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ISA 800T - R.S. Engineering and Manufacturing

1. Ensure proper polarity is maintained for all connections 25 Volt Stereo or Parallel Connection 70 volt lines OUTPUTS TO DISTRIBUTED LINES Connect one of the 70 volt lines to the CH1 terminals marked 70V Connect the other 70 volt line to the CH2 terminals marked 70V WARNING RISK OF HAZARDOUS ENERGY SEE OPERATION MANUAL CLASS 2 WIRING MAY BE USED FOR BRIDGED The 70V connection is between the ET T p 80 AND Ta 177 m i mar ings 70V Ensure proper polarity is maintained for all connections 70 Volt Stereo or Parallel Connection 100 volt lines Connect one of the 100 volt lines to the CH1 terminals marked 100V OUTPUTS TO DISTRIBUTED LINES E17 70V El p w p a ES E ni itv 100V Connect the other 100 volt line to the CH2 terminals marked 100V WARNING RISK OF HAZARDOUS ENERGY SEE OPERATION MANUAL CLASS 2 WIRING MAY BE USED FOR BRIDGEI MONO AND 100V DISTRIBUTED OUTPUTS CLASS 1 WIRING MUST BE USED The 100V connection is between the land markings Ensure proper polarity is maintained for all connections 100 Volt Stereo or Parallel Connection OUTPUT TERMINAL SAFETY WARNING Class 2 wiring may be used For Do not touch output terminals while amplifier power is on Make all bridged mono and 100V distributed connections with amplifier tur
2. te er er emm ere a 16 Mounting DIMENSIONS ia aiea Pr bee ot dre betae ss 16 Cooling REGUIFEMENTS 4 suan u enero ee tel ed ers 17 AG Mains AG ROWER uet cca tet aloes neos eo da ee ee beet ao raat chee 17 CONNECTIONS Inputs XLR and Terminal Block Input Jacks 18 Inputs DataPort V2 Connections and Notes 19 Outputs Using the Screw Terminal Connections 20 Outputs Direct Low Impedance 2 16 ohm loads 21 Outputs Distributed High Impedance T models 22 Power Sharing Between High and Low Impedance Outputs T models only 24 Securing Output Wiring to the Chassis sss 25 OPERATION Gain Ete te tete 26 AG PONGE SWILEN i o 26 Front Panel LED IndICaters ere rr ee 26 Normal Operating Levels ask 26 APPLICATIONS General Notes Distributed Line Principles 27 Low Frequency Filtering Distributed Output Examples 28 Multiple Low Impedance Loads in Series or Parallel Connections 30 DataPort V2 Application Information ccccccccsc
3. dB ATTEN 9 CHANNEL 2 How to Connect to the DataPort V2 If itis an accessory that mounts directly to the rear of the amplifier orient the accessory correctly and attach to the amplifier per the accessory s instructions If the accessory attaches with a OSC DataPort cable orient the HD 15 male plug correctly with the DataPort V2 socket on the amplifier it is D shaped and will fit only one way Push the plug onto the socket firmly and ensure it is seated properly Finger tighten the 2 retaining screws Do not over tighten Basic Operation Notes 1 The amplifier Gain controls will need to be set at their anticipated high level setting Use reduced level setting during setup amp test 2 Control of the audio level will be accomplished with the DataPort accessory device to which the amp is connected 3 No control of the amplifiers AC power will be possible via the DataPort V2 Use the amplifiers POWER switch to turn the amp on and off 4 See page 32 for additional DataPort V2 Application information block connectors The unused XLR or terminal block inputs may be used for daisy chaining the DataPort V2 input signal to other amplifiers The signal level available from the unused inputs will be about 10 dB lower than the signal applied at the DataPort V2 connector If using the DataPort V2 connection do not connect any inputs to the XLR or terminal 19 CONNECTIONS OUTPUTS USING THE SCREW TERMINAL CONNECTIONS GENE
4. When selecting speaker cable wire always use the largest wire size and shortest length of wire practical for any given installation Larger wire sizes and shorter lengths minimize power loss and degradation of damping factor Do not place speaker cables next to input wiring Direct Low Impedance Output Connections Use these terminals for 2 through 16 ohm loads IM DANCE OUTPUTS 70V 100V STEREO or PARALLEL Mode Connect each speaker cable to its respective channel s screw terminals Make sure speaker polarity is maintained Note that channel 1 and channel 2 connections have the positive terminal in different locations 70V 100V DIRECT LOW priis DUTPUTS CHI BRIDGE Mode Connect the one speaker cable to 20 the center screw terminals labeled BRIDGE MONO Make sure speaker polarity is maintained 2 ohm 70V loads are not usable in BRIDGE mode 100V 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 or speaker damage Ensure the speaker has a sufficient power rating Output voltages greater than 100 volts rms are available between the amplifier s bridged terminals CLASS 2 or A CLASS 1 wiring methods as specified in accordance with national NEC and local c
5. 13 2 cm tall 3 rack spaces 15 75 40 0 cm deep from front mounting rails including rear support ears 36 pounds 16 3 kg 36 pounds 16 3 kg 47 pounds 21 3 kg SPECIFICATIONS SUBJECT TO CHANGE WITHOUT NOTICE OUTPUT POWER in watts Low Impedance 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 Low Impedance 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 kHz 0 1 THD 1 channel driven 300 500 750 2 ohms 1 kHz 1 THD both channels driven 430 700 1200 Low Impedance Bridged Mono 16 ohms 20 20k Hz 0 1 THD 370 520 900 8 ohms 1 kHz 0 1 THD 600 900 1500 4 ohms 1 kHz 1 THD 830 1400 2400 Distributed High Impedance 70 volt 50 Hz 16 kHz 0 5 THD per channel 300 500 800 100 volt 300 500 800 140 volt bridge 600 1000 1600 200 volt bridge 600 1000 1600 DYNAMIC HEADROOM all models 2 dB at 4 ohms DISTORTION SMPTE IM all models LESS THAN 0 01 LESS THAN 0 01 LESS THAN 0 01 FREQUENCY RESPONSE all T models DIRECT OUTPUTS 3 dB at 50 Hz to 0 5 dB at 20 kHz at 10 dB below rated output power DISTRIBUTED OUTPUTS 50 Hz to 16 kHz 0 dB 3 dB DAMPING FACTOR all models Greater than gt 200 for 8 ohm load SIGNAL to NOISE unweighted 20 20k Hz 100 dB 100 dB 100 dB VOLTAGE GAIN gain control set to 0 dB 30 5 dB 33 4 X 33 0 d
6. FOR BRIDGED d NN AND 100V 2 Ur ID To Speaker Loads DISTRIBUTED OUTPUTS CLASS 1 WIRING MUST BE USED 25 OPERATION AC POWER SWITCH LED INDICATORS GAIN CONTROLS AC POWER SWITCH Before applying power check all connections and turn down the gain controls When the AC power is switched on the power indicator LED will light at half brightness and the fan will start The outputs are muted Then the power indicator fully illuminates and the amplifier unmutes The clip and signal LEDs will flash briefly When the clip LEDs go out the amplifier is ready After the amplifier has been powered up slowly increase the Gain settings for each channel and check for the proper operation of all speaker loads If you detect any problems with speakers or wiring turn the amplifier off correct the problem and try again Once the system has been tested adjust Gain levels as required GAIN CONTROLS The Gain controls are located on the rear panel of the amplifier as shown on page 6 The controls are detented 11 steps for repeatable adjustment Surrounding the Gain control the power attenuation level is shown in dB To operate the Gain control rotate the control s knob so that the desired level is achieved There is a detent in the knob to indicate its position NORMAL OPERATING LEVELS The amplifier s protectiv
7. zone can be delivered Make sure that the OUTPUTS TO DISTRIB D LINES total speaker power load on each channel does not exceed 300 watts E a 25V If using the ISA 500T or ISA 800T the per mes TOME channel power limit is 550 and 800 watts Eros xv respectively DU cud agis OUTPUT TERMINAL SAFETY WARNING Class 2 wiring may be used For bridged Do not touch output terminals while amplifier power is on Make mono and 100V distributed outputs all connections with amplifier turned off Risk of hazardous energy class 1 wiring must be used 28 APPLICATIONS DISTRIBUTED OUTPUTS 70 Volt two zone example ISA 300T ISA 500T ISA 800T The illustration to the right shows a typical two zone 70 volt system When using 70 volt speaker loads make sure that connections to the amplifier are made to the 70 volt output terminals ZONE 1 ZONE 2 E If using the ISA 300T 300 watts per channel El 3l zone can be delivered Make sure that the BEDV total speaker power load on each channel does not exceed 300 watts E El If using the ISA 500T or ISA 8007 the per channel power limit is 550 and 800 watts 2 respectively Tw ZONE 1 ZONE 2 100 Volt two zone example ISA 300T ISA 500T ISA 800T Dr t The illust
8. 800T MODE SWITCHES BRIDGE MONO 1 Switch 3 4 5 6 7 and 8 must all be switched to the right to operate in bridge mode USE CH1 INPUT CLIP LIM AND FILTERS USE CH1 GAIN CONTROL TOADJUSTLEVEL CH2 1 2 3 4 1 SWITCH OFF THE CH 2 RO A j BRIDGE BRIDGE CLIP LIMITER AND SET THE 7 a 2 Switch 10 should be switched to the left 50 that MONO OFF 7 MONO ON 7 iei marr oo 25S channel 2 s clip limiter is off Channel 1 s clip limiter 9 USETHE BRIDGE MONO 10 CLIP LIMITER ON 10 SPEAKER CONNECTION controls both channels in bridge mode MODE SWITCHES ISA 300T ISA 500T and ISA 800T models switches 3 4 5 7 and 8 must all be set to the right side position Switch 10 should be set to its left side position See chart above 12 FEATURES amp SETUP LOW FREQUENCY FILTER amp DIP SWITCH SETTINGS Generally match the frequency selection to your speaker s low frequency capability This improves speaker performance by limiting subaudio cone movement making more power available for the speaker s rated frequency range Unless you already have filtering in the signal path preceeding the amplifier use the low frequency filter to protect your speakers from cone over excursion caused by frequencies below the speakers limits The speakers documentation will specify the low frequency limit Differences Between T amp non T Models ISA 280 ISA 450 and ISA 750 s have defeatable low frequency filters with sele
9. V2 is used for connection to optional OSC DataPort accessories DataPort accessory devices can provide remote cinema monitoring DSP filter and crossover functions The V2 DataPort connection is a version 2 of OSC s original DataPort It has a reduced feature set from the original while maintaining essential amplifier monitoring capability t does not supply 15 VDC power required by some DataPort accessories What Can Connect to the DataPort V2 Consult your QSC representative for up to date accessory compatibility OSC has several DataPort based accessories available like the DSP 3 Digital Signal Processing Module XC 3 Crossover SF 3 Subwoofer Filter LF 3 Low Frequency Filter DCM Crossovers amp Monitors page 32 has additional information NOTE The DataPort V2 can only supply a maximum current of 40 mA Some accessories such as the DSP 3 require more than 40 mA to operate Use an external power supply with such accessories Daisy Chaining to Other Amplifiers While Using the DataPort V2 for Input Signals If the incoming audio input signal is through the DataPort V2 the XLR and terminal block connectors can be used to daisy chain the input signal to other equipment The signal at these connectors will be about 10 dB lower in voltage than the incoming DataPort V2 signal The illustration to the right shows the basic daisy chain hookup Note that the XLR connections may also be used for daisy chaining the au
