QSC ISA 300T - Manuals

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...

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...

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 ...

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 ...

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...

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...

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.

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...

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...

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...

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...

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...

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...

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...

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!

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...

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...

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...

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...

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...

APPLICATIONS: MULTIPLE LOW IMPEDANCE LOADS IN SERIES (all models)

APPLICATIONS: MULTIPLE LOW IMPEDANCE LOADS IN PARALLEL (all models)

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...

• 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...

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...

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...

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...

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.