User manual JBL GTS150

[. . . ] The power amplifier circuitry is a fully discrete design notable for low distortion and unusually clean and clear reproduction quality. Your GT series amplifier will easily connect to virtually any car audio system, whether it is factory installed or purchased separately. In addition to conventional preamp-level inputs, this model features JBL's Universal Interface design, which facilitates simple connection to factory radios with the low distortion that is usually only associated with preamplevel connection. With Universal Interface, a factory radio can be used either as the main music source or combined with a CD changer which includes volume control capability, simultaneously connected directly to the amplifier. [. . . ] In the "R" position, signal from the right channel input is fed to both amplifier channels. In the "L+R" position, the signal from both channels is summed internally. When using a single GTS100x for mono mode fed with a stereo signal, it is best to use the "L+R" mode. When using a GTS100x for each channel, or when feeding a single GTS100x with a mono signal from an outboard crossover, use the "R" mode and connect your source input to the right channel input. Simultaneous Stereo + Mono ­ For this connection, the Input Mode switch is left in the stereo position. Main speakers are connected normally to the left and right stereo outputs, and a center-channel or subwoofer speaker is connected in bridged mode. Refer to the diagram on page 21 in the "Speaker Connections" section for details. Speaker-Level Input Connections When speaker-level signal is used to drive the GTS100x, the signal goes into the amp through a special four-wire harness/connector (see the "Controls and Connectors" section, page 12). If extension wires are needed between the head unit output and the amplifier unit, use conventional speaker wire. Keep the wiring inside the passenger and trunk compartments and make the wires as short as possible. All connections should be securely crimped or soldered and insulated with heatshrink tubing. Use the color code of the input harness wires and the identification on the radio/tape deck output wires to be sure that left and right channels are correctly con- nected and the positive/negative polarity of each channel is connected correctly. For example, the left positive output of the head unit must be connected to the left positive input of the GTS100x. FUSE 20A STEREO + R - + L - LOW + R BRIDGED + L - 20A BAT(+) REM GND POWER Stereo, Non-Bridged Speaker Connection* (+) (­) (­) (+) 4 Minimum 4 Minimum *You may scale the 100Hz values listed to a different desired frequency by using the following formulas: 100 High-Pass: x 300µF = New Capacitor Value desired frequency in Hz 100 Low-Pass: x 6. 2mH = New Inductor Value desired frequency in Hz 22 Bridged-Mode Connection ­ Connect the loudspeaker positive (+) terminal to the RIGHT channel positive wire (Gray). Connect the loudspeaker negative (­) terminal to the LEFT channel negative wire (White with Black stripe). The input-mode switch should be set to "R" or "L+R. " Simultaneous Stereo + Mono Connection ­ The GTS100x may be used to drive a stereo pair of speakers with a mono (bridged) speaker at the same time. This is sometimes used for centerchannel applications or for inexpensive subwoofer addition, essentially creating a threechannel system. However, unlike a true bi-amplified subwoofer connection, this system configuration does not provide for control of subwoofer-satellite balance; it requires the use of a passive subwoofer crossover instead of the superior active circuitry already built into the GTS100x, and it does not separate the power amps driving the satellites from the amps driving the subwoofer. Therefore, this connection is best used for addition of a center-channel speaker, or as an interim step as you build up to a true bi-amplified subwoofersatellite system. Connect the main pair of stereo speakers as in the stereo mode, connect the mono speaker as described for bridged-mode connection (see diagram on page 21). For use in center-channel applications, a high-power "L-Pad" or power fader can be used to attenuate the center channel for proper level matching. For subwoofersatellite use, connect a nonpolarized capacitor in series with each main speaker, and a highpower inductor (coil) in series with the subwoofer. Your authorized JBL dealer will help you choose the correct values for your particular components. The input-mode switch should be set to "Stereo. " Operation Before operating the GTS100x, recheck all wiring connections to make sure they are correct and secure. [. . . ] If the new fuse blows immediately, then check all the wiring connections. If no fault is found, consult your JBL dealer. · Remote-on wire between the head unit and the GTS100x is disconnected or defective; check for +12 volts between the GTS100x remote-on wire and the ground wire with the head unit on. · Head unit connected to speakerlevel input is not BTL highpower type and no remote wire is connected; connect remote turn-on wire to switched +12V source. Remote-on light is illuminated, but no sound is heard from some or all of the speakers · Incorrect switch settings; make sure that all switches (input mode, line, and crossover) are in their correct positions for your system configuration. · Incorrectly connected or shorted speaker wires; check for shorts in wiring. · Defective or disconnected audio cables; check for continuity and replace if necessary. [. . . ]