10. cable for remote equipment interconnect Computer data cables although similar in appearance will not function properly and may damage your equipment Contact your QSC dealer for details and for OSC accessories This listing is current at time of writing for up to date accessory information contact your OSC representative 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 that interfaces with the DataPort V2 connector on the rear of your ISA amplifier Not all features of the DSP 3 are available via the Version 2 DataPort consult your OSC sales professional for full details The accessory remote power supply must be used to supply DC power to the DSP 3 accessory module power is NOT provided by the ISA amplifiers The XC 3 Crossover provides a built in active two way crossover It features fourth order Linkwitz Riley filters with SIP selectable crossover frequencies DIP switch control of high frequency equalization for CD horn equalization SIP selectable subsonic filter and SIP selectable all pass low frequency delay The SF 3 Subwoofer Filter is used primarily as an adjustable bandpass filter for subwoofers The filter may be configured for a flat roll off or a boosted response to equalize certain subwoofer models with step down tuning
11. clip limiter low frequency filter input zycGorcmpd cR E ae gt Amplifier 2 CH2 input connectors may be used How to use PARALLEL mode to daisy chain the input signal to additional amplifiers 1 Set the DIP switches for PARALLEL mode see facing page 2 Connect the one input signal to any one input connector PARALLEL MODE OPERATION 3 Connect the two speakers one to CH1 s output terminals one to CH2 s output terminals 10 FEATURES amp SETUP STEREO amp PARALLEL MODE DIP SWITCH SETTINGS SETTING THE DIP SWITCHES FOR STEREO OR PARALLEL MODE non T models MODE SWITCHES STEREO PARALLEL ISA 280 ISA 450 ISA 750 1 MODE INPUTS gt 2 1 1 Refer to the switch setting keys for each mode to the right 3 2 2 I PARALLEL 3 3 bes 5 4 These keys are printed on the amplifier s rear panel for easy BRIDGE 6 BRIDGE 5 5 reference when you are behind the equipment rack MONO OFF 7 ON STEREO Set switch 4 5 6 and 7 to the L left 10 10 10 MODE SWITCHES PARALLEL Mode Set switch 4 and 5 to the TA ER ee ee right set switch 76 and 77 to the left d s icd SETTING THE DIP SWITCHES FOR STEREO OR PARALLEL MODE T models MODE SWITCHES ISA 300T ISA 500T and ISA 800T STEREO PARALLEL 2 MODE INPUTS Refer to the switch setting keys for each mode at the right 3
12. induce hum into cabling that is located in the field If common entry point for hum Use top quality cabling Another common source of magnetic fields are wall warts or pluggable transformers keep input wiring away from them hum is a problem try relocating cabling so that is away from power supplies transformers and other magnetic field producing devices 34 OUTPUT POWER in watts FTC 8 ohms per channel 20 20k Hz 0 196 THD 185 260 450 4 ohms per channel 20 20k Hz 0 196 THD 280 425 650 FIA 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 kHz 0 1 THD 1 channel driven 300 500 750 2 ohms 1 kHz 1 THD both channels driven 430 700 1200 Bridged Mono 16 ohms 20 20k Hz 0 1 THD 370 520 900 8 ohms 1 kHz 0 1 THD 600 900 1500 4 ohms 1 kHz 1 THD 830 1400 2400 DYNAMIC HEADROOM all models 2 dB at 4 ohms DISTORTION SMPTE IM all models LESS THAN 0 01 LESS THAN 0 01 LESS THAN 0 01 FREQUENCY RESPONSE all models 20 Hz to 20 kHz 0 1 dB at 10 dB below rated output power 3 dB points 5 Hz and 50 kHz DAMPING FACTOR all models Greater than gt 200 for 8 ohm load SIGNAL to NOISE unweighted 20 20k Hz 100 dB 100 dB 100 dB VOLTAGE GAIN gain control set to 0 dB 30 5 dB 33 4 X 33 0 dB 44 7 X 35 0 dB 56 2 X INPUT SENSITIVITY for rated power into 8 ohms INPUT CLIPPING Vrms all models INPUT IMPEDANCE all mod
13. load and so on If any of the speakers in a series connected branch of a system fails the signal is prevented from flowing through any of the loads no sound Total impedance for series connections is the sum of each of the impedances in the chain see illustration below Series connection schemes are usually used with raw speakers not often with speaker cabinets for wiring conve nience The exposed speaker connections make this method easy for small strings of speakers in one area Most PA type SERIES LO Z LOADS Zeq is the abbreviation for equivalent impedance and means the impedance atthe two connection points T 2 series loads Impedance of speakers Note Impedance has a phase angle also This is typically neglected in basic speaker calculations 30 p 3series loads Formula Zeq Z1 Z2 Zeq Z1 Z2 Z3 Zeq 2 2 4ohms Zeq 2 2 2 65ohms 4 ohm Zeq 4 4 8ohms Zeq 4 4 4 12 ohms speaker cabinets are NOT wired for series connection ability consult your speaker s documentation for connection information It is not recommended to connect speakers of different imped ances in series because power will be divided unequally between them If you are experienced with mixing and matching speaker loads of varying impedances no damage to the amplifier will result as long as the total impedance is within 2 to 16 ohms per channel Below are examples of series connections for 2 4 and 8 ohm speaker loads Ser
14. mono PROBLEM HISS Unplug the input cables to the amplifier If the hiss goes away then the problem is with the equipment or cables leading to the amplifier e f the hiss is present with no audio input cables connected check that the AC line cord is properly grounded at its connection to the line If the ground connection is OK and the hiss continues with no input cables connected then the amplifier requires servicing o keep the normal noise floor low operate the primary signal source at full level without clipping and avoid boosting the signal further between the source and the amplifier PROBLEM SQUEALS AND FEEDBACK Microphone feedback should be controlled with mixer controls If noise continues to build up with zero mic gain there is a serious fault in the signal processors or cables Working in succession from the signal source towards the amplifier check each device in the signal path by reducing its gain or unplugging it PROBLEM HUM Use a common AC ground connection for all audio equipment e Check the input cables for broken ground shield connection Use balanced connections for the entire signal chain e The design of the amplifier eliminates internal hum fields but external transformers or other magnetic devices may cause hum Move cabling and signal sources to identify hot spots in the Magnetic field from power supplies in equipment can system then avoid those spots Cables with faulty shielding are a
15. output currents from the amplifier and should be approached with some caution If operated at reasonable power levels similar to 1 8 rated power with pink noise test signal with 2 ohm loads the amplifier will perform exceptionally At high power with chest pounding bass program material excessive clipping with 2 ohm loads may cause excessive heat in the amplifier and trigger thermal shutdown The ISA 300T ISA 500T and ISA 800T amplifiers have the additional capability of driving constant voltage distributed audio lines of 25 70 and 100 volts The outputs are autotransformer coupled they are not fully isolated These autotransformer equipped models also have low impedance outputs for added flexibility of system design and configuration The total available output power from each channel can be shared between the direct low impedance outputs and the autotransformer coupled high impedance outputs These high impedance capability models are referred to collectively as the T models Distributed Line Principles T models only Distributed lines are the easiest and most reliable way of distributing audio to many low power speaker loads located over a wide area It is easy to use because all the loads are connected in parallel across a pair of wires there is normally no need to put speakers in series or series parallel arrangements to meet specific impedance requirements It is reliable because the parallel connection scheme makes it so that if any one
16. speaker fails the remaining speakers will continue to operate Additionally since the operating voltage of distributed lines is fairly high the current through the line is kept fairly small this minimizes resistive losses in the wiring Distributed line systems are usually referred to by their nominal operating voltage with 25 70 and 100 volt systems being the most common The main difference with the various operating voltages will be the type of matching transformer on the speaker assembly In the illustration below the 70 volt transformer is connected to the 70 volt output terminals of channel 2 of the amplifier The input to the transformer may be connected to different taps that determine the nominal power that will be delivered to the speaker The example shows taps available for 2 5 5 10 and 20 watts with 10 watts selected Some transformers have the capability of matching the distributed line to several speaker impedances If this is the case in your system ensure that the speaker is connected to the tap that matches its impedance 70 volt systems are common in North America while 100 volt systems are more common in Europe 25 volt systems are typically older commercial intercom type components being maintained with new amplifiers The example below shows a 70 volt line with one speaker load attached Most distributed lines will have many speakers connected in parallel across the line To estimate the power handling requirements for a lin
