GTS100 2/1 CHANNELAUTOMOTIVE POWERAMPLIFIERowner's MANUAL

Table Of ContentsIntroduction..................................................................................................3

Features......................................................................................................4

About Installation........................................................................................4

Quick Start...................................................................................................5

System Design Using the GTS100................. ...........................................6

Typical Applications.....................................................................................7

Installation Precautions................................................................................9

Physical Installation .....................................................................................9

Controls and Connectors...........................................................................10

Mounting Instructions—.......................................... .................................12Wiring.........................................................................................................12

Power Supply Connections........................................................................14

Audio Input Connections............................................................................15

Speaker Connections................................................................................17

Operation...................................................................................................20

Solving Noise Problems.............................................................................21

Maintenance..............................................................................................24

Additional System Configurations for Add-On or Upgrade ........................24

In Case of Difficulty....................................................................................27

Specifications.............................................................................................29

Owner's Warranty Information Records

Model NumberSerial Number

Dealer Name

City, State, Zip Sales

Receipt Number Date of

Purchase

IntroductionThanks for purchasing your new GTseries automotive amplifier. The GTseries amplifier you have chosenincludes many unique features toenhance its performance and utility. Thepower amplifier circuitry is a fullydiscrete design notable for low distortionand unusually clean and clearreproduction quality. Your GT seriesamplifier will easily connect to virtuallyany car audio system, whether it isfactory installed or purchasedseparately.In addition to conventional preamp-levelinputs, this model features JBL'sUniversal Interface design, which facili-tates simple connection to factory radioswith the low distortion that is usuallyonly associated with preamp levelconnection. With Universal Interface, afactory radio can be used either as themain music source or combined with aCD changer which includes volumecontrol capability, simultaneouslyconnected directly to the amplifier.

By providing this two-unit direct connec-tion, Universal Interface circuitry elimi-nates the need for an FM modulator toconnect a CD player to factory radios,improving the fidelity of digital playback.Also, when using a high-powered (BTL)radio through the speaker-level inputs,Common Sense turn-on circuitrysenses the common-mode voltagepresent on the radio's speaker wiresand turns the amplifier on without anadditional "remote" wire. When thespeaker-level inputs are used exclu-sively, the preamp-level inputs may beconverted to preamp-level outputs todrive additional amplifiers or signalprocessors.In addition, the built-in active crossoverprovides either high-pass or low-passoperation. This lets your GT seriesamplifier power either subwoofer ormain speakers in a bi-amplified system,without the expense of an additionalcrossover.

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Features

• Bridgeable 2/1 Channel Operation

• Simultaneous Stereo + MonoOperation

• Built-in Staggered 18dB/Octave"lOOHz High-Pass and 80Hz Low-Pass Crossover

• No Current Limiting

• Oversized Floating Rail MOSFETSwitch-Mode Power Supply

• Common Sense 2-way Turn-On

• Stealth Remote Silent Turn-OnCircuitry with Power-On Indicator

• Continuously Adjustable Gain Controls

• Capable of Single-Ended OperationInto 2-Ohm Loads.

• Fully Complementary, Direct-Coupled,Discrete Power Amplifier Circuitry

• Gold Plated RCA Input Connectors

• Preamp Output Capability

• Convenient Easy-Disconnect Powerand Speaker Connections

•Third Order (18dB per Octave),Capacitive/lnductive Power-SupplyFiltering

• Input Mode Switching

• Made in USA

About InstallationAlthough the GTS100 was designed tomake installation as easy as possible, itis a sophisticated product that requiresproper installation to realize its full per-formance potential. Skill with tools, anunderstanding of basic electronics, andexperience with car stereo installationare needed to properly install theseamplifiers. If you feel you do not havethe necessary knowledge and skills, westrongly recommend that the instal-lation be done by your authorizedJBL dealer. If the GTS100 is installedby a qualified JBL dealer, we will doublethe length of your warranty to two yearsfrom date of purchase.If you choose to install the GTS100yourself read all of the information in thismanual before you start the installation.Pay particular attention to the safetyprecautions and notes.It will save potential problems later if youtake a few minutes to plan the completeinstallation before you start. The routingof wires, the power supply connectionpoints, and the mechanical installationof the unit should be completely thoughtout before you begin. Work carefully andcheck each step as it is performed.Before operating the amplifier, recheckthe entire installation to be sure thateach connection is correct, properlyinsulated and secure.

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Quick StartRecommended for experiencedprofessional installers only!1. Disconnect the negative cable from

the battery. Note: If the vehicle'sradio features a code type securitysystem, make certain you know thecode before disconnecting thebattery!

2. Mount the amplifier to the desiredlocation using four screws.

3. Run a minimum AWG #10 powercable complete with a 20 amp fuse(not included) directly from the posi-tive +12V battery terminal to thedesired amplifier location. Keep thefuse to within 5" of the batteryterminal, and before the wire runsthrough any metal partition.

Note: All wiring connections should bemade either by soldering with heat-shrinktubing insulation or with high quality crimptype insulated connectors installed with agood crimping tool. Soldering crimpconnections is recommended to furtherenhance connection reliability. Never usewire-nuts, insulation-displacementconnectors (i.e. ScotchLok type), or "twistand tape" connections. Do not use electricaltape;it will loosen with age and extremetemperatures. Never leave bare wireexposed.

4. Connect power wiring as shown inthe Wiring Diagram on page 13,using the supplied power harness.

5. Connect the outputs from the signalsource to the appropriate inputs ofthe amplifier according to the WiringDiagram (page 13) with either highquality low-level signal cables withRCA plugs, with the suppliedSpeaker-level input connector, orboth.

