10
Bass BOOst
The Bass Boost control provides up to 12dB of bass boost at 45Hz. Set this control according to your personal taste,
but be careful not to set the control at a high enough level to cause audible distortion or bottoming of your subwoofer.
pOWer/prOtectiOn led
Power/
Protection
LED
The GTO amplifier Power/Protection LED’s color indicates the amplifier’s operational status:
LED is orange: Normal operation (power is on)
LED is off: Amplifier is in standby mode
LED is red: Amplifier is in protect mode
If the amplifier is in the protect mode (the LED is red), see
Troubleshooting,
below.
TrOubleshOOTinG
If your amplifier isn’t performing the way you think it should, check to see if the problem is covered in this section
before calling your dealer or contacting JBL customer service.
prOBlem
causes and sOluTiOns
No sound (the amplifier’s
Power/ Protection LED is off):
• Check that the amplifier’s +12V and GND connections have been properly
made.
• Check if the fuse on the +12V wire located near the battery is blown; if so,
replace it with an identical fuse.
• Check all amplifier fuses; if any are blown, replace them with identical fuses.
• If you are using the amplifier’s REM connection for turn-on, check that the
wire is properly connected to the audio system’s remote turn-on wire or to the
vehicle’s ACC power terminal.
• If you are using the amplifier’s Auto Turn-On circuit for turn-on, check that the
amplifier’s Auto Turn-On switch (on the amplifier’s bottom panel) is set in the
“On” position.
No sound (the amplifier’s
Power/ Protection LED is
orange):
• Check that all amplifier input and speaker connections have been properly
made.
• Check that the amplifier’s Gain controls are not turned all the way down.
• Check that the vehicle audio system’s source unit’s volume control is not
turned all the way down.
No sound (the amplifier’s
Power/ Protection LED is red):
• Confirm that the vehicle’s electrical system is supplying between 9V and 16V
DC to the amplifier. If the supply voltage is outside of this range, correct the
condition before attempting to use the amplifier.
• If the amplifier has overheated, wait until it has cooled down before attempting
to use it again.
• Disconnect all speakers from the amplifier and attempt to turn it on again:
– If the amplifier turns on (the Power/Protect LED is orange), there is a short
circuit in one or more of the speaker wires. Correct all short circuits before
reconnecting the speakers to the amplifier.
– If the amplifier does not turn on (the Power/Protect LED is still red), contact
your authorized JBL dealer for assistance.