17. to engage or disable the clip limiter channel 2 s clip limiter must be switched off 1 Set channel 2 s clip limiter switch to the off position This is switch 10 2 Set channel 1 s clip limiter switch on or off as desired This is switch 1 CAUTION Clip limiting reduces extreme overdrive peaks allowing a higher average signal level without audible In BRIDGE mode Channel 25 clip limiter must be set to the off position to avoid any interaction distortion However increasing the gain with the clip limiter engaged until clipping is again audible can double the average output power Be careful notto exceed the power rating of your speakers 15 INSTALLATION RACK MOUNTING AND MOUNTING DIMENSIONS NOTE Rack mounting of amplifier is optional Securing the Front Ears to the Rack Rails Amplifiers are inherently heavy It is Use four screws and washers when mounting the highly recommended that you have an ISA amplifier to the front rails Support the weight assistant support the amplifier during of the amplifier while securing it to the rails to rack installation to avoid injury avoid bending or distorting the front rack mount ears 15 90 inch gt nc 15 75 inch 7 14 75 inch k d AKT ias 17 40 inch y 2 25 inch T T oo fi gt a including screw heads 0 40 inch from back edge to centerline of holes hole size 0 25 x 0 47 3 00 inch 2 25 inch gt 2 60 inch from bottom of chassis to center
18. usable outputs They are also equipped with low impedance Low Model Output Power Output is 16 ohms 8 ohms 4 ohms 2 ohms Z direct outputs The high impedance outputs are not isolated lt 60 watts yes yes 60 to 150 watts yes caution 150 to 240 watts caution no The unique feature of the T model outputs is that you can 5240 watts a ie connect loads to the high impedance AND low impedance outputs for maximum system flexibility If the total output ISA 5007 500 Watts 0 watts yes yes power of a channel s high impedance connections does not 7 dus d exceed 2096 of maximum rated power then any of the rated T T low impedance load values can be connected at the low impedance terminals For applications where the high ISA 800T 800 Watts lt 160 watts yes yes impedance output power is 20 5096 then 8 or 16 ohm 180 to 400 watts yes caution loads on the low impedance output is OK If the high JUDA DAD E 2640 watts no no impedance output power is 50 to 8096 of rated power then 16 ohm loads are OK If the total output of a channels high Power sharing between Direct Lo Z and Distributed Hi Z impedance connections exceeds 80 of that channel s Outputs Acceptable Low Z loads as a function of High Z output maximum rated power then DO NOT USE the low imped power NOTE Caution advisory means that this load impedance ance outputs The following chart is a us
19. B 44 7 X 35 0 dB 56 2 X INPUT SENSITIVITY for rated power into 8 ohms 43 43 dBu 1 15 Vrms 42 81 dBu 1 07 Vrms 42 81 dBu 1 07 Vrms INPUT CLIPPING Vrms all models 422 dBu INPUT IMPEDANCE all models 10k ohms unbalanced 20k ohms balanced 37 AMPLIFIER PROTECTION Full short circuit open circuit thermal ultrasonic and RF protection Stable into reactive or mismatched loads COOLING Continuously variable speed fan back to front air flow INDICATORS Front Panel POWER LED green 2 each SIGNAL green and CLIP red LEDs CONNECTORS Input 2 XLR 2 terminal block euro or Phoenix and 1 0SC DataPort V2 connector Output screw terminal barrier strip LOAD PROTECTION Turn on turn off muting Turn on turn off muting Turn on turn off muting AC coupling AC coupling Triac crowbar Clip limiting Clip limiting Clip Limiting OUTPUT CIRCUIT TYPE AB AB Class H POWER REQUIREMENTS all models CURRENT CONSUMPTION 120 VAC typical both channels driven in Amperes Idle 1 8 power 8 ohms 1 8 power 4 ohms 1 8 power 2 ohms 1 8 power 70V or 100V SEE SERIAL NUMBER LABEL ON REAR PANEL FOR THE SPECIFIED OPERATING VOLTAGE 0 3 0 4 0 5 2 6 3 5 4 5 41 5 9 7 0 6 2 91 10 3 5 5 6 9 8 5 NOTE 1 8 power is representative of current draw with typical music program material with occasional clipping Pink noise CONTROLS all models DIMENSIONS all models WEIGHT all models kg 38 Front AC POWER switch Bac
20. B ISA 300T B ISA 500T ISA 800T ISA Series B ISA 280 Installed B ISA 450 Sound B ISA 750 Amplifiers User Manual ISA Audio Power Amplifiers TD 000093 00 rev C IMPORTANT SAFETY PRECAUTIONS amp EXPLANATION OF SYMBOLS CAUTION TO REDUCE THE RISK OF ELECTRIC SHOCK DO NOT REMOVE THE COVER NO USER RISK OF ELECTRIC SHOCK SERVICEABLE PARTS INSIDE REFER SERVICING DO NOT OPEN 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 all ISA amplifiers 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 seria
21. CED N 10 0 dB ATTEN oS 0 CHANNEL2 balanced connection g jumper shield Terminal block unbalanced connections 18 Unbalanced inputs Connect the conductors to the connector as shown Make sure that the unused side of the balanced input is connected to ground as shown XLR input pinout unbalanced pin2 Jumper pin 1 to 3 jumper pin1 to pin 3 4 pint XLR unbalanced connection CONNECTIONS INPUTS DATAPORT V2 The ISA series of amplifiers come with a DataPort V2 connector that may be used for connecting to accessory OSC DataPort devices The V2 or version 2 DataPort does not have the full capability of the standard DataPort The DataPort V2 must be connected to a OSC DataPort product with a QSC DataPort cable similar looking computer data cables will not work and could damage your OSC equipment The DataPort V2 connection will supply the input signals to the amplifier If using the DataPort V2 connection do not apply inputs to the XLR or terminal block connectors If the ISA amplifier is being used in a system monitored through T a QSC cinema monitor or other QSC DataPort product the following amplifier information will be provided by the amplifier DataPort V2 10 CHANNEL 1 STN dB ATTEN Sco INPUT IMPEDANCE 20K BALANCED CH1 and CH2 output voltage Amplifier AC power status on or off
22. ER 75 Hz FILTER 10 ch2 MODE SWITCHES ISA 300T ISA 500T and ISA 800T models frequency selection is 50 and 75 hertz Low frequency filter is always active and can not be defeated turned off 13 FEATURES amp SETUP FREQUENCY RESPONSE CURVES Frequency response curve for ISA 280 ISA 450 ISA 750 1 O Filter OFF Ac u t E p S o0 u CS H t 3 8 z N xs a Rm d B 2 B 4L 5 6L 20 50 100 200 500 1k 2k 5k 10k 20k Frequency Hz Frequency response curve for ISA 300T ISA 500T ISA 800T Note There is no Filter OFF selection on models 1 0 1L u L t E p L t Lj d C Ss B 4C 2 3 o 5 N s 18 t 6L 20 50 100 200 500 1k 2k 5k 10k 20k 14 Frequency Hz FEATURES amp SETUP CLIP LIMITER amp DIP SWITCH SETTINGS When the audio input signal drives the amplifier s output circuit beyond its power capability the amplifier clips and flattens the peaks of the waveform This flattening is what we hear as distortion during the clipping event MODE SWITCHES Clipping for short periods can be harmless Clipping for extended 1 oe OFF E ON periods can easily damage high frequency drivers tweeters i horns Low
23. HES Piten 1 1 Hi 70 Hz 2 30 FILTER 70 Hz FILTER S 30 Hz FILTER FILTER oo 3 FILTER OFF FILTER ON FILTER OFF 4 4 5 6 7 zm 7 FILTER ON S7 FILTER OFF FILTER ON 8 FILTER OFF 70 Hz FILTER SE 30 Hz FILTER HA 70 9 30Hz FILTER cha LJ 10 10 MODE SWITCHES ISA 280 ISA 450 and ISA 750 models frequency selection is 30 and 70 hertz Low frequency filter can be switched on or off with switches 3 and 8 2 Channel 1 s filter settings and clip limiter determine amplifier behavior Set channel 1 s low frequency filter on off switch frequency selection switch and clip limiter as desired ISA 300T ISA 500T and ISA 800T If operating in STEREO or PARALLEL MODE 1 Select the desired roll off frequency 50 or 75 hertz at switch 2 and 9 Each channel can be set independently If operating in BRIDGE MODE 1 Select the desired roll off frequency at switch 2 Setting of switch 9 is ignored To Prevent Output Transformer Saturation The 50 Hz filter setting prevents transformer saturation for normal unclipped program levels If heavy clipping is possible use the 75 Hz setting for extra protection See Low Frequency Filtering for 70 100V Systems page 28 MODE SWITCHES FILTERS en 1 TS Hz FILTER 50 Hz FILTER 5 2 50 Hz FILTER Hz FILTER 9 50 Hz FILT
24. ISA 750 800T Gain Output Power per ch 8 Ohm Load The attenuation level markings around the Gain controls are Setting MODEL 280 450 750 300T 500T 800T power levels not voltage To have an idea of the approximate 0 dB 185 260 450 185 260 450 Watts output power the table at left provides the output power by E a ra watts model as a function of the Gain setting The data provided is per si atts TER 3 317 3 4 7 IMS channel power for an 8 ohm load input fully driven 25 dB 0 6 08 14 06 08 14 Watts dB 0 0 0 0 0 0 Watts INPUTS WHERE THEY ARE The ISA series of amplifiers are equipped with XLR and terminal block connectors Input impedance is 20k ohm balanced 10k r ohm unbalanced The proper termination and connection u TI information is provided in the CONNECTIONS section of this CO ON manual Unused input connections may be used to daisy chain the input to additional amplifiers AING XLR CONNECTORS lt Additionally a DataPort V2 connector is provided for users of Aud QSC DataPort products The DataPort V2 can be used to provide input signals to the amplifier and to monitor the amplifier with the appropriate OSC DataPort product See the following section for DataPort V2 information 25 dB ATTEN oS 0 CHANNEL2 FEATURES amp SETUP DATAPORT v2 DATAPORT V2 What It Is The DataPort
25. RAL The screw terminal output connections are protected 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 on the side that has the wire openings After the door is open loosen the screws for the terminals you are planning to use Do this by rotating the screw counter clockwise with an appropriate screwdriver After loosening the screws slide the tongue terminals under the head of the screw and seat the terminal firmly against the screw 1 Protective cover closed covering the screw terminals Tighten the screw by rotating it clockwise with an appropriate screwdriver 2 Protective cover in the open position Alternately wire connections may be made 3 Tongue terminals being inserted under loosened screws Tighten all connec Ensure that all wires are neatly terminated tions before closing cover with no loose strands Do not strip the insulation back excessively Loose strands and exposed wire beyond the terminals may cause a short circuit and cause protective muting of the amplifier 4 Protective cover shown closed over exiting cables Once all connections have been made close the protective cover by swinging it over the connections and pressing it
26. SA QSC and the QSC logo are registered with the U S Patent and Trademark Office 2000 QSC Audio Products Inc