6. Connect the speakers to the amplifieraccording to the wiring diagram onpage 13.

7. Turn the input sensitivity adjustmentto the V4 position.

8. Set the input level switch to "line" ifyou are using the line-level (preamp)inputs.

9. Set the crossover switch as desired.10. Set the input mode switch to stereo,

left + right or right input onlyoperation.

11. Reconnect the negative batterycable.

12. Turn on the signal source at a lowvolume level and check for thecorrect output from each speaker.

13. Adjust the amplifier gain control,using the procedure described in theGain Adjustment section on page20.

14. Read the rest of the manual to getmaximum use and enjoyment fromyour amplifier.

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System Design Using theGTS100

SpeakersWhen used in the non-bridged mode,the GTS100 can easily drive 2 ohmspeaker loads. When only one speakeris connected to each channel, virtuallyany common speaker may be used.When two speakers are connected inparallel to a given channel, eachspeaker must have a minimumimpedance of at least 4 ohms to ensurethat the combined load does not dropbelow 2 ohms. Although the amplifierwill not be damaged, load impedanceslower than 2 ohms will eventually causethe amplifier to overheat, activating theprotection circuits and causing the unitto shut off until it cools down sufficiently.

Parallel Wiring

When the GTS100 is in bridged mode,the combined impedance of the speaker(or speakers) connected to the bridgedchannel should be at least 4 ohms. As inthe example above, sustained operationof the GTS100 in bridged mode withless than 4-ohms will likely causeoverheating. If monaural operation isdesired, and two 4-ohm speakers areused, it is best to connect each speakerto an individual amplifier channel anduse the "L+R" mode on the input-modeswitch to provide monaural operation.The GTS100 must not be used withspeakers that have either one of theirinput terminals wired to the frame ofthe speaker or to the chassis of thevehicle.Signal SourcesThe low level preamp outputs of anyradio/tape deck, CD player or preamp/equalizer so equipped can drive theGTS100. The Gain control of theGTS100 is used to match the amplifierto the output voltage of the source. Thismatching is important to keep noise lowand is explained in the GainAdjustments section of this manual(page 20).Thanks to Universal Interface circuitry,the GTS100 can also be connected topower amplifiers, radios or equalizersthat are equipped with only speakeroutputs by connecting them through thespeaker level input connector. Inside theGTS100, the speaker-level and preamp-level inputs are connected through amixing circuit, which allows them to beused simultaneously. Therefore a lowlevel source, such as a CD playerequipped with preamp

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controls (Volume, Balance, Bass,Treble) may be connected to the pre-amp-level inputs at the same time as apowered radio/tape unit is connected tothe speaker-level inputs. This providesa higher performance alternative to anFM Modulator connection when youwish to add CD capability to a factoryinstalled cassette radio. Switching fromone source to the other is as simple asturning the desired source on and turn-ing the undesired one off — no addi-tional switches or relay connections areneeded.

Other ComponentsThe system options of the GTS100 arenumerous. All JBL amplifiers aredesigned with sufficient adjustmentrange to match with the accepted "nor-mal" voltages and impedances used byvirtually all car audio components. Withvery few exceptions, the GTS100 willmatch correctly to any equipment youalready have.

Typical ApplicationsThe following diagrams show the most common basic system configurations using theGTS100. More elaborate systems are formed by using a combination of these "buildingblocks." For additional ideas, refer to the "Add On and Upgrade Section" near the end ofthis manual.

Application 1Stereo Full-Range or Subwoofer

Operation

Main speakers are driven by head unit or additional amplifier.

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Installation PrecautionsBefore beginning the installation of theamplifier, read the following precautionscarefully. Failure to heed these warningscould result in personal injury ordamage to property.• The GTS 100 should be installed only

in vehicles that have 12-volt negativeground electrical systems.Connection to other types of electricalsystems may damage the amplifierand/or the vehicle's electrical system.

• Before beginning the installation, dis-connect the negative (ground) cablefrom the vehicle's battery. This willprevent accidental short circuits whileworking on the installation. Reconnectthe cable only after the installation iscomplete and the wiring has beencarefully checked to be sure there areno exposed wires or short circuits andeverything is properly and securelyconnected. Note: If the vehicle's radiofeatures a code type security system,make certain you know the codebefore disconnecting the battery!

• Work in an area that is well ventilated.• Wear eye protection whenever cutting,

drilling or filing any parts of thevehicle.

• Wear ear protection when using highspeed drills, saws, sanders, orgrinders. We want you to be able toenjoy the system once it is installed.

• Before cutting or drilling any holes inthe vehicle, inspect the area carefullyto be sure there are no electrical

wires, hydraulic brake lines, fuel lines,or fuel tanks that may be damagedwhile doing so. Such components maybe hidden within double walled panelsor structural members of the vehicle,so be extremely cautious.

• Do not bypass or modify the fuse onthe chassis of the amplifier. Do notreplace the fuse with one rated forhigher current levels. Doing so couldresult in damage to the amplifier andthe vehicle's electrical system.Repeated blowing of the powersupply fuse indicates a fault withinthe amplifier or problems in theinstallation.

• An additional power supply fuse (notincluded) should be located as closeas possible to the battery on the+12V wire to minimize the chance ofelectrical system damage or fire inthe event of a short circuit in thepower supply wire.

Physical InstallationThere are several factors to considerwhen selecting a mounting location fortheGTS-IOO.• It must be solidly mounted in a place

where it will not be subjected toexcessive shock and vibration.

