“Status” LED / Protection Circuitry
There is a single multi-color LED on the
control panel of the amplifier to indicate the
amplifier’s operating status. This LED’s behavior
is as follows:
1)Flashing Green: amplifier is powering up, audio output is muted.
2)Constant Green: amplifier is on and functioning normally, audio output is active.
3)Constant Red: lights to indicate that the amplifier has exceeded its safe operating temperature, putting the amplifier into a self-protection mode, which reduces the peak power output of the amplifier. The red light will turn green and the amplifier will return to full-power operating mode when its temperature returns to a safe level.
3)Constant Amber (yellow): lights to indicate that the impedance of the speaker load connected to the amplifier is lower than the optimum load impedance range for the amplifier. When this light is on, a protection circuit engages and reduces the power output of the “Front” or the “Rear” channels, depending on which channel is experiencing the problem. The amber indicator will also light when a short-circuit is detected in the speaker wiring (this can be a short between the positive and negative speaker wires or between either speaker wire and the vehicle chassis). This can be used to diagnose a short-circuit by only connecting one of the amplifier sections at a time (“Front” or “Rear” channels). The amber LED will light when you connect the section that is experiencing the problem and turn the volume up.
4)Alternating Red and Green: lights to indicate that the amplifier is experiencing a fault that may require service of the amplifier, its wiring or the vehicle’s charging system. Audio is muted when this fault occurs. The most likely cause of this fault is a low supply voltage condition. If battery voltage drops below 8.5 volts at any point, the amplifier (except for the
“Status” LED) will shut itself off to protect itself and the vehicle’s charging system. If the voltage drops below 6 volts, the “Status” LED will also turn off.
The amplifier will turn back on automatically when voltage climbs back above 9 volts. This shut-down and turn-on behavior may happen in a rapid cycle when bass-heavy program material causes a weak charging system to momentarily dip too low. If this is happening in your system, have your charging system inspected to make sure it is working properly.
If no problem is found with the supply voltage to the amplifier and you are still seeing alternating Red and Green on the “Status” LED, it is likely that the amplifier is suffering from an internal fault that requires factory service.
For more information on troubleshooting this amplifier, refer to Appendix D (pages 20, 21).
There is only one condition that will shut down an undamaged HD600/4 completely…
If battery voltage drops below 10 volts, the entire amplifier will shut itself off to protect itself and the vehicle’s charging system. The “Status” LED will turn off when this occurs. The amplifier will turn back on when voltage climbs back above 11 volts. This may happen in a rapid cycle when bass-heavy program material causes a weak charging system to dip below 10 volts momentarily. If this is happening in your system, have your charging system inspected to make sure it is working properly. For information on troubleshooting this amplifier, refer to Appendix D (pages 20, 21).
Servicing your JL Audio Amplifier
If your amplifier fails or malfunctions, please return it to your authorized JL Audio dealer so that it may be sent in to JL Audio for service. There are no user serviceable parts or fuses inside the amplifier. The unique nature of the circuitry in the JL Audio amplifiers requires specifically trained service personnel. Do not attempt
to service the amplifier yourself or through unauthorized repair facilities. This will not only void the warranty, but may result in the creation of more problems within the amplifier.
If you have any questions about the installation or setup of the amplifier not covered in this manual, please contact your dealer or technical support.
JL Audio Technical Support:
(954) 443-1100
9:00 AM – 5:30 PM (Eastern Time Zone)
Monday - Friday
Appendix A:
HD600/4 Specifications
Amplifier Topology: Class D, switching type with patented Single-Cycle Control™ technology. Power Supply: Pulse width modulation-regulated switching power supply
Recommended Fuse Value / Type: 50A (AFS, AGU or MaxiFuse™)
Rated Power (Stereo):
150W RMS x 4 @ 1.5-4Ω (11V - 14.5V) Rated Power (Bridged):
300W RMS x 2 @ 3-8Ω (11V - 14.5V)
THD at Rated Power: <0.03% @ 4Ω per channel (Average at 1 kHz)
Signal to Noise Ratio (20 kHz Bandwidth): Referred to Rated Power: 110 dBA Referred to 1 Watt: 88.2 dBA
Frequency Response: 6 Hz - 30 kHz (+0, -1dB) Damping Factor:
300 @ 4Ω per ch. / 50 Hz
150 @ 2Ω per ch. / 50 Hz
Crossover Filters:
Filter Sets: Two (Front Channel and Rear Channel)
Filter Type: State-variable, 12 dB/octave Butterworth or 24 dB/octave Linkwitz-Riley
Filter Modes: Low-Pass or High-Pass, Defeatable.
Cutoff Freq. Range: Continuously variable, 50 - 500 Hz
Input Sections:
No. of Inputs: Two Stereo Pairs (Front and Rear)
Input Type: Differential-balanced with RCA jack inputs
Input Range: Switchable from 200mV - 2V RMS (Low) to 800mV - 8V RMS (High)
Preamp Output:
2-Channel, buffered pass-through type, switch-selectable to pass signal from “Front” inputs only, or from all four inputs (summed).
Chassis Dimensions (LxWxH):
10.74in. x 7.85 in. x 1.93 in. (273 mm x 199.5 mm x 49 mm) Dimensions do not include connectors.