27. The use of a subsonic filter at the vented box tuning frequency protects speakers from damage and prevents the waste of amplifier power on excessive and inaudible low frequency noise The LF 3 Low Frequency Filter is a new module for tri amp applications The LF 3 provides low frequency bandpass filters for each amp channel and is used in conjunction with XC 3 s to power a tri amp system The XC 3 provides mid and high pass functions for each speaker system The DCM Crossover amp Monitors will work with the ISA amplifiers The AMP TYPE selection in software MUST be set to UN KNOWN This will disable the load fault detection and AC power control as these features are not supported by the ISA series Consult your OSC applications engineer regarding integration of ISA amplifiers with DCM products The CM16a Amplifier Network Monitor will not work with the ISA series of amplifiers Computer data cables although similar in appearance will not I Always use a QSC DataPort cable for remote equipment interconnect function properly and may damage your equipment 32 TROUBLESHOOTING NO SOUND Problem NO SOUND e INDICATION POWER LED INDICATOR NOT ILLUMINATED e Check both ends of the AC line cord for proper connection Both ends should be fully seated in their connectors e Check that the AC outlet works by plugging in a known good device or by testing with a voltmeter If too many amplifiers are used on one outlet the building s circuit bre
28. aker may trip and shut off power If this is the case unplug some of the amplifiers from the outlet reset the building s breaker and try again For the other amps use an outlet that is connected to another circuit breaker to distribute the load current Check the rear panel circuit breaker on the amplifier It should not have its white colored trip indicator showing If it does reset the breaker by pushing the indicator back in until it clicks and locks inward An amplifier which keeps tripping its circuit breaker may have a serious internal fault Turn it off remove AC power and have the amplifier serviced by a qualified technician INDICATION SIGNAL LED S NOT RESPONDING TO INPUT SIGNAL LEVEL NOT LIGHTING e f the green power indicator LED is lit but the signal LEDs do not light up at all check the input Make sure the signal source is working and try another input cable Connect the source to another channel or amplifier to check that it is working e f you are using the XLR or terminal block inputs be sure the connectors are fully inserted at both ends of all interconnecting cables If you are using the DataPort for your input signal ensure the DataPort cable is properly connected at both ends and that the device supplying the audio signal to the DataPort is properly configured INDICATION SIGNAL LEDS RESPONDING TO SIGNAL LEVEL e f the green signal LED indicators are lighting normally the fault is somewhere between t
29. ctable roll off frequencies of 30 and 70 hertz Each channel has its own low frequency filter which can be enabled or defeated using the filter on off switch The frequency is determined by the frequency selection DIP switch There is a 5 hertz roll off in the filter off position to protect the speaker loads from sub audio or DC signals The off position should be used only for subwoofer systems with rated frequency response below 30 hertz or if low frequency filtering is provided by other devices SETTING THE FILTER DIP SWITCHES ISA 300T ISA 500T and ISA 800T s have selectable roll off frequencies of 50 and 75 hertz The frequency is determined by the frequency selection DIP switch The low frequency filter is always active and is not defeatable This is required by the presence of magnetic devices coupling transformers in constant voltage distributed audio systems The low impedance outputs of these models have the same low frequency roll off as the autotransformer coupled high impedance outputs ISA 280 ISA 450 and ISA 750 If operating in STEREO or PARALLEL MODE 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 operating in BRIDGE MODE 1 When in bridge mode channel 2 s low frequency filter and clip limiter should be switched off MODE SWITC
30. d for power input signal and to warn of clipping oD POWER SWITCH power switch is rocker type switch To turn the amplifier on push in on the top portion of the switch To turn the amplifier off push in on the bottom portion of the switch The green power LED should light up when the switch is in the on position POWER When the power is switched off the LED may takes several seconds to go out this is normal If the POWER LED fails to illuminate when the switch is in the ON position 1 Check the AC cord and insure that both ends are fully inserted into their receptacles If the power LED still fails to illuminate 2 Check the AC outlet for voltage with a circuit tester or known good device lamp 3 Check the AC circuit breaker on the rear panel of the amplifier The illustration at the right shows the circuit breaker in its normal operating position and its tripped position amplifier AC power turned off by protective circuit breaker NOTE It is normal for the circuit breaker to open if the Rear panel circuit breaker amplifier is operated continuously at output levels at or Normal operating position exceeding specified power levels If the circuit breaker opens repeatedly with nothing connected to the amplifier and it is connected to the Rear panel circuit breaker proper AC source as labeled on the rear panel serial Tripped or open position number label then the amplifier re
31. dio to other devices Daisy chaining may not be possible with accessories that cover the XLR and or terminal block connectors OSC DataPort Cable carries audio inputs Where It Is The DataPort V2 connector is on the rear panel left side and center D INPUT IMPEDANCE 20K BALANCED A LUOdVLVd 5 25 NA 0 CHANNEL2 Using the DataPort V2 Some DataPort accessories plug directly in to the DataPort while others use an interconnect ing OSC Dataport cable Consult the accessory s documentation for recommended mounting and interconnect information Do not use the XLR or terminal block connections for inputs when the DataPort V2 is used as the input signal source If you do the signals from the DataPort V2 and regular inputs will be mixed possibly with unexpected results Signal to next device s input 10 dB from DataPort V2 10 CHANNEL 1 D dB ATTEN INPUT IMPEDANCE 20K BALANCED UNBALANCED YE 2 dB ATTEN 0 CHANNEL2 Signal to next device s input 10 dB from DataPort V2 Daisy chaining the DataPort V2 input to other devices using the terminal block connectors 9 FEATURES amp SETUP STEREO amp PARALLEL OPERATING MODES STEREO Each input signal is sent to its respective channel Each channel has independent low frequency subaudio filtering clip limiting gai
32. e simply add up all the speaker load powers Below the selected speaker load power is 10 watts If there were 10 of theses exact same loads on the line then the line would represent a 100 watt load to the amplifier s 70 volt output terminals The example would be the same if the system were 25 volt or 100 volt Only the matching transformer would be marked with the 25V or 100V rating and the connections to the amplifier would be at the appropri ate 25V or 100V output terminals 70 Volt Matching Transformer 25watttap 7 m OUTPUTS TO DISTRIBUTED LINES A Swatttap 26 ES 16 ohm tap J Thur mi Y 10 watt tap 8 ohm tap IL p 20 watt tap a N N kohmtap 8 ohm AC loudspeaker ON NS J Lt a Common P I APPLICATIONS LOW FREQUENCY FILTERING amp DISTRIBUTED OUTPUTS Low Frequency Filtering for 70 100V Systems The low frequency filtering is another difference in the characteristics of the non T and the T amplifiers Because transformers and other magnetic devices are prone to low frequency misbehavior called saturation the autotransformer equipped T models are low frequency limited The default low frequency roll off is at 50 hertz 75 hertz is the other available selection Low frequency filtering is always active on the T models This low freque
33. e muting system guards against excessive internal temperatures With normal ventilation and 4 to 8 ohm loads the amplifier will handle any signal level including overdrive Lower load impedances and higher signal levels produce more internal heating When using 2 ohm loads frequent or prolonged clipping may trigger thermal shutdown ON The power switch is a rocker type switch To turn the amplifier on push in on the top portion of the switch To turn the amplifier off push in on the bottom portion of the switch The green power LED should illuminate when the switch is in the on position The LED may takes several seconds to extinguish when the power is switched off this is normal FRONT PANEL LED INDICATORS At full brightness the green power LED indicates that the amplifier is operating Half brightness indicates the amp is in its muting mode As the input signal strength increases the green signal LED indicators will illuminate The red clip LED indicator flashes during overload clipping A bright steady glow indicates protective muting if this occurs during use see Troubleshooting NOTE Page 7 contains detailed descriptions of the LED s and how to interpret their indications A NOTE ON SOUND PRESSURE LEVELS Sound is heard as the ear converts vibration from sound waves into impulses in the nerves of the ear Sounds above 90 decibels particularly if the sound is prolonged may cause such intense vibration tha
34. efaced HOW TO CONTACT OSC AUDIO PRODUCTS m Mailing address Adresse postale Postanschrift Direcci n postal QSC Audio Products Inc 1675 MacArthur Boulevard Costa Mesa CA 92626 1468 USA Telephone Numbers Num ros de t l phone Telefonnummern N meros de tel fono N Main Number Num ro principal Hauptnummer N mero principal 4 714 754 6175 A Sales Direct Line Ligne directe ventes Verkauf Direkt L nea directo ventas 714 957 7100 Sales amp Marketing Ventes amp marketing Verkauf u Marketing Ventas y marketing 800 854 4079 toll free in U S A only sans frais aux U seulement zollfrei nur beim USA sin costo en EE UU solamente Customer Service Service la client le Kundendienst Servicio a la clientela 4 714 957 7150 800 772 2834 toll free in U S A only sans frais aux E U seulement zollfrei nur beim USA sin costo en EE UU solamente Facsimile Numbers Num ros de t l copieur Telefaxnummern N mero de FAX Sales amp Marketing FAX T l copie ventes amp marketing Telefax der Verkauf u Marketing FAX ventas y marketing 714 754 6174 Customer Service FAX T l copie service a la client le Kundendienst Telefax FAX servicio a la clientela 714 754 6173 World Wide Web www qscaudio com E mail info qscaudio com service qscaudio com 39 OSC Audio Products Inc 1675 MacArthur Boulevard Costa Mesa California 92626 U