• Under no circumstances should theamplifier be mounted where it will beexposed to moisture or extreme heat.

• Try to mount the amplifier where themain +12 volt power supply wire,which must be connected directly tothe battery, can be kept relativelyshort.

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The GTS100 must be mounted in aplace where air can circulate aroundthe fins on the chassis. Good aircirculation around the amplifier willmake it operate at lower temperaturesand reduce the chance of the thermalprotection circuits being triggered. Theinstallation positions that provide themost efficient air circulation around theamplifier are shown below.Use a mounting location that allowsaccess to the wiring connections andlevel adjustments. This allows the unitto be mounted before these con-nections and adjustments are made. Ifthe amplifier must be mounted in aninaccessible location, it may be easierto mount it after the wiring connectionsand level adjustments are complete.

Controls and Connectors1. Line Level RCA Inputs - Use theseconnectors for line (preamp) level inputto the amplifier. When speaker inputsare used, this connector can be con-verted for use as a line-level output bysetting the "Line" switch to "out."2. Line Selector- This switch sets theline level connectors for either input oroutput. Set switch to "In" for normal linelevel input operation." Set the switch to"Out" to use the line level connector forline level outputs to drive other ampli-fiers or signal processors when usingthe speaker level inputs.3. Gain Control- Use this control toadjust the input sensitivity of the ampli-fier. See the "Gain Adjustments" sectionfor tips on proper setup.4. Input Mode Selector- This switch isused to set the input mode for both pre-amp and speaker-level inputs. Set thisswitch to Stereo for normal operationusing both left and right inputs. Set thisswitch to R to drive both the left andright channels with only a single inputon the right channel. Set this switch to"L+R" to sum the left and right inputs fora mono output on both amplifierchannels.5. Speaker Input Connector - Use thisconnector for speaker level input sig-nals. A wire harness is supplied for thisconnector. See the "Audio InputConnections" section (page 15) forwiring instructions. This input alsoincludes JBL's Common Sense inputcircuitry which turns the amplifier on assoon as a high powered head unit con-nected to this input is turned on.

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6. Crossover Mode Selector- This switchcontrols the built in crossover. Set the switchto "Off" for full band operation. Set this switchto "Low" to activate the 80HZ low pass filteron the amplifier (for subwoofer use). Set theswitch to "High" to activate the "lOOHz highpass filter for use with satellite speakers.Note that the filter does not affect the linelevel outputs on the amplifier.

7. Fuse - 20 Amp ATC type Fuse.8.. 9., 10. Power Connector-Connection forincluded power wire harness. See "PowerSupply Connections"

on page 14 and the wiring diagram on page13 for information on wire color codes andproper connections.11. Speaker Output Connector-Connectionfor included speaker output harness. See"Speaker Connections" section on page 17for information on wire color codes.12. Power Indicator LED - Power indicatorlight glows for normal operation when theamplifier is activated by either the remote orcommon sense turn-on circuits.

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Mounting Instructions

Place the amplifier in the installationlocation. Use a pen or pencil to mark thefour mounting screw hole locations. Setthe amplifier aside and drill the holes forthe mounting screws. (Note: If thesurface you are mounting the amp to iscovered with carpeting or upholstery, cuta small "x" in the material at each screwhole location before drilling the holes.This will help prevent tearing orstretching of the material and carpetfibers from being pulled out.) Set theamplifier in position and align themounting holes with the holes previouslydrilled. Put washers on the four sheetmetal screws provided and drive theminto the mounting panel. Tighten thescrews evenly until the unit is solidlymounted.

WiringProper wiring of the GTS100 and theassociated components is extremelyimportant for proper performance andlong term reliability. Using the propertype of wire is very important. If a spe-cific type of wire should be used for acertain application, it will be noted.

All wiring connections should be madeeither by soldering with heatshrink tub-ing insulation or with high quality crimptype insulated connectors installed witha good crimping tool. Soldering crimpconnections is recommended to furtherenhance connection reliability. Neveruse wire-nuts, insulation-displacementconnectors (i.e. ScotchLok type), or"twist and tape" connections. Do notuse electrical tape; it will loosen withage and extreme temperatures. Neverleave bare wire exposed.Route the wiring through the car care-fully. Do not allow wires to lay againstsharp sheet metal edges or any othersurfaces that might wear away or cutthrough the insulation of the wire. Useinsulated strain reliefs, rubber grom-mets and plastic tubing to protect thewires whenever they are run throughsheet metal panels or are placed wherethey might be pulled or damaged.

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13

Typical System Configuration

Power Supply Connections

The power input and remote turn-onwires are connected to the GTS100 viathe power connector on the end of theamplifier. Use the included wire harnessfor connections. In some cases, such asa custom competition installation, youmay wish to make your own custompower harness. The part number of themating connector and terminals is listedin the specifications section of the man-ual, and is a common part available atmany electronics parts retailers. Pleasedo not call JBL for this, we stock onlythe pre-made harness as supplied withthe amplifier.

+12V Battery Wire (Yellow)• Connect the yellow wire directly to +12

volt terminal of the battery.• If it is necessary to extend the power

wire, use 12 gauge or larger wire thatis heat and oil resistant.

• The GTS100 will draw as much as 20-Amps from the vehicle's electricalsystem, enough to overload conven-tional vehicle wiring. Therefore the+12 volt power supply must bedirectly from the positive side of thebattery Do not connect to thevehicle's fuse block or to a wirefeeding other accessories.

• To prevent electrical system damageor fire, a fuse holder and fuse (notincluded, maximum 20A) must beinstalled in the power supply wire, asclose to the battery as possible, andbefore the wire travels through thefirewall or other metal panel.

