Modo paralelo - Los
conmutadores 4 y 5 están
ajustados en la posición
DERECHA.
Los conmutadores 6 y 7
están ajustados en la
posición IZQUIERDA.

ISA 300Ti/ 500Ti/800Ti

Modo estéreo Ti - Los conmutadores 3, 4, 5, 6, 7 y 8 están todos ajustados en la posición IZQUIERDA.

Modo paralelo Ti - Los
conmutadores 3, 4 y 5
están ajustados en la
posición DERECHA.
Los conmutadores 6, 7 y
8 están ajustados en la
posición IZQUIERDA.

Ajuste de los filtros de baja frecuencia

Modelos ISA 280, ISA 450, ISA 750 e ISA
1350: Se recomienda el uso de los filtros de baja

frecuencia. Use los ajustes apropiados del
conmutador para ENCENDER y APAGAR el filtro
y para seleccionar la frecuencia del filtro.
Cuando se ajusta en la posición ENCENDIDO, el
canal tiene un filtro de baja frecuencia de 12dB
por octava para limitar el movimiento del cono
del subaudio, liberando más potencia para la
amplitud de frecuencia nominal del altavoz. El
filtro sólo se debe APAGAR para los subwoofers
excitadores.

Modelos ISA 300Ti, ISA 500Ti e ISA 800Ti:
Los filtros de baja frecuencia siempre están
activos y no se pueden anular. Cada canal tiene
un filtro de baja frecuencia de 12dB por octava
para prevenir la saturación de los
transformadores de 70V del altavoz. Esto reduce
la deformación y evita la sobrecarga del
amplificador. El ajuste de 50 Hz usualmente
funciona bien con transformadores de
amplificadores de alta calidad. El ajuste de 75
Hz funciona bien con altavoces y
transformadores de calidad parlante.

Modo puenteado - Los
conmutadores 4, 5, 6, 7 y 8
están todos ajustados en
la posición DERECHA.
El conmutador 10 está
ajustado en la posición
IZQUIERDA.

Filtro de baja frecuencia­Los conmutadores 2 y 3
controlan CH1. Los
conmutadores 8 y 9
controlan CH2.
Los conmutadores 3 y 8
ENCIENDEN o APAGAN el
filtro LF. Los
conmutadores 2 y 9
seleccionan 30Hz ó 70 Hz.

Modo puenteado Ti - Los
conmutadores 3, 4, 5, 6,
7 y 8 están todos
ajustados en la posición
DERECHA.
El conmutador 10 está
ajustado en la posición
IZQUIERDA.

Filtro de baja frecuencia Ti­El conmutador 2 controla
CH1.
El conmutador 9 controla
CH2.
Los conmutadores 2 y 9
seleccionan 50Hz ó 75 Hz.

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Entradas

Cada canal tiene balance de audio XLR y una entrada al bloque
de terminales. La impedancia de entrada es de 20k ohmios
balanceada o 10k ohmios no balanceada.

Se recomiendan conexiones balanceadas para un menor
zumbido e interferencia de la CA, especialmente en tramos
largos de cable. Las conexiones no balanceadas pueden ser
adecuadas para tramos cortos de cable. La impedancia de la
fuente de la señal debe ser menor de 600 ohmios. Si el DataPort
se está usando para proporcionar señales de entrada al
amplificador, no conecte las señales de entrada al XLR ni a los
conectadores del bloque de terminales.

Si es necesaria una conexión no balanceada, conecte el
conductor de señal a la pata + del conectador y el blindaje a la
pata de conexión a tierra. Conecte un puente entre la pata de
conexión a tierra y la pata -.

Salidas directas de baja impedancia

Las conexiones directas a las salidas de baja impedancia se
muestran en la parte posterior del chasis, a la derecha de los
terminales de salida. Note detenidamente las marcas de
polaridad, que están configuradas para facilitar las conexiones
del modo puenteado.

Modo estéreo y paralelo: Conecte cada carga del altavoz a su
propio canal del amplificador, como se muestra en la etiqueta
del chasis que se encuentra a la derecha de los terminales. Los
conmutadores de configuración de modo, página 5, deben
ajustarse en modo estéreo o paralelo.

Entradas balanceadas del bloque de terminales: quite 1/4 de pulgada (6 mm) de aislamiento del cable y conecte la clavija como se muestra. Asegúrese de apretar firmemente los tornillos.

Entradas no balanceadas del bloque de terminales: quite 1/4 de pulgada de aislamiento y conecte la clavija como se muestra La pata central debe estar conectada con la pata de blindaje como se muestra. Asegúrese de apretar firmemente los tornillos.

Entradas XLR balanceadas: conecte a la clavija como se muestra.

Entradas XLR no balanceadas: conecte a la clavija como se muestra. La pata - debe estar conectada con la pata de blindaje como se muestra.

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Modo puenteado: El modo puenteado configura el

amplificador para que excite una sola carga de alta potencia del
altavoz. Consulte la página 5 para ajustar los conmutadores de
modo puenteado. Conecte las cargas como se muestra en las
etiquetas a la derecha de los terminales. Use los dos terminales
centrales marcados como BRIDGE MONO (MONOPUENTEADO).
4 ohmios es la impedancia mínima en el modo puenteado. Use
los canales de modo estéreo o paralelo para excitar cargas de 2
ohmios.

PRECAUCIONES CON EL MODO PUENTEADO: ¡No
use cargas menores de 4 ohmios en el modo
puenteado! 4 ohmios es la impedancia mínima
para la operación en modo puenteado.

¡ADVERTENCIA SOBRE LA SEGURIDAD DE LOS
TERMINALES DE SALIDA! No toque los
terminales de salida mientras el amplificador
está encendido. Asegúrese de que todas las
conexiones con el amplificador estén apagadas.
¡Riesgo de energía peligrosa!

¡ADVERTENCIA! ¡Riesgo de energía peligrosa!
Se debe usar cableado Clase 2.

¡ADVERTENCIA DE ISA 1350!: Use el alambre
adecuado para el altavoz. Se debe usar cableado
Clase 2. Para el modo monopuenteado se debe
usar cableado Clase 3.

Salidas directas de baja impedancia: Conecte los altavoces como se muestra en la etiqueta que se encuentra junto a los terminales de salida. ¡Note la conexión monopuenteada (terminales centrales) y la polaridad!

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