35. eful guideline may be suitable for low power or low duty cycle applications ISA 300T ISA 500T ISA 800T Tn IHIN E E DIRECT LOW IMPEDANCE OUTPUTS OUTPUTS TO DISTRIBUTED LINES 2 3l WARNING RISK OF HAZARDOUS ENERGY SEE OPERATION MANUAL CLASS 2 WIRING MAY BE USED FOR BRIDGE MONO AND 100V CU DISTRIBUTED OUTPUTS CLASS 1 WIRING MUST 70V QSC AUDIO PRODUCTS INC COSTA MESA CA USA Load sharing between DIRECT LOW IMPEDANCE OUTPUTS and DISTRIBUTED HIGH IMPEDANCE OUTPUTS 1 If 20 or less of the rated per channel power goes to the Distributed loads Hi Z then all specified loads are usable on the Direct outputs Low Z 2 ohm loads require caution 2 If 20 50 of the rated per channel power goes to the Distributed loads then 16 and 8 ohm loads are usable on the Direct ouptputs 4 ohm loads require caution and 2 ohms loads are NOT usable 3 If 50 80 of the rated per channel power goes to the distributed loads then 16 ohm loads are usable on the Direct outputs 8 ohm loads require caution and 4 or 2 ohm loads are not usable 4 If more than 80 of the rated per channel power goes to the Distributed loads then NO LOADS should be connected to the Direct outputs 24 CONNECTIONS SECURING OUTPUT WIRING TO CHASSIS Part of an
36. els 3 43 dBu 1 15 Vrms 2 81 dBu 1 07 Vrms 22 dBu 10k ohms unbalanced 20k ohms balanced 2 81 dBu 1 07 Vrms 35 AMPLIFIER PROTECTION Full short circuit open circuit thermal ultrasonic and RF protection Stable into reactive or mismatched loads COOLING Continuously variable speed fan back to front air flow INDICATORS Front Panel POWER LED green 2 each SIGNAL green and CLIP red LEDs CONNECTORS Input 2 XLR 2 terminal block euro or Phoenix and 1 0SC DataPort V2 connector Output screw terminal barrier strip direct low impedance outputs LOAD PROTECTION Turn on turn off muting Turn on turn off muting Turn on turn off muting AC coupling AC coupling Clip limiting Clip limiting Clip limiting Triac Crowbar OUTPUT CIRCUIT TYPE AB AB Class H POWER REQUIREMENTS SEE SERIAL NUMBER LABEL ON REAR PANEL FOR THE SPECIFIED OPERATING VOLTAGE POWER CONSUMPTION 120 VAC typical both channels driven Idle 1 8 power 8 ohms 1 8 power 4 ohms 1 8 power 2 ohms 0 3 0 4 0 5 2 6 3 5 45 41 5 9 7 0 6 2 9 1 10 3 NOTE 1 8 power is representative of current draw with typical music program material with occasional clipping Pink noise CONTROLS all models DIMENSIONS all models WEIGHT 36 Front AC POWER switch Back Gain controls DIP switch block with 10 poles Clip Limiters Stereo Parallel Bridge mode selection low frequency filter on off and frequency selection 19 00 48 3 cm wide 5 20
37. emperature DO NOT TURN THE AMP OFF This would stop the fan from cooling the inside of the amplifier Instead reduce the input signal or amp gain setting and wait for the amp to resume operation automatically Check for proper ventilation If the fan isn t running at all the amplifier requires servicing 33 TROUBLESHOOTING DISTORTION NO CHANNEL SEPARATION HUM HISS FEEDBACK PROBLEM DISTORTED SOUND INDICATION CLIP LED FLASHING e f the red clip indicator flashes before the signal indicator does the load impedance is abnormally low or shorted Unplug each speaker one by one at the amplifier the clip LED goes out when you disconnect a cable then that cable or speaker is shorted Try another cable and speaker to locate and or remove the fault e INDICATION CLIP INDICATOR NOT FLASHING This could be caused by a faulty speaker or loose connection Check the wiring and try another speaker The signal source may be clipping Keep the amplifier gain controls at least halfway 10 dB or so up so that the source does not have to be overdriven PROBLEM NO CHANNEL SEPARATION e Check the mode switch settings on the back of the amplifier If the mode switches are set for BRIDGE or PARALLEL mode there will be no channel separation The mode switches must be set for STEREO for each channel to operate independently Make sure other equipment in the signal path to the amplifier such as mixers preamps etc is set for stereo not
38. et the DIP switches for bridge mode see below different than other modes See section on Connections Outputs for proper bridge mode output connections 2 Connect the one input signal to CH1 s input XLR or terminal block 3 Connect the one speaker load to the bridge output terminals 4 Use channel 1 s gain control clip limiter and filter SETTING THE DIP SWITCHES FOR BRIDGE MODE ISA 280 ISA 450 and ISA 750 1 Switch 4 5 6 and 7 must all be switched to the 3 Switch 10 should be switched to the left so that channel 2 s clip limiter is off Channel 1 s clip limiter controls both channels in bridge mode USE THE BRIDGE MONO SPEAKER CONNECTION IB MODE SWITCHES RISE right 1 MODE USE CH1 INPUT 2 CLIP LIM AND FILTERS 3 USE CH1 GAIN CONTROL 2 Switch 8 must be switched to the right to disable WAMSTIML CH2 channel 25s low frequency filter 9 5 sWIDHOFFTHECH2 BRIDGE 6 BRIDGE 18 4 MONO OFF 7 MONO ON S CLIP LIM AND FILTER 25 A FILTER ON 8 FILTER OFF mE g SETCH2GAIN OFF oo P rm 9 10 CLIP LIMITER 0N MODE SWITCHES ISA 280 ISA 450 and ISA 750 models switches 4 5 6 7 and 8 must all be set to the right side position Switch 10 should be set to its left side 4 Set switch 1 2 and 3 as required Channel 1 s position See chart above settings determine the bridge mode clip limiting and low frequency filtering ISA 300T ISA 500T and ISA
39. frequency drivers can tolerate all but severe 5 clipping severe clipping can damage any of the systems power components and should be avoided entirely 10 CLIP LIMITER ON OFF 9 ON The clip limiter detects clipping even short events and quickly MODE SWITCHES reduces the gain to minimize the amount of overdrive To CLIP LIMITER selection switches all models preserve as much of the program dynamics as possible the ISA amplifier has limiters which respond only to amplifier clipping Note In BRIDGE mode channel 2 CLIP LIMITER must There is a switchable clip limiter provided for each channel be placed in the OFF position for proper operation When to use it How to use it We recommend using the clip limiters in all applications When driving full range speakers clip limiting reduces high frequency distortion caused by bass overload It also protects high frequency drivers from excess overdrive and harsh clipping harmonics When using 70V or 100V transformers clip limiting prevents excessive overdrive which could saturate the coupling transformers See Low Frequency Filtering For 70 100V Systems page 28 If operating in stereo or parallel mode the two limiters are completely independent of one another 1 Set each channel s clip limiter selection switch on or off as desired Switch 1 sets channel 15s limiter Switch 10 sets channel 2 s limiter If operating in bridge mode channel 1 s clip limiter switch is used
40. he amp and the speakers Check the speaker wiring for breaks Check for proper connection at each end Try another speaker and cable if necessary If your system has multiple speakers connected in series any one speaker failure will cause all other speakers in the same series circuit to loose their signal INDICATION CLIP LED FLASHING e f 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 loose strands of wire and insulate any exposed wire with electrical tape All connections should be made with great care and all wire terminations should be carefully checked to ensure quality workmanship e f the red clip indicator flashes when connecting the speaker cable between the and terminals then that speaker cable or speaker may be shorted Check the cable and the speaker e INDICATION CLIP LEDS BRIGHT AND STEADY The amplifier is in protective muting e Three seconds or so of muting is normal when the amp is turned on After power up muting the clip LED should go out Overheating will cause protective muting and the clip LED to fully illuminate If the amp is overheated the fan will be running at full speed and the chassis will be very warm to the touch sound should resume within a minute as the amplifier cools to a safe operating t
41. he positive terminal is connected to channel 1 s 70 volt terminal and the negative terminal is connected to channel 2 s 70 volt terminal 140 volt Ensure proper polarity is maintained at all connections Note polarity of connection between the two drivers in LE 140 Volt Bridge Connection 200 volt line OUTPUTS TO DISTRIBUTED LINES Connect the 200 volt line between the CH1 terminal and the CH2 terminal WY E23 l nS uw Note that the positive terminal is connected to WARNING ide channel 1 s 100 volt terminal and the negative terminal N CL rid bridde is connected to channel 2 s 100 volt terminal BE USED FOR BRIDGE Ur in Ensure proper polarity is maintained at all connections uns A CH2 Note polarity of connection between the two drivers in series 200 Volt Bridge Connection Do not touch output terminals while amplifier power is on Make all connections with amplifier turned off Risk of hazardous energy OUTPUT TERMINAL SAFETY WARNING A Class 2 wiring may be used For bridged mono and 100V distributed outputs class 1 wiring must be used 23 CONNECTIONS POWER SHARING BETWEEN HIGH amp LOW IMPEDANCE OUTPUTS The ISA 300T ISA 500T and ISA 800T models are equipped with autotransformer coupled high impedance High Z Rated Hi Z If Hi Z Then the following direct out loads are
42. ies connection of 16 ohm speakers is not recommended as the total impedance exceeds specified limits 4series loads Zeq Z1 Z2 23 Z4 Zeq 2 2 2 2 8 ohms Zeq 4 4 4 44 16 ohms Do not use with ISA amplifiers APPLICATIONS MULTIPLE LOW IMPEDANCE LOADS IN PARALLEL all models Multiple Lo Z Loads in Parallel If each speaker load is connected across the same signal source the output of the amplifier then the loads are in parallel with one another If one of the speakers fails in a parallel connected system branch the remaining speakers will continue to operate If all speaker loads are the same impedance the total imped ance of a parallel connected system branch is the impedance of one speaker load divided by the number of loads in the branch example three 8 ohm loads in parallel 8 3 2 667 or roughly 2 7 ohms It is not recommended to connect speakers of different imped ances in parallel because power will be divided unequally between them If you are experienced with mixing and matching speaker loads of varying impedances no damage to the amplifier will result as long as the total impedance is within 2 to 16 ohms per channel PARALLEL LO Z LOADS Zeq is the abbreviation for equivalent impedance and means the impedance at the two connection points Most PA type speaker cabinets are provided with two or more input jacks that are wired in parallel If one cabinet is connected to the ampl