Ground Wire (Black)• Proper grounding is extremely impor-

tant. It has a significant effect on theoverall performance and noise levelof the system. The ground wire mustbe solidly connected to a major sheetmetal structure of the vehicle. Usuallythe power supply ground wire can beconnected to a sheet metal panelnear the amp mounting location.Scrape all paint and primer off thesheet metal at the grounding point toensure a good electrical connection.Attach the wire to the grounding pointwith a sheet metal screw and lockwasher (preferably a star lockwasher) or a bolt/lock washer/nut set.

• In some vehicles, such as those thathave non-metal bodies, it may benecessary to extend the power supplyground wire and connect it to a framerail or even directly to the negative (-)terminal of the battery. Use heat andoil resistant 10 gauge or largerstranded copper automotive wire andcrimp or solder and insulate the wire-to-wire connections. Keep theextension wire as short as possible.Solder or crimp a terminal on the endof the extension wire and connect it tothe frame or battery terminal.

• When multiple amplifiers are installedin the system, it is often best toground all of the amplifiers and signalprocessors to the same point to pre-vent noise pickup from a ground loop.In some unusual installations thenoise level will be lower if theamplifier or amplifiers are grounded tothe same point that the head unit isgrounded. Use of heavy gauge

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wire for all grounding, even signalprocessors and head units, can alsohelp to minimize possible noise pickup.

Remote Turn-On Wire (Blue withWhite Stripe)Because the JBL GTS100 includesCommon Sense 2-way turn-on circuitry,you have two options for remotelyactivating the amplifier. When using thespeaker level inputs with a head unit thatincludes a BTL power amp it is notnecessary to connect the remote wire.The amplifier will automatically activatewhenever you turn on the head unit. Ifthe head unit is not of the high powerBTL type, Common Sense will not work.You will need to connect a remote wireas discussed below. If you are using theline level inputs follow the remote wireconnections listed below.The remote power control system turnsthe GTS100 off when not in use to pre-vent discharging of the vehicle's battery.When +12 volts is applied to the remotewire the amplifier is turned on. A redLED on the end panel of the amplifierlights whenever the amplifier is on. If thehead unit has a +12 volt automaticantenna or amplifier remote activationwire, connect it to the blue/white wire ofthe GTS100.Some head units have no automaticantenna or power amp activation wire.Other decks have automatic antennawires that are "on" only when the radio isused (the +12 volt signal is off when atape is played.) In such cases, connectthe remote turn-on wire to an unusedaccessory terminal in the fuse block, orany other +12 volt source that is turned

on and off with the vehicle's ignitionswitch. The remote on/off system drawsnegligible current so a relatively small(18 or 20 gauge) extension wire may beused. Be sure to securely crimp or sol-der and insulate the wire-to-wire con-nections.

Audio Input Connections

Line Level Input ConnectionProper wiring between the signalsource, any other components in thesystem and the GTS100 will help tokeep noise levels in the system low.Use high quality, low capacitanceshielded wire. Keep the wire as shortas possible. Do not splice shieldedwires together. Do not run audio signalwires alongside power wires either forthe amp or the vehicle's standardpower wires. When wires are run forlong distances, separate the audio sig-nal wires from power supply wires orvehicle wiring harnesses as much aspossible. When signal wires and powerwires must cross, try to keep them per-pendicular. Avoid routing any wiresnear accessories such as ignition con-trol modules, tachometers, fuel pumpsor fan motors.The line level inputs of the GTS100accept standard phono plugs (alsocalled RCA plugs.) The outputs of mosthead units, equalizers or crossoversalso accept RCA connectors. If anothertype of connector is used, adapters orspecial cables may be needed. Properwire and connectors can be obtainedfrom any JBL authorized installationspecialist.

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NOTE: The GTS100 has a built-in 80Hz lowpass (subwoofer) crossover and a 100Hzhigh pass (satellite) crossover. Be surethe crossover switch is properly set forthe chosen system configuration (See the"Typical Applications" section forsuggestions). If you have any questionsabout how to set this switch, contact yourlocal JBL dealer.

Input-Mode SwitchThis switch is set according to the number ofinput channels connected to the amplifier andthe desired mode of operation. See diagramson pages 7 and 8 and the descriptions belowfor options.Standard Operation - When using theGTS100 as a conventional stereo amplifiersimply connect the preamp-level sourceoutputs directly to the two gold RCAconnectors or connect the head unit speakeroutputs to the speaker-level inputs with theinput mode switch set to "stereo." Whenusing two sources, both the speaker andpreamp-level inputs may be usedsimultaneously. Be sure to maintain left andright channel consistency.Bridged Mode Operation - To select bridgemode operation, set the input mode switch ineither the "R" only or "L+R" position. In the"R" position, signal from the right channelinput is fed to both amplifier channels. In the"L+R" position, the signal from both channelsis summed internally. When using a singleGTS100 for mono mode fed with a stereosignal it is best to use the "L+R" mode. Whenusing a GTS100 for each channel, or whenfeeding a single GTS100 with a mono signalfrom an

outboard crossover, use the "R" mode andconnect your source input to the right channelinput.Simultaneous Stereo + Mono - For thisconnection, the Input Mode switch is left inthe stereo position. Main speakers areconnected normally to the left and rightstereo outputs, and a center-channel orsubwoofer speaker is connected in bridgedmode. Refer to the diagram on page 19 in the"Speaker Connections" section for details.

