Page 2 - RISK OF ELECTRIC SHOCK; IMPORTANT SAFETY PRECAUTIONS; This amplifier has a serial number located on the rear panel.
CAUTION: TO REDUCE THE RISK OF ELECTRICSHOCK, DO NOT REMOVE THE COVER. NO USER-SERVICEABLE PARTS INSIDE. REFER SERVICINGTO QUALIFIED PERSONNEL. FCC INTERFERENCE STATEMENT NOTE: This equipment has been tested and found to comply with the limits for a class B digital device, pursuant to part15 of the ...
Page 3 - TABLE OF CONTENTS
INTRODUCTION: ISA Series Overview .......................................................................................4Front Panel Illustration .........................................................................................4Rear Panel Illustrations .........................................
Page 4 - FRONT PANEL; The QSC shipping box should contain:; INTRODUCTION AND FRONT PANEL ILLUSTRATION
FRONT PANEL (all models) Thank you for the purchase of your new ISA amplifier. To getthe most out of your amplifier, review this manual carefully. Theinstallation, connection and operation sections provide usefulguidelines to get you up and running quickly and correctly. The QSC shipping box should ...
Page 6 - POWER SWITCH, COOLING AIR VENTS; still fails to illuminate,
The front panel of ISA series amplifiers is tailored for installedsound. The power switch is the only front panel control; gaincontrols are located on the rear panel to minimize controltampering. LED indicators are provided for power, input signaland to warn of clipping. If the POWER LED fails to il...
Page 7 - Occasional illumination:
FEATURES & SETUP- LED INDICATORS CLIP : red LED that illuminates when the amplifier clips. Normal indication: illumination briefly at extreme output power peaks. Occasional clipping (once brieflyevery few seconds) when operation at high powerlevels is normal. At power-on, the clip LEDs may brief...
Page 8 - GAIN CONTROLS & INPUT JACKS; MAXIMUM VOLTAGE GAIN BY MODEL
FEATURES & SETUP- GAIN CONTROLS & INPUT JACKS GAIN CONTROLS- The Gain controls are located on the rear panel to minimizecontrol tampering after installation. When viewing the amplifierfrom the rear, they are on the left end, top and bottom, as shownin the illustration to the right. The Gain ...
Page 9 - DATAPORT V2
DATAPORT V2- What It Is- The DataPort V2 is used for connection to optional QSC DataPort accessories. DataPort accessory devices canprovide remote cinema monitoring, DSP, filter and crossoverfunctions. The “V2” DataPort connection is a “version-2” of QSC’s originalDataPort. It has a reduced feature ...
Page 10 - STEREO & PARALLEL OPERATING MODES; When to use PARALLEL input configuration:
FEATURES & SETUP- STEREO & PARALLEL OPERATING MODES PARALLEL: The channel 1 and channel 2 inputs are connected together,applying a single input signal to both channels of the amplifier. A signal into any input jack will drive both channels. Eachchannel's low frequency filtering, clip limitin...
Page 11 - STEREO & PARALLEL MODE DIP SWITCH SETTINGS; Refer to the switch setting keys for each mode, to the right.; SETTING THE DIP SWITCHES FOR STEREO OR PARALLEL MODE- “T” models; Refer to the switch setting keys for each mode, at the right.; SETTING THE DIP SWITCHES FOR STEREO OR PARALLEL MODE- “non-T” models
FEATURES & SETUP- STEREO & PARALLEL MODE DIP SWITCH SETTINGS ISA 280, ISA 450, ISA 750: Refer to the switch setting keys for each mode, to the right. These keys are printed on the amplifier’s rear panel for easyreference when you are behind the equipment rack. SETTING THE DIP SWITCHES FOR ST...
Page 12 - BRIDGE OPERATING MODE & DIP SWITCH SETTINGS; BRIDGE MODE OPERATION-
FEATURES & SETUP- BRIDGE OPERATING MODE & DIP SWITCH SETTINGS BRIDGE MODE OPERATION- Note that speaker connection for bridge mono mode isdifferent than other modes. See section on Connections:Outputs for proper bridge mode output connections.
