JBL GTS300, GTS600 manual Input Gain Adjustment

6. Input Gain Adjustment

Before operating the GTS300 or GTS600, recheck all wiring connections to make sure they are correct and secure. Be sure that a fuse (40 amp for GTS300 and two 40 amp fuses for the GTS600, not included) is installed in the +12V line near the battery. Reconnect the negative ground (-) terminal of the battery. Make sure that the input mode selector, speaker output crossover frequency modules, and preamp output crossover switch are properly set.

Adjusting the Gain

•The setting of the gain control on the GTS300 and GTS600 is important to ensure proper performance, low noise levels, and maximum reliability in the system.

Using a high signal level from the source and a low gain setting on the amplifier will help keep backgroune noise levels in the system low.

•To adjust a system using a single amplifier, start with the amplifier gain controls fully counterclockwise.

Set all Bass/Treble or equalizer controls to their centered or bypassed positions. While listening carefully to the system output, adjust the volume control of the radio/tape deck to the point where you first begin to hear audible distortion. Reduce the level just to the point where the distortion goes away.

If this setting does not provide adequate volume levels, gradually increase (turn clockwise) the gain control on the GTS300 ot GTS600

until the system plays as loud as necessary ot when the first signs of distortion are heard.

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