Speaker Level Input ConnectionsWhen speaker level signal is used to drivethe GTS100, the signal goes into the ampthrough a special four wire harness/connector(see the "Controls and Connectors" section)If extension wires are needed between thehead unit output and the amplifier unit, useconventional speaker wire. Keep the wiringinside the passenger and trunkcompartments and make the wires as shortas possible. All connections should besecurely crimped or soldered and insulatedwith heatshrink tubing.

Use the color code of the input harness wiresand the identification on the radio/tape deckoutput wires to be sure that left and rightchannels are correctly connected and thepositive/negative polarity of each channel isconnected correctly. For example, the leftpositive output of the head unit must be con-nected to the left positive input of theGTS100. The color code for the speaker levelinput harness is as follows:

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Speaker Level Input Color CodesLeft (+): White

Left (-): White with Black StripeRight (+): Gray

Right (-): Gray with Black Stripe

Using Both the Speaker Level Inputand Line Level Input TogetherIn some systems it may be desirable touse both the speaker level inputs andline level inputs simultaneously. Forinstance, if you have a stock head unitin your car you may connect thespeaker-level inputs of the head unit tothe GTS100. You may simultaneouslyconnect a CD player equipped withpreamp volume control to the preamp-level inputs of the GTS100. TheUniversal Interface circuitry of theGTS100 will isolate the inputs from eachother while mixing both signals.Therefore switching from one source tothe other is as simple as turning theunused source off, and turning thedesired source on. No other switches orrelay boxes are needed.When using this setup it is also possible,using the wiring setup shown below, toallow either of the two sources toremotely turn on the amplifier. This isnot necessary if the factory radio is ofthe high power BTL type and is con-nected to the speaker level inputs. TheCommon Sense turn-on circuit will acti-vate the GTS100 when a poweredsource is used, and the conventionalremote connection of the preamp-levelsource will activate the amp when it isused.

Speaker ConnectionsWhen connecting speaker wires, be surethat no uninsulated wire remains exposedand no loose strands of wire touch eitheran adjoining wire, terminal or a metalsurface. Securely crimp or solder allconnections and insulate them withheatshrink tubing.Use high quality 18 gauge or largerspeaker wire for the amplifier to speakerconnections. Larger wire or special highperformance speaker cables mayimprove the performance of somesystems.Be very careful when speaker wire isrouted through a door hinge area to doormounted speakers. Use grommets andstrain reliefs wherever necessary toprevent damage to the wires.The proper speaker connection dependson whether the GTS100 is used bridgedor stereo. The speakers are connected tothe amplifier with the included wireharness. If you wish to purchase the rawconnector to make a custom-lengthharness, the part number is listed in theSpecifications section. This item iscommonly available from local electronicparts distributors.

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Please do not call JBL for this part; westock only the harness assemblies assupplied with the amplifier.To get proper bass response and stereoimaging, all the speakers in the systemmust be "in phase." The inputs terminalsof the speakers will be marked in someway to identify positive and negativepolarity. Make sure that the positive (+)speaker terminal is attached to thepositive (+) amplifier connection in everyspeaker-to-amp connection. All twoconductor speaker wire has oneconductor marked in some way so it canbe easily traced.The speaker output wire harness colorcodes are listed below:Speaker Output Color Codes

Left (+): WhiteLeft (-): White with Black Stripe

Right (+): GrayRight (-): Gray with Black Stripe

Stereo Connection - Connect eachspeaker directly to the speaker outputharness according to the color-codelisted above. The input-mode switchshould be set to "STEREO"Bridged-mode Connection - Connect theloudspeaker positive (+) terminal to theRIGHT channel positive wire (Gray).Connect the loudspeaker negative (-)terminal to the LEFT channel negativewire (White with Black stripe). The input-mode switch should be set to "R"or"L+R".Simultaneous Stereo + MonoConnection-The GTS100 may be usedto drive a stereo pair of speakers with amono (bridged) speaker at the

same time. This is sometimes used forcenter-channel applications or for inex-pensive subwoofer addition, essentiallycreating a 3-channel system. However,unlike a true bi-amplified subwooferconnection, this system configurationdoes not provide for control of sub-woofer-satellite balance, it requires theuse of a passive subwoofer crossoverinstead of the superior active circuitryalready built-in to the GTS100, and itdoes not separate the power ampsdriving the satellites from the ampsdriving the subwoofer. Therefore thisconnection is best used for addition of acenter-channel, or as an interim step asyou build up to a true bi-amplifiedsubwoofer-satellite system. Connect themain pair of stereo speakers as in thestereo mode, connect the mono speakeras described above for bridge-modeconnection (see diagram on page 19).For use in center channel applications, ahigh-power "L-Pad" or power fader canbe used to attenuate the center channelfor proper level matching. Forsubwoofer-satellite use, connect a non-polarized capacitor in series with eachmain speaker, and a high-powerinductor (coil) in series with thesubwoofer. Your authorized JBL dealerwill help you choose the correct valuesfor your particular components. Theinput-mode switch should be set to"STEREO".

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Simultaneous Stereo-Mono Connection Diagrams

Center Channel Bridged SpeakerConnection

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OperationBefore operating the GTS100, recheck allwiring connections to make sure they arecorrect and secure. Be sure that a 20 ampfuse (not included) is installed in the +12Vline next to the battery. Reconnect thenegative ground (-) terminal of the battery.Make sure that the input mode selector,crossover switch and preamp mode switchare properly set.