Page 13 - LOW FREQUENCY FILTER & DIP SWITCH SETTINGS; SETTING THE FILTER DIP SWITCHES-; The low frequency filter
FEATURES & SETUP- LOW FREQUENCY FILTER & DIP SWITCH SETTINGS SETTING THE FILTER DIP SWITCHES- 1- Set switch #3 and #8 to the on or off position as desired. 2- Select the desired roll-off frequency at switch #2 and #9. 3- If filter off is selected, the frequency selection has no effect. If op...
Page 15 - CLIP LIMITER & DIP SWITCH SETTINGS
FEATURES & SETUP- CLIP LIMITER & DIP SWITCH SETTINGS CAUTION: Clip limiting reduces extreme overdrive peaks, allowing a higher average signal level without audibledistortion. However, increasing the gain with the clip limiter engaged, until clipping is again audible, can doublethe average ou...
Page 16 - RACK MOUNTING AND MOUNTING DIMENSIONS; Securing the Front Ears to the Rack Rails; ISA Rack Mounting; The amplifier is first; Supporting the Rear of the Amplifier
INSTALLATION: RACK MOUNTING AND MOUNTING DIMENSIONS Securing the Front Ears to the Rack Rails Use four screws and washers when mounting theISA amplifier to the front rails. Support the weightof the amplifier while securing it to the rails toavoid bending or distorting the front rack mountears. ISA R...
Page 17 - COOLING REQUIREMENTS & AC MAINS; Air flow in QSC amplifiers; and may damage the amplifier.; The AC line cord; equivalent. Insure that the wire gauge of the cord is; Use the best possible connection to the AC power source.; Avoid extension cords as they will cause some
INSTALLATION: COOLING REQUIREMENTS & AC MAINS FAN COOLING- Keep the front and rear vents clear to allow full air flow. Make sure that plenty of coolair can enter the rack, especially if there are other units which exhaust hot air into it. Connecting to the wrong line voltage is dangerous and may...
Page 19 - How to Connect to the DataPort V2:; switch to turn the amp on and off.; If it is an accessory that mounts directly; to the rear of the amplifier, orient the accessory correctly; If the accessory attaches with a QSC DataPort cable; , orient the HD-15 male plug correctly with
CONNECTIONS: INPUTS- DATAPORT V2 The ISA series of amplifiers come with a DataPort V2 connectorthat may be used for connecting to accessory QSC DataPortdevices. The V2 (or version 2) DataPort does not have the fullcapability of the standard DataPort. The DataPort V2 must beconnected to a QSC DataPor...
Page 20 - USING THE SCREW TERMINAL CONNECTIONS; ) Protective cover in the open position.; STACKING OF TONGUE TERMINALS-
CONNECTIONS: OUTPUTS- USING THE SCREW TERMINAL CONNECTIONS GENERAL- The screw terminal output connections areprotected by a hinged plastic cover. To make connections to the screw terminals,you will need to swing the cover door open.Gently pry the cover with your finger tips onthe side that has the w...
Page 21 - BRIDGE MODE PRECAUTIONS:; Do not place speaker cables next to; Direct Low Impedance Output Connections-; Use these terminals for 2 through 16 ohm loads.; STEREO or PARALLEL Mode:; Connect each
CONNECTIONS: OUTPUTS- DIRECT LOW IMPEDANCE (LO-Z) BRIDGE MODE PRECAUTIONS: Do Not Use 2 ohm Loads in Bridge Mono Mode! 4 ohms is the minimum impedance for bridge mono operation! This mode puts a high demand on the amplifier and speaker. Excessive clipping may cause protective muting orspeaker damage...
Page 23 - OUTPUT TERMINAL SAFETY WARNING!
CONNECTIONS: OUTPUTS- DISTRIBUTED HIGH IMPEDANCE (HI-Z) , BRIDGE MODE 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!
Page 24 - POWER SHARING BETWEEN HIGH & LOW IMPEDANCE OUTPUTS
CONNECTIONS: POWER SHARING BETWEEN HIGH & LOW IMPEDANCE OUTPUTS The ISA 300T, ISA 500T and ISA 800T models are equippedwith autotransformer-coupled, high impedance (High-Z)outputs. They are also equipped with low impedance (Low-Z) “direct” outputs. The high impedance outputs are notisolated. The...