43. ifier the load impedance is equal to the one cabinet s specified impedance If you attach another similar cabinet to the remaining jack of the first cabinet the two cabinets are now parallel with each other and the impedance will be half of the one cabinet value Consult your speaker s documentation for connection details as there are many connection methods in use Below are examples of parallel connections of 4 8 and 16 ohm speakers 2 ohm parallel loads are not usable because the parallel impedance of 2 ohm loads will always be 1 ohm or less this is too low an impedance for most any amplifier Zeq 2parallel loads all same impedance Formula Zeq Impedance of speakers Note Impedance has a phase angle also This is typically neglected in basic speaker calculations Zeq o 3parallel loads all same impedance atz z z c Zeq 4 4 parallel loads all same impedance 1 Zeg s Z1 22 23 24 DO NOT PARALLEL 2 OHM LOADS FOR USE WITH 18 AMPLIFIERS DO NOT PARALLEL MORE THAN TWO 4 OHM LOADS FOR USE WITH ISA AMPLIFIERS 31 APPLICATIONS DataPort V2 all models Below are listed the available OSC DataPort compatible products that will interface with your ISA amplifier This list will continuously change as new products become available and old products are discontinued Always use a OSC DataPort
44. k Gain controls DIP switch block with 10 poles Clip Limiters Stereo Parallel Bridge mode selection low frequency filter frequency selection 19 0 48 3 cm wide 5 2 13 2 cm tall 3 rack spaces 15 75 40 0 cm deep from front mounting rails including rear support ears 44 pounds 20 0 kg 44 pounds 20 0 kg 55 pounds 25 0 SPECIFICATIONS SUBJECT TO CHANGE WITHOUT NOTICE WARRANTY INFORMATION amp HOW TO CONTACT OSC WARRANTY USA only other countries see THREE YEAR your dealer or distributor WARRANTY 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 workmanship for a period of three years from the 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 via prepaid transportation with a copy of the proof of purchase i e sales receipt This warranty provides that examination of the returned 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 d
45. k gain settings input cables connections and audio source If audio source is extremely low signal strength signal LED may not illuminate this is normal but indicates that the input signal strength should be increased Occasional illumination normal for weak input signal strength Illuminated dimly all the time with brighter flashing normal for average input signal strength Fully illuminated on normal for pushing the amplifier hard Also the clip indicator will probably flash dimly with the beat of the program material and brightly during extreme peaks in the material CLIP red LED that illuminates when the amplifier clips Q CLIP O 5 1 CHANNEL 2 MEE Normal indication illumination briefly at extreme output power peaks Occasional clipping once briefly every few seconds when operation at high power levels is normal At power on the clip LEDs may briefly flash this is normal Continuous operation at high power may trigger the thermal protection circuitry shutting down the amplifier and fully illuminating the clip LED Operation will resume after the amplifier has cooled down sufficiently If no indication normal if the amplifier is operated at very low output levels Occasional illumination Occasional clipping once briefly every few seconds when operation at high power levels is normal Continuous operation at high power may trigger the thermal protection circuitry shut
46. l STEREO Ts aJ xh These keys are printed on the amplifiers rear panel for easy 5 mi reference when you are behind the equipment rack BRIDGE BRIDGE EE 1 i MONO OFF LI g ON el 9 15 8 10 LI 110 STEREO Set switch 3 4 5 6 7 and 8 to MODE SWITCHES the left ISA 300T ISA 500T and ISA 800T mode switches PARALLEL Mode Set switch 3 4 and 5 to the right Set switch 6 7 and 8 to the left 11 FEATURES amp SETUP BRIDGE OPERATING MODE amp DIP SWITCH SETTINGS Bridge mode combines both output channels into one output This mode is for driving a single high power rated load with twice the normal voltage swing This results in about 4 times CH 1 input the peak power and about three times the sustained power of a single channel It is also common to call this bridge mono mode When to use BRIDGE mode Use BRIDGE mode when you need to deliver the power of two channels to a single 8 or 4 ohm cde load such as a subwoofer Do not use less than 4 ohm loads in bridge mode Refer to the CONNECTIONS section of this manual for details Constant voltage drivers rated at 140 volts or 200 volts can be accommodated by bridging the high impedance output terminals of the ISA 300T ISA 500T or ISA 8007 Refer to the CONNEC TIONS section of this manual for details BRIDGE MODE OPERATION How to use BRIDGE mode Note that speaker connection for bridge mono mode is 1 S
47. l number located on the rear panel Please write this and the model number down and keep them for your records Model 15 Serial Number Date of Purchase Purchased From FCC INTERFERENCE STATEMENT NOTE This equipment has been tested and found to comply with the limits for a class B digital device pursuant to part 15 of the FCC rules These limits are designed to provide reasonable protection against harmful interference in a residential installation This equipment generates uses and can radiate radio frequency energy and if not installed and used in accordance to the instructions may cause harmful interference to radio communications However there is no guarantee that interference will not occur in a particular installation If this equipment does cause harmful interference to radio or television reception which can be determined by switching the equipment off and on the user is encouraged to try to correct the interference by one or more of the following measures Reorient or relocate the receiving antenna Increase the separation between the equipment and the receiver Connect the equipment into an outlet on a circuit different from that to which the receiver is connected Consult the dealer or an experienced radio or TV technician for help Copyright 2000 QSC Audio Products Inc OSC is a registered trademark of QSC Audio Products Inc QSC and the QSC logo are registered with
48. line of notch notch is 0 40 high x 0 50 deep 19 00 inch ISA Rack Mounting Method 1 he amplifier is first installed from the front of the rack and then the ears are secured directly to the amplifier with two machine screws as shown left hen the ears are secured to the rails using ordinary rail hardware Supporting the Rear of the Amplifier Supporting the amplifier at the rear is extremely important especially for mobile and portable use Equipment is often installed in racks at a remote location then later transported to the installation site During transport the shock loads encoun tered on the chassis and rack can easily damage an unsupported amplifier and the rack rails Unless the amplifier is being installed in its final fixed location we strongly recommend supporting the rear of the amplifier Rear rack mounting ear kits are an accessory item and are available from QSC s Technical Services Department or from your dealer or distributor Method 2 The amplifier is first installed from the front of the rack Then the accessory rear ears are positioned on the rear The rear rack mounting ear kit may be installed in rack rails and secured The pin two different ways Refer to the literature installation position can now be included with the rack mounting ear kit for up to selected Install the pin so that it date information The basic information is ww fits well into the slot provided on supplied here
49. n control and output connection CH 1 input MODE switches When to use STEREO input configuration Use stereo mode 6 for stereo sources L R inputs any other situation that requires each channel to be completely separate from the other CH 2 input How to use STEREO mode 1 Set the DIP switches for stereo mode operation see facing page STEREO MODE OPERATION 2 Connect the two input signals one to CH1 and one to CH2 NOTE Ensure that the MODE SWITCHES are set XLR or terminal blocks to STEREO when feeding two separate signals to the two channels 3 Connect the two speakers one to CH1 s output terminals one to CH2 s output terminals 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 Each channel s low frequency filtering clip limiting and gain control still function independently Each channel drives its own speaker CH 1 input load 1 I is an 7 MODE switches You can patch the input signal on to additional amplifiers daisy set for PARALLEL chain by using any of the remaining input jacks This feature eliminates the need for Y cables CH 2 input When to use PARALLEL input configuration Use parallel not used mode when you need one signal to drive both channels each U channel having its own control gain
50. ncy roll off is required primarily to protect the smaller matching transformers on the speakers of constant voltage distributed audio systems but also aids in minimizing low frequency distortion of the system in general The varying degree of quality of coupling transformers may require the roll off frequency to be set to the higher 75 hertz selection The change from 50 to 75 hertz may seem minor but in terms of low frequency drive it reduces the required magnetic flux of the coupling transformers by about 30 If the application requires driving speaker loads at or near their rated power or with program material that s heavy on the bass a marked performance increase may be realized with the 75 hertz low frequency roll off A careful system listening evaluation will aid in the best selection for any application The low frequency filter is not a brick wall and if the input level is increased beyond 100 it is possible to over ride the filter to some extent Normally such signal levels will cause the amplifier to clip which is the first sign of potential danger Midband clipping puts no unusual strain on the transformers but full range material with heavy clipping will probably overdrive the 70 100V transform ers to satuartion even with the 50 Hz filter This will cause an additional layer of hash in the clipping and will also result in audible clicking noises from the transformers inside the amplifier These symptoms indicate abnormal s