Gain AdjustmentsThe setting of the gain control on the GTS100is important to ensure proper performance,low noise levels, and maximum reliability inthe system. As a general rule, controls oncomponents at the front-end of the system(Source, equalizers, electronic crossovers,etc.) should be set as high as possible, withthe amplifier gain control set as low aspossible while still providing adequate volumelevels. Using a high signal level from thesource and a low gain setting on the amplifierwill help keep background noise levels in thesystem low.To adjust a system using a single amplifier,start with the amplifier input sensitivitycontrols fully counterclockwise. Someradio/tape decks have additional output levelcontrols or switches. Set those to theirmaximum position. Set the level controls onany associated equipment such as equalizersand electronic crossovers to the maximumposition or as recommended by themanufacturer. Set all Bass/Treble orequalizer controls to their centered orbypassed positions. While listening

carefully to the system output, adjust thevolume control of the radio/tape deck to thepoint where you first begin to hear audibledistortion. Reduce the level just to the pointwhere the distortion goes away. This is themaximum undistorted output level of yourhead unit and signal processors, and shouldnot be exceeded during use. If audibledistortion does not occur, continue toincrease the level until the head unit is turnedall the way up. If this setting does not provideadequate volume levels, gradually increase(turn clockwise) the gain control of theGTS100 until the system plays as loud asnecessary or when the first signs of distortionare heard.When multiple amplifiers are used in thesystem, it is best to adjust the gain of theamplifier driving the main (usually front)speakers first. Then turn down the head unit'svolume control to a comfortable level, andadjust the remaining amplifiers for the desiredsystem balance. You will find this easiest todo by adjusting the amplifiers in the followingorder: 1) front-channels, 2) rear-channels, 3)subwoofers. Complex systems incorporatingtri-or quad-amplification can be timeconsuming to adjust. Your local authorizedJBL installation specialist is the best personto help with such adjustment.

Other CharacteristicsTurn-On Delay - When installed as describedin this manual, the GTS100 will turn on andoff with the head unit or the vehicle's ignitionswitch. When the amplifier is turned on, thereis a time delay of several seconds (longer incold

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weather) before the amplifier will pro-duce sound. This eliminates the chanceof annoying noises produced by theradio or signal processors being ampli-fied and passed to the speakers whenthe system is first turned on.Power Consumption - Operating theGTS100 when the vehicle is not runningmay discharge the battery. Under nor-mal operating conditions, the units willdraw an average of 5 amps from thebattery. At high volumes, the amplifiercan draw as much as 20 amps for briefbursts. After even a short period of time,this current drain can discharge thebattery to the point that it will not startthe vehicle. Power consumption under"no signal" conditions is less than 1 ampfor the GTS100. Even this small powerusage can discharge a battery overseveral hours time. When the GTS100 isturned off, there is no current drawnfrom the battery despite the direct-to-battery power connection.Overload Protection - The GTS100incorporates elaborate protection cir-cuitry to prevent damage to the amplifiercircuitry and ensure reliable operation.This circuitry will turn the amplifier off inthe event of overheating, a short circuiton the speaker output wiring, orimproper power supply connections. Ifthe amplifier cycles on and off, or doesnot work at all, a problem in installationor an abnormal electrical condition isindicated. Check speaker wiring for shortcircuits or impedance loads significantlybelow 2 ohms, (4 ohms in bridgedmode). Check the power supply voltageat the input of the amplifier to be surethat it is normal, between 11

and 16 volts. Check that the powerwires are not reversed.If the GTS100 is operated at very highpower levels in a high ambient tempera-ture situation, the unit may not be ableto radiate all the heat generated by suchoperation. If the temperature of theamplifier reaches a level that couldcause damage, the thermal overloadprotection circuit will turn the amplifieroff. It will turn the amp back on againwhen it cools off. Repeated activation ofthe protection circuits indicates that thesystem is being improperly operated orthat the amplifier should be relocated toan area that either has a lower ambienttemperature or that allows more air cir-culation around the unit.Fuse Replacement - If the fuse on theGTS100 must be replaced, DO NOTuse a fuse rated for higher current lev-els. The fuse size for the GTS100 is 20amps. Exceeding the standard fuse sizeor bypassing the fuse holder will voidthe warranty and may cause seriousdamage. It is extremely rare for this fuseto blow. If it blows repeatedly, it is mostlikely that the amplifier has an internalproblem that will need to be repaired byan authorized service center. The onlyexternal cause for this fuse to blow isreversed polarity of the power wireconnections.

Solving Noise ProblemsThe power supply system of every vehi-cle has some electrical "noise" that isgenerated by the ignition system, thealternator, the accessories, and theirwiring. High performance audio equip-

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merit is more likely to pick up such noisethan conventional equipment because ithas wide frequency bandwidth and highgain (amplification) circuits. TheGTS100 has built-in power supply filtersto help prevent noise problems. If noiseoccurs it is probably the result ofimproper installation. The followingsuggestions will help you eliminate mostnoise problems.Source Noise - Often noise in a systemis picked up by the signal source. Beforeattempting to eliminate noise from the"amp" be sure it is not being picked upby the signal source and then passed onto the amp. To do this, connect thesignal source output to an externalamplifier which has no other connectionto the vehicle except for the audio signalleads. A battery-powered portable withline-inputs works well for this. Listen tosee if the noise is present in the signalfrom the source unit. If so, consult themanufacturer of the source unit, or yourJBL dealer, for help in eliminating thisnoise. If there is no noise in this signal, itcan be eliminated as the source of thenoise in your system.Ground Loops - The vast majority ofnoise problems in car audio systems arecaused by inadequate or impropergrounding. The head unit, the amplifierand any other components must begrounded to a major metal member ofthe vehicle's frame. Make sure tochoose a solid metal ground point. Inmany new vehicles some structural ele-ments are made of plastic.Although not usually necessary, practi-cal experience shows that often thenoise level in the system will be lower if