Page 25 - SECURING OUTPUT WIRING TO CHASSIS
Page 26 - AC POWER SWITCH, LED INDICATORS, GAIN CONTROLS; NORMAL OPERATING LEVELS; A NOTE ON SOUND PRESSURE LEVELS-; If exposure is at or greater than the; GAIN CONTROLS
OPERATION: AC POWER SWITCH, LED INDICATORS, GAIN CONTROLS NORMAL OPERATING LEVELS The amplifier’s protective muting system guards againstexcessive internal temperatures. With normal ventilation and 4to 8 ohm loads, the amplifier will handle any signal level,including overdrive. Lower load impedances...
Page 27 - GENERAL APPLICATION INFORMATION; General ISA Application Information-
APPLICATIONS: GENERAL APPLICATION INFORMATION The ISA 280, ISA 450 and ISA 750 amplifiers are optimized for directly driving low impedance loads. Low impedance (Lo-Z) loads arethose loads between 2 and 16 ohms. These models are not suitable for driving “constant voltage” 70V lines. These low impedan...
Page 28 - LOW FREQUENCY FILTERING & DISTRIBUTED OUTPUTS; Low frequency; Low Frequency Filtering for 70-100V Systems-; Distributed Output Application Examples-
APPLICATIONS: LOW FREQUENCY FILTERING & DISTRIBUTED OUTPUTS The low frequency filtering is another difference in the characteristics of the “non-T” and the “T” amplifiers. Because transformers andother magnetic devices are prone to low frequency “misbehavior” (called saturation) , the autotransf...
Page 29 - DISTRIBUTED OUTPUTS
100 Volt, two-zone example: The illustration to the right shows a typicaltwo-zone 100 volt system. When using 100volt speaker loads, make sure that connec-tions to the amplifier are made to the 100 voltoutput terminals. If using the ISA 300T, 300 watts per channel(zone) can be delivered. Make sure t...
Page 30 - MULTIPLE LOW IMPEDANCE LOADS IN SERIES (all models)
APPLICATIONS: MULTIPLE LOW IMPEDANCE LOADS IN SERIES (all models)
Page 31 - MULTIPLE LOW IMPEDANCE LOADS IN PARALLEL (all models)
APPLICATIONS: MULTIPLE LOW IMPEDANCE LOADS IN PARALLEL (all models)
Page 32 - will not work with the ISA series of amplifiers.
32 The DSP-3 Digital Signal Processing Module provides compressor-limiter, multiple parametric filters, high- and low-pass filters, shelf filters, multiple delays, polarity reversal, muting and attenuation. These features and more come packed into a small module thatinterfaces with the DataPort V2 c...
Page 33 - INDICATION: CLIP LED FLASHING; • If the red clip; NO SOUND; • INDICATION: POWER LED INDICATOR NOT ILLUMINATED; amplifier serviced by a qualified technician.; INDICATION: SIGNAL LEDS RESPONDING TO SIGNAL LEVEL; The amplifier is in protective muting.
• INDICATION: CLIP LED FLASHING • If the red clip indicator flashes when signal is applied, the amplifier output may be shorted. Check that the speaker cable connec- tions are tight and reliable at both ends. Check the speaker cables for stray strands or breaks in the insulation. Trim off all looses...
Page 34 - PROBLEM: DISTORTED SOUND
PROBLEM: DISTORTED SOUND Magnetic field from power supplies in equipment can induce hum into cabling that is located in the field. If hum is a problem, try relocating cabling so that is away from power supplies, transformers and other magnetic field producing devices. TROUBLESHOOTING: DISTORTION, NO...
Page 35 - SPECIFICATIONS
SPECIFICATIONS ISA 280 ISA 450 ISA 750 OUTPUT POWER in watts FTC: 8 ohms per channel (20-20k Hz., 0.1% THD) 185 260 450 4 ohms per channel (20-20k Hz., 0.1% THD) 280 425 650 EIA: 16 ohms (1 kHz., 0.1% THD, 1 channel driven) 100 140 250 8 ohms (1 kHz, 0.1% THD, 1 channel driven) 200 280 475 4 ohms (1...
Page 39 - WARRANTY; WARRANTY INFORMATION & HOW TO CONTACT QSC
Disclaimer QSC Audio Products, Inc. is not liable for any damage to speakers, amplifiers, or any other equipment that is caused by negligence or improper installation and/or use of the ISA amplifier. Product Warranty QSC guarantees the ISA amplifier to be free from defective material and/or workmans...
Page 40 - 675 MacArthur Boulevard Costa Mesa, California 92626 USA
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. ©2000 QSC Audio Products, Inc.