51. ned off Risk of hazardous energy outputs class 1 wiring must be used 22 CONNECTIONS OUTPUTS DISTRIBUTED HIGH IMPEDANCE HI Z BRIDGE MODE BRIDGE mode operation combines the output power of both channels into one channel that has twice the normal voltage swing This means that in BRIDGE mode the high impedance distributed outputs can provide 140 volt 70 volt 70 volt and 200 volt 100 volt 100 volt drive There are not many drivers speaker loads that operate at 140 or 200 volts but if required the ISA T models can easily be configured to fit the application 140 and 200 volt bridging may be useful for installations where two 70 volt or two 100 volt drivers are connected in series An example of each of these situations is provided below Consult local and national electrical codes to ensure that proper wiring materials and methods are used NOTE When the MODE SWITCHES are set to BRIDGE mode all output connections are configured for bridge mono operation All output connections low impedance direct AND high impedance distributed must be made bridged BRIDGE CONNECTION TO DISTRIBUTED OUTPUTS OUTPUTS TO DISTRIBUTED LINES 140 volt line Connect the 140 volt line between the CH1 terminal and the CH2 terminal CH1 WARNING RISK OF HAZARDOUS ENERGY SEE OPERATION MANUAL CLASS 2 WIRING MAY BE USED FOR BRIDGE MONO AND 100V DISTRIBUTED OUTPUTS CLASS 1 WIRING MUST BE USED Note that t
52. odes must be used to connect the speaker To prevent electric shock do not operate the amplifier with any conductors of the speaker cable exposed Consult the local amp national electrical codes for full information 21 CONNECTIONS OUTPUTS DISTRIBUTED HIGH IMPEDANCE HI Z STEREO amp PARALLEL The ISA 300T ISA 500T and ISA 800T amplifiers have high impedance Hi Z outputs suitable for driving 25 70 and 100 volt distributed audio lines These loads should be driven by the amplifier in stereo or parallel modes For 140 volt or 200 volt output the amplifier must be configured for bridge mode Bridge mode connections to the high impedance distributed outputs is discussed on the following page In the diagrams below only one speaker load for each channel is shown for clarity Distributed lines usually have several speaker loads on each output line Stereo and Parallel Amplifier Mode Distributed Output Connections Use these terminals for 25 70 or 100 volt distributed loads when the amplifier is in stereo or parallel mode 25 volt lines Connect one of the 25 volt lines to the CH1 terminals marked 25V OUTPUTS TO DISTRIBUTED LINES Connect the other 25 volt line to the CH2 terminals marked 25V WARNING RISK OF HAZARDOUS ENERGY SEE OPERATION MANUAL CLASS 2 WIRING MAY BE USED FOR BRIDGED AND 100V The 25V connection is between the LASS 1 WIRING MUST markings
53. quires servicing press to reset COOLING AIR INLET AND EXHAUST VENTS lt Keep the inlet and exhaust air vents clear of any obstructions Insure pie lt lt that the air exhausted from the vents has an exit from the equipment A lt coo enclosure uot 4 m CE P lt Equipment enclosures with insufficient air flow will cause amplifier overheating Enclosures must allow fresh air to enter and hot air to exit RACK If dust builds up clogging the vents use a soft brush and a vacuum cleaner to remove the dust Use the brush to loosen the dust while the vacuum is used to pull the dust away from the amplifier FEATURES amp SETUP LED INDICATORS P s POWER green LED that illuminates when the power switch is set to the on position and AC power is present at the IEC cord receptacle POWER Normal indication at power on the LED will illumi nate at half brightness for 2 3 seconds then it illumi nates to full brightness If no indication see previous page for suggested items to check When power is switched off the LED may take several seconds to extinguish go out this is normal Q 0 SIGNAL green LED that lights up when the input siena O signal is strong enough to drive the output to about 40 1 cu 2 from rated 8 ohm power Normal indication varying brightness corresponding to strength of input signal If no indication chec
54. r label constitute the risk of electric shock Verify the correct AC line voltage by checking the f Connecting to the wrong line voltage is dangerous and may damage the amplifier or specification printed on the serial number sticker on the rear panel 17 CONNECTIONS INPUTS XLR amp TERMINAL BLOCK Each channel has active balanced Euro style terminal block and XLR input jacks wired in parallel The input impedance is 20k ohm balanced or 10 k ohm unbalanced Unused input jacks may be daisy chained to additional amplifiers Balanced connection is recommended Balanced signals are less prone to AC hum and other electrical noise Unbalanced signals can be suitable for short cable runs The signal source s output impedance should be less than 600 Ohms to avoid high fre quency loss in long cables If the DataPort V2 is being used for the input signal source the XLR and terminal block connections should not be used for inputs However they may be used for daisy chaining the DataPort V2 input signal to other amplifiers The signal available from the XLR and terminal block connections will be about 10 dB lower than the DataPort V2 signal Terminal Block Connectors shown Terminal block balanced connections 25 Balanced inputs Connect the j id conductors to the connector as XLR CONNECTORS X De TERMINAL BLOCK CONNECTORS CHANNEL 1 dB ATTEN 25 INPUT IMPEDANCE 20K BALANCED 10K UNBALAN
55. ration to the right shows a typical two zone 100 volt system When using 100 volt speaker loads make sure that connec tions to the amplifier are made to the 100 volt output terminals If using the ISA 300T 300 watts per channel OUTPUTS TO DISTRIBUTED LINES zone can be delivered Make sure that the T total speaker power load on each channel O T does not exceed 300 watts A E Ww WARNING mi PIS ENERGY SEE rd If using the ISA 500T or ISA 8007 the per reperi E channel power limit is 550 and 800 watts VL EAR 1 i respectively Ol CH2 OSE AUDIO PRODUCTS INC COSTA MESA USA Bridge Mode Using Hi Z Outputs Bridging of the Hi Z outputs is possible with the T models see page number 22 OUTPUT TERMINAL SAFETY WARNING with amplifier turned off Risk of hazardous energy 3l 3 3l ww Jl E Do not touch output terminals while amplifier power is on Make all connections Class 2 wiring may be used For bridged mono and 100V distributed outputs class 1 wiring must be used 29 APPLICATIONS MULTIPLE LOW IMPEDANCE LOADS IN SERIES all models Multiple Lo Z Loads in Series Series connection is where the same signal current flows through each of the speaker loads The signal goes into one terminal of the first speaker and out its other terminal then the signal goes into one terminal of the next
56. requency filters QSC s rear to front airflow cooling helps to keep other system components in the equipment rack cooler enhancing overall system reliability FRONT PANEL all models For those systems with QSC DataPort accessories DSP crossovers amp filters remote cinema monitoring a DataPort V2 version 2 is included on all ISA models Consult your QSC representative for accessory compatibility information The ISA amplifiers are easy to use All operating mode switches are grouped together on the rear panel A mode switch configuration chart is printed directly on the rear panel for easy accurate reference This helps to avoid configuration problems On the autotransformer coupled T models separate screw terminal output connections are provided for both low impedance loads and high impedance 25 70 100 volt loads The connectability of the T models makes them simple to use in almost any installed sound application The ISA amplifiers are built for long service life XLR and terminal block input connectors provide tight noise free connections The chassis design incorporates robust output cable dressing tie down points to keep stress off the connec tions making them more reliable signal processing is done in side loops and then returned to the main signal path This maintains high signal fidelity and provides a more robust system Your new ISA amplifier will give you many years of great sound It is the best val
57. sssssssessessessessesseessesessesseesesteeseeseeaees 32 TROUBLESHOOTING nente nere et 33 SPECIFICATIONS u 5 notet tenete pedet temet tt antt 35 WARRANTY INFORMATION 39 HOW TO CONTACT OSC AUDIO PRODUCTS 39 INTRODUCTION INTRODUCTION AND FRONT PANEL ILLUSTRATION Thank you for the purchase of your new ISA amplifier To get the most out of your amplifier review this manual carefully The installation connection and operation sections provide useful guidelines to get you up and running quickly and correctly The OSC shipping box should contain 1 The amplifier 2 This user manual 3 14AWG AC line cord with IEC connector After you have removed the amplifier from the box make sure you save the box and packing material for safely storing or shipping the amplifier in the future The ISA Series amplifiers offer professional quality perfor mance at an affordable price Three power points are offered in both directly coupled and autotransformer coupled output Output power at 2 ohms ranges from 430 to 1200 watts per channel The ISA amplifier was designed to fit your installed sound requirements The detented gain controls located on the rear panel provide accurate repeatable adjustments Fach channel has defeatable clip limiting and selectable response low f
58. t OPERATING VOLTAGE AC mains Connect the AC line cord after the amplifier has been installed in the equipment rack The IEC plug the rectangular block plug end of the AC power cord can only be inserted when it is properly oriented with the IEC receptacle on the rear panel of the amplifier Orient the IEC plug correctly and push the plug firmly into the IEC receptacle it should seat tightly The correct AC line voltage is shown on the serial number label Connecting to the wrong line voltage is dangerous and may damage the amplifier The AC line cord attaches to the IEC connector on the rear panel Use the cord supplied with the amplifier or an equivalent Insure that the wire gauge of the cord is 14AWG Use of 16 or 18 AWG can be dangerous and is not recommended The larger AWG number indicates a physically smaller wire smaller AWG number indicates a physically larger wire 12 AWG is able to carry more current than 14AWG Use the best possible connection to the AC power source Avoid extension cords as they will cause some voltage drop between the AC source and you amplifier If the use of an extension cord is required ensure that it is the shortest length possible and is at least 14 AWG Smaller AWG number means larger wire size example 12 AWG is a larger physical wire size than 14 and able to carry more current Ensure that all grounding connections are maintained The correct AC line voltage is shown on the serial numbe