the amplifiers and signal processors areall grounded to the same point on thechassis. Usually the head unit does notneed to be grounded to the same pointas the rest of the system, but in someinstances grounding the head unit to thesame point will also help. If this doesnot adequately reduce the noise level,try another ground point on the carframe. Some ground points may workbetter than others. In some instanceswith plastic-bodied vehicles, groundingthe source unit and/or amplifier directlyto the battery will provide the bestresults, although, usually, this providesthe worst results with most cars.In complex systems involving compo-nents from different manufacturers, ithelps to know the type of power sup-plies used in each component. For low-level signal processors such asequalizers or electronic crossovers, amanufacturer may either use a powersupply which is isolated through a DC-to-DC converter, or a simple regulatedsupply from the +12V vehicle battery.Components using the latter type ofsupply can be identified by a direct con-nection from power ground to the shieldof the RCA jacks (measured with noother connections present). For thesecomponents, the best ground connec-tion may be one where the powerground wire is not connected at all! TheRCA cables will provide the groundconnection to the source unit. Pleasenote that this is only appropriate forunits which draw less than 500mA ofcurrent. Higher power units of this typeare best connected with their ground

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wires connected directly to the chassisof the head unit. The trickiest groundingtask is created when some componentsof this type are mixed with other compo-nents using isolated supplies. For thistype of system, the following groundingscheme will usually work:1. Connect the head unit chassis to asolid vehicle ground using a short, heavygauge wire (>AWG10). Do not connectthis to the vehicle's wiring harness, butgo directly to a metal part of the vehicle.2. Connect all non-isolated signal-processor grounds directly to the headunit chassis at the same point. Run eachwire individually. Due to wire resistanceconnecting multiple wires to a singlewire, then running the single wire to thehead unit, is not the same!3. Connect all amplifier and isolatedsignal processor grounds directly to thevehicle chassis at the same point aseach other, but not necessarily to thesame point as the head unit. Power-lineNoise - The built-in power supply filter ofthe amplifier makes external filtersunnecessary. In some cases, powersupply noise can enter the systemthrough the head unit power supply orthe supply of an equalizer or other signalprocessor. Putting a filter on the headunit or signal processor power supplyinput may then be helpful.Power wires carrying high currents mayinduce noise in nearby signal wires.Make sure that power wires and signalwires do not run together for long dis-tances. When power and signal leads

must cross, they should cross at rightangles. If you suspect that power linenoise is being induced in the signalleads, you can repeat the test for sourcenoise described previously, but performthe test at the amplifier end of the signalcables.Other Noise Sources - Common noiseproblems will be solved by propergrounding and power supply connec-tions. However, there are many noisesuppression devices (such as sparkplug and coil lead suppressors and rotorand coil bypass capacitors) available atauto parts or car stereo stores. Thereare also noise suppressors that can beconnected directly to the alternator thatare effective in some situations. The useof any such suppressors should bediscussed with a JBL authorizedinstallation specialist. Certain vehiclesare particularly "noisy," especiallymodels that have solid state ignitionsystems or that have non-metal bodies.Such vehicles may require electricalnoise suppression devices which are notnormally needed.Antenna - A common noise problem isgenerated by a "ground loop" producedby the antenna shielded cable beinggrounded at both the antenna mountingpoint and at the head unit input. In thisinstance, insulate the antenna groundfrom the chassis of the vehicle at theantenna mounting point so the antennashield is grounded only at the radio'santenna input. Commercial antennaground-loop isolators are also available.Switching Noise - The GTS100 has ahighly developed switching power sup-ply which generates some RF interfer-

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ence as a result of its switch-mode operation.Although this is internally filtered andshielded by the GTS100 chassis, someunusually sensitive installations may pick upswitching noise, especially when listening toweak AM radio stations. If this unusual situa-tion occurs, one of the following installationcorrections will typically eliminate theproblem. 1) Relocate the amplifier to aposition farther away from the radio or radioantenna. 2) Move the electrical ground of thehead unit and/or amp to a different point onthe vehicle's chassis. 3) Keep the amplifierpower supply wiring away from the radio orantenna wiring. 4) Wrap the +12 volt powersupply wires for the radio/tape deck withmetallized shielding tape or ground braid andground the tape to the chassis of the vehicle.

Additional SystemConfigurations for Add-On orUpgradeThe features and capabilities of theGTS100 provide tremendous systemdesign flexibility. The diagrams on thefollowing pages illustrate some of the •system possibilities. They are in orderof increasing complexity, showing theway a system may be upgraded inlogical steps. Although the systems areshown using speaker-level connectionfrom the head-unit, they may be builtusing any combination of speaker orpreamp level inputs, depending on thecapability of your head unit. (Seepages 25-26.)

MaintenanceThe GTS100 does not require any regularmaintenance. Periodically checking the mainpower supply and grounding points and terminalconnections is advisable. Be sure the connectionsare solid and corrosion-free. Loose or corrodedconnections can cause annoying intermittent noiseor unusual operational problems. Do not allow dustto accumulate on the amplifier heat sinks. It willreduce the amplifier's ability to dissipate heat.Occasional vacuum cleaning will prevent dustaccumulation.

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System 1Add Power to Main Speakers

Add a GTS100 to the main(usually front) outputs of anexisting head unit. Secondaryspeakers (usually rear-fill)connect to the head unit'sinternal amplification.Next Step:Add a second GTS100 toamplify the other set ofspeakers or a subwoofer (seeSystem 2).

System 2AAdd a Subwoofer (Active)

Use the GTS100 to drive 1 or 2subwoofers with the head unitpowering the main speakers.This is an excellent way toupgrade a good stock system.Next Step:Add power to Front Full-RangeSpeakers (see system 3).

System 2BAdd a Subwoofer (Passive)

Use the GTS100 inSimultaneous Stereo + Monomode to drive main speakerswith subwoofers A passivecrossover is needed for this asdescribed on page 18.Next Step:Add a second GTS100 to powersubwoofers and main speakersindividually (see system 3).

System 3 ^^^^~ Add aSecond GTS100Get more power andsystem control by addinga second GTS100 topower the main speakersand subwoofersindividually. Use the built-in crossover to high-passthe front speakers andlow-pass , thesubwoofers. Next Step:Add power to the RearFull-Range Speakers.Note: For Non-Fadingbass, also connect therear-channel head unit ,speaker output to thespeaker level input of thesubwoofer GTS100.

System 5

Add a Second Subwoofer AmplifierFor the ultimate in bass output, add a second subwoofer amplifierfor a total | system power of 340 Watts RMS!Note the cross-linking of preamp inputs for the two subwooferamplifiers to provide non-fading bass.Next Step:Add additional amplifiers in bridge-mode to the front and

rear main speakers. Then add electronic crossovers and biampfront and rear speakers.

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System 4 ^™"'^^—

Add Power to the RearAdd an amp for the rearspeakers for higher volumecapability and more control.Next Step:Add more subwoofer power

In Case of DifficultyPower-on light does not come on.

Remote-on light is illuminated, but nosound is heard from some or all of thespeakers.

Head unit not on; turn the head unit on.Ground wire is disconnected or defective;check for continuity with an ohmmeterbetween the GTSIOO's ground terminal anda known chassis ground point.Battery wire is disconnected or defective;check for approximately +12 volts betweenthe GTSIOO's Battery and Groundterminals.Blown fuse; check the GTSIOO's 20 ampfuse located on the endpanel near the powerconnector. If it is blown replace it with anidentical one. If the new fuse blowsimmediately, then check all the wiringconnections. If no fault is found, consult yourJBL dealer.Remote-on wire between the head unit andthe GTS100 is disconnected or defective;check for +12 volts between the GTS100remote on wire and the ground wire with thehead unit on.Head unit connected to speaker-level input isnot BTL high-power type and no remote wireis connected; connect remote turn-on wire toswitched +12V source.Incorrect switch settings; make sure that allswitches (input mode, line, and crossover)are in their correct positions for your systemconfiguration.Incorrectly connected or shorted speakerwires; check for shorts in wiring.

Defective or disconnected audio cables;check for continuity and replace ifnecessary.

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(continued)Remote-on light is illuminated, but nosound is heard from some or all of thespeakers.

Incorrect gain adjustment; verify that theGTS100 gain controls are not turnedcompletely down. If they are, sound outputlevel may be very low and may give theimpression that the system (or part of thesystem) is dead.

Defective head unit or signal processor;check each component for proper wiring andoperation.Defective GTS100; If there is audio signalpresent at the inputs of the GTS100 andthere is no output, the GTS100 may bedefective.

Alternator whine through the audiosystem with the engine running. • Ground loops; Follow the wiring suggestions in

the section called "Solving Noise Problems."Also, verify that the chassis grounding pointyou have chosen is true ground by checkingfor continuity between the chassis groundpoint and battery ground.

Bass output from speakers too low.• Speaker wired out of phase; check for proper

polarity on all speaker wiring (+ ampterminal to + speaker terminal and - ampterminal to - speaker terminal.

If you want to talk to us about any problems, call JBL Customer Service at 1-800-336-4JBLBetween 9AM and 5PM Eastern time.

Specifications

35 watts x 2 Continuous Power Output(4 Ohms, 0.05% THD) (20Hz - 20kHz, 50 watts x 2 14.4V Battery Voltage)(2 Ohms, 0.08% THD)100 Watts x 1 ——————— (4 Ohms, 0.08% THD)

Signal to Noise Ratio 100dBAFrequency Response 10Hz - 50kHz (+0, - 1dB) 20Hz- 20kHz(+0,-0.1dB)

Damping Factor >200Line Level Input Sensitivity 100mV - 4V RMS (5OOmV nominal) (for ratedpower)

Line Level Input Impedance 10k Ohms

Speaker Level Input Impedance 15 Ohms

Speaker Level Input Sensitivity 200mV - 8V RMS (1V nominal)

Preamp Output Sensitivity 2V Out for 4V Speaker Level Input

Minimum Speaker ImpedanceSingle Ended, Non-Bridged 2 OhmsBridged 4 Ohms

Built-in Electronic Crossover 80Hz, 18dB per octave Low Pass Filter Frequencyand Slope 100Hz, 18dB per octave High Pass FilterPower Requirement 11 to 16V DC Negative Ground Fuse Size

20 Amp ATC Type Fuse

Size (L x W x H) SVe" x 9'/4" x 2"(168.3mm x 235.0mm x 50.8mm)

Weight 4lbs. 3oz. (1.90kg)Speaker Input / Output Mating Molex Mini-Fit Jr. # 39-01 -2040Connector Metal Pins: 39-00-0038

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Power Mating Connector Plastic Housing: AMP #1-480700-0Metal Pins for Ground & +12V: AMP # 350923-3Metal Pins for Rem. In: AMP # 350536-1