59. t the inner ear is damaged 90 decibels is about the loudness of a large truck about 5 yards away A jackhammer emits sounds of about 120 dB from 3 feet away and a jet engine emits sound of about 130 dB from 100 feet away Motorcycles snowmobiles and similar engines range around 85 to 90 dB and a rock concert may approach 100 dB A general rule of thumb is that if you need to shout to be heard the sound is in the range that can damage hearing Some jobs in the entertainment industry involving loud noise from music carry high risk for hearing loss In the U S the maximum job noise exposure is regulated by law Both the length of exposure and the extent decibel level of exposure are considered If exposure is at or greater than the maximum exposure protective measures must be taken The table at Sound Level dBA slow response Duration of Exposure per day in Hours right is referenced from OSHA s Permissible Noise Exposure table G16 26 APPLICATIONS GENERAL APPLICATION INFORMATION General ISA Application Information The ISA 280 ISA 450 and ISA 750 amplifiers are optimized for directly driving low impedance loads Low impedance Lo Z loads are those loads between 2 and 16 ohms These models are not suitable for driving constant voltage 70V lines These low impedance models are referred to collectively as the non T models The Lo Z outputs will handle impedances down to 2 ohms 2 ohm loads demand substantially higher
60. the U S Patent and Trademark Office The Audio Precision logo is the property of Audio Precision Beaverton OR All trademarks are the property of their respective owners TABLE OF CONTENTS INTRODUCTION IS A Series DVBEVIBWE Roc es 4 Front Panel Illustration eere eei 4 Rear Panels Illustrations a sss a t SH kusha 5 FEATURES amp SETUP POWERS WITCI e Cooling Air Inlet and Exhaust Vents 6 u teret oro eee Ht DS Pme 7 5 assesses tete tote unen but debes a 8 Input A KS ete ses tet todo setenta de reote et tiit 8 DataPort V2 cou etes e m teet a 9 Daisy Chaining to Other Devices from the DataPort 2 9 Stereo amp Parallel Operating Modes 10 DIP SWItEI Vect oret teet eee 11 Bridge Mono Operating Mode ssssssssssseemm 12 DIP Switch Settings irent eret 12 LOW Erequerey EIEGE uice ble i Ett Sette to e etas 13 DIP SWICISS EHI Sa m uuu a e teet ot etes 13 Frequency Response CUIVES tede rete eer tiet jeg 14 toe ER e EDU ete 15 DIP Switeli Settlngs usines ettet ette de ette mde 15 INSTALLATION Hack
61. ting down the amplifier and fully illuminating the clip LED Illuminated most of the time Not normal reduce the output of the amplifier and or input signal to avoid thermal shutdown of the amplifier and possible speaker damage Fully illuminated on Amplifier is in thermal shut down Reduce gain settings or input signal and allow the amp to cool down Leave the power on so that the fan continues to run operation will automatically resume after the amplifier has cooled sufficiently FEATURES amp SETUP GAIN CONTROLS amp INPUT JACKS GAIN CONTROLS WHERE THEY ARE The Gain controls are located on the rear panel to minimize POK BALANCED M control tampering after installation When viewing the amplifier te i Y CHANNEL 1 from the rear they are on the left end top and bottom as shown O EE ATTEN TT in the illustration to the right dU a The Gain controls are detented 11 steps for repeatable adjustment Surrounding the Gain control the power attenua 0 tion level is shown in dB To operate the Gain control rotate the x AE 3 4 CHANNEL 2 control s knob so that the desired level is achieved There is a X 2 dB ATTEN detent in the knob to indicate its position eee Maximum gain depends on the model see chart below QNA ATTEN CHANNEL 2 MAXIMUM VOLTAGE GAIN BY MODEL ISA 280 300T ISA 450 500T
62. to give you an idea of how the accessory rack mounting ears are used 16 the amplifier s rear mounting tab INSTALLATION COOLING REQUIREMENTS amp AC MAINS FAN COOLING All OSC amplifiers draw cool air into the rear of the amplifier and exhaust the hot air from the front This is done so that the equipment in the rack stays as cool as possible This method of WARM cooling also gives the technician direct air temperature EXITS feedback at the front of the rack where it is the most conve iX nient The front panel s temperature is an accurate indicator of MPUFER how hard the amplifier is working AMPLIFIER P COOL AIR ENTERS REAR lt OF AMPLIFIER AMPLIFIER The fan varies speed automatically to maintain safe internal temperatures and minimize noise Keep the front and rear vents clear to allow full air flow Hot air exhausts out the front of the amp so it does not heat the Air flow in OSC amplifiers interior of the rack Make sure that plenty of cool air can enter the rear of the rack especially if there are other units which exhaust hot air into it Also ensure that the exhaust air from the front of the amplifier is not obstructed by an equipment cabinet door or otherwise Keep the front and rear vents clear to allow full air flow Make sure that plenty of cool air can enter the rack especially if there are other units which exhaust hot air into i
63. toward the STACKING OF TONGUE TERMINALS amplifier If you wiring job is messy you may need to loosen and reposition some cables to get a good fit for the cover If you need to fit two tongue terminals onto one screw they should be oriented properly for a good fit and reliable connection Refer to the diagram below Place the flat sides of the two terminals toward one another then tighten screw RECOMMENDED TONGUE TERMINAL SIZE If oriented incorrectly the terminals will bend and possibly not The tongue terminals should connect very well The screw terminal may also be damaged have an overall width of the RETAINING SCREW TONGUE TERMINALS tongue no larger than 0 320 m inch The opening for the fe 2 screw should be no smaller than 0 135 inch The wire insertion barrel should be rone sized for the size of speaker cable used 4 gt 6 is the screw size used on the ISA output terminals this 0 320 maximum is also the size that tongue 8 1 mm terminal suppliers may use in their nomenclature CORRECT STACKING INCORRECT STACKING 20 CONNECTIONS OUTPUTS DIRECT Low IMPEDANCE 10 2 ISA amplifiers are equipped with screw terminal output connections The ISA 280 ISA 450 and ISA 750 provide low impedance outputs only 2 to 16 ohms while the ISA 300T ISA 500T and ISA 800T provide both low impedance and high impedance 25V 70V and 100V outputs
64. tress and should be avoided for maximum service life If unpredictable clipping is possible use the Clip Limiter to prevent long term overloads and use the 75 Hz filter position for extra protection The clip limiter will not effect performance where no clipping is present and therefore is recommended as the default setting The 50 Hz filter is suitable for program material which remains within the amplifiers normal headroom and will provide slightly better bass on wide band speakers If a system with sub woofers is desired we recommend the use of the low impedance ISA 280 ISA 450 or ISA 750 with low imped ance sub woofer drivers The low frequency performance of the directly coupled system is superior to the magnetically coupled systems Remember that all of the outputs on the T models are low frequency limited to 50 hertz by default For all applications requiring audio performance below 50 hertz use the low impedance non T models with low impedance speakers Distributed Output Application Examples 29 VOIE wo Zone example ISA 3007 ISA 5007 ISA 800T ZONE 1 ZONE 2 TS The illustration to the right shows a typical HUNE e 3 two zone 25 volt system When using 25 volt gt II 2 speaker loads make sure that connections to the amplifier are made to the 25 volt output terminals If using the ISA 300T 300 watts per channel El
65. ts 10 Circuit Breaker for AC Power 3 DataPort V2 Connector 7 Cooling Air Inlet Vent 11 Tabs for Securing Output Wires 4 XLR Inputs 8 Output Connections Low Impedance 12 AC Power Connector IEC type NOTE Output connection terminals shown without protective cover in place for clarity rear panel above amp below REAR PANEL ISA 300T ISA 500T ISA 800T 8 9 10 11 12 was PEE 1 IMPEDANCE OUTPUTS cH mons Eu g ZA1u04VvlV0 SC AUDIO PRODUCTS INC COSTA 4 CA USA up ser ng e 7 ane mor 25 67 Se THE BID MONO SPENNER CONNECTON BREAKER 25N _ ATTEN 5 0 CHANNEL 2 1 Gain Controls 5 Mode Switches 9 Serial Number Label 2 Terminal Block Inputs 6 Mode Switch Configuration Charts 10 Output Connections Distributed high impedance 3 DataPort V2 Connector 7 Cooling Air Inlet Vent 11 Circuit Breaker for AC Power 4 XLR Inputs 8 Output Connections Low Impedance 12 Tabs for Securing Output Wires 13 AC Power Connector IEC type FEATURES amp SETUP POWER SWITCH COOLING AIR VENTS The front panel of ISA series amplifiers is tailored for installed 0 N sound The power switch is the only front panel control gain Mz o controls are located on the rear panel to minimize control tampering LED indicators are provide
66. ue in installed sound amplification with legendary OSC durability and performance MODEL ISA750 PROFESSIONAL AMPLIFIER O tr Q siemi O 1 CHANNEL 2 1 Power indicator LED 2 Power switch 3 Clip and Signal indicator LEDs 4 Cooling air exhaust vents 5 Mounting holes for optional handles 6 Mounting holes for rack mounting INTRODUCTION REAR PANEL ILLUSTRATIONS REAR PANEL ISA 280 ISA 450 ISA 750 5 6 li E o x es cb 4 0 CHAN y AA 1 9 mms lt 222 SS Z DIRECT LOW IMPEDANCE OUTPUTS em mes EE d Ke a u a MODE SWITCHES d sme NIA IET wm E 2 F moe f Sener corr Lue 7 nove ou j POF usns Em t ma Em cm y CLIP LIMITER on MODE SWITCHES sone H CONTROL E I LU ros xD d sati oo gt 4 WI EE BREAKER as ATTEN CHANNEL 2 1 Gain Controls 5 Mode Switches 9 Serial Number Label 2 Terminal Block Inputs 6 Mode Switch Configuration Char
67. y quality sound system installation is ensuring that your connections remain tight and reliable over time Making high quality terminations to the screw terminals is one part of that reliability equation Keeping those terminations from moving is the other part If the connections are prevented from stress and strain they should remain reliable AIl ISA amplifiers have integral wiring tie down points stamped into the steel chassis When used properly they will help keep your connections reliable Securing the wires to the tie down tabs will keep the stress of wire movement and inadvertent pulling off the connections These tie down points are located on the rear panel right side above the IEC power connector After all connections have been made and verified carefully dress the wires into neat lines straight form the connection and across the tie down tab Working from one end to the other secure each lead or group of leads to its respective tie down tab Continue until all wires have been secured Tie Wrap plastic wire securing strap Thread tie wrap through chassis tab then capture wire with tie wrap and secure DIRECT LOW IMPEDANCE OUTPUTS OUTPUTS TO DISTRIBUTED LINES WARNING RISK OF HAZARDOUS To Speaker Loads ENERGY SEE OPERATION MANUAL E CLASS 2 WIRING MAY BE USED

ISA 800T - R.S. Engineering and Manufacturing

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