JBL Marine A758, A1504 4 Channel Amplifier Owner’s Manual

: July 8, 2024
: JBL

Table of Contents

WHAT’S IN THE BOX
ACCESSING CONNECTORS AND CONTROL PANEL
WIRING FOR POWER AND GROUND
WIRING FOR INPUT SIGNAL
WIRING FOR OUTPUT
SETTING GAIN, CROSSOVERS, AND BASS BOOST
SPECIFICATIONS
Safety Instruction and Warranty Card
WARRANTY CARD
LIMITED WARRANTY
References
Read User Manual Online (PDF format)
Download This Manual (PDF format)

**JBL Marine A758, A1504 4 Channel Amplifier Owner’s Manual

**

WHAT’S IN THE BOX

Marine A758

Marine A1504

ACCESSING CONNECTORS AND CONTROL PANEL

Pry off trim piece
Slide the panel cover down
Remove panel cover

MOUNTING THE AMP

Note: It is recommended that you make all wire connections before permanently mounting the amplifier.
IMPORTANT: Disconnect the negative (–) battery terminal of the accessory battery before beginning the installation.

Always wear protective eyewear when using tools.
Choose a safe mounting location. Check clearances on both sides of a planned mounting surface. Be sure that screws or wires will not puncture the vessel hull, fuel lines, or wiring harnesses, and that wire routing will not interfere with the safe boat operation. Use caution when drilling or cutting in the mounting area.
Choose a location that provides enough air circulation.
Do not mount the amplifier with the heat sink facing downward, as this interferes with cooling.
Mount the amplifier so that it will not be damaged by the feet of passengers or shifting cargo.

WIRING FOR POWER AND GROUND

At amplifier:

Remote turn-on to aftermarket stereo REM out (used only with low-level signal inputs)

At ground location:

WIRING FOR INPUT SIGNAL

A758 low-level signals – 2-channel input

From stereo front low-level outputs
Note: when using 2-channel low-level signals and remote turn-on lead, set the INPUT LEVEL switch to LO, the TURN-ON MODE switch to REM, and the INPUT MODE switch to 2 CH.

A758 low-level signals – 4-channel input
From stereo front low-level outputs

From stereo rear low-level outputs
Note: when using 4-channel low-level signals and remote turn-on lead, set the INPUT LEVEL switch to LO, the TURN-ON MODE switch to REM , and the INPUT MODE switch to 4CH.

A758 low-level signals – 8-channel input
From source unit low-level outputs
Note: when using 8-channel low-level signals and remote turn-on lead, set the INPUT LEVEL switch to LO, the TURN-ON MODE switch to REM, and the INPUT MODE switch to 8CH.

A1504 low-level signals
Note: when using low-level signals and remote turn-on lead, set the TURN-ON MODE switch to REM and the INPUT LEVEL switch to LO.

High-level input signals – Preparing adapters

A 758 high-level input signals – 2-channel input
Stereo front speaker wires

Note: when using 2-channel high-level signals, set the INPUT LEVEL switch to HI, the TURN-ON MODE switch to DC, and the INPUT MODE switch to 2 CH.

A758 high-level input signals – 4-channel input
Stereo front speaker wires

Stereo rear speaker wires
Note : when using 4-channel high-level signals, set the INPUT LEVEL switch to HI, the TURN-ON MODE switch to DC, and the INPUT MODE switch to 4CH.

A758 high-level input signals – 8-channel input
Stereo speaker wires
Note: when using 8-channel high-level signals, set the INPUT LEVEL switch to HI, the TURN-ON MODE switch to DC, and the INPUT MODE switch to 8CH. Note: when using high-level signals, set the “TURN-ON MODE” switch to “DC” and the “INPUT LEVEL” switch to “HI1”. If no sound plays, change the “INPUT LEVEL” switch to “HI2”.

WIRING FOR OUTPUT

Note: Be sure to observe proper speaker polarity.

A758 8-channel output
A758 7-channel output

A758 6-channel output
A758 4-channel output
A1504 4-channel output
A1504 3-channel output
A1504 2-channel output

SETTING GAIN, CROSSOVERS, AND BASS BOOST

Setting the gain

Start with GAIN control set to minimum, and the crossover control rotated midway.
For the front and rear channels, choose music you’re familiar with. For the sub woofer channel on the Marine A758 or A1504, choose music with substantial bass content.
Turn the volume control on your receiver to 3% of its total output.
Adjust the GAIN control clockwise, listening carefully to the bass output. If you hear distortion, turn the GAIN control counterclockwise to decrease the gain.
GAIN

Selecting the crossover mode
On the front and rear channels, you can select your preferred crossover mode.

Choose HPF to allow only frequencies above a certain point to reach your speakers. Recommended if you’re using a sub woofer in your system, as it keeps low base from your full-range speakers.
X-OVER

Choose LP F to allow only frequencies below a certain point to reach your speakers. Recommended if you’re bridging the front or rear channels to power a sub woofer. Choose FULL to allow all frequencies to reach your speakers. Recommended if you’re not using a sub woofer in your system.

Selecting the crossover frequency
Choose the crossover point to suit listening preferences. Turn the dials to the left to lower the crossover point and to the right to raise the crossover point. Exact crossover settings for coaxial speakers and sub woofers depend on your listening preferences.
FREQ

SPECIFICATIONS

| Marine A758| Marine A1504
---|---|---
Power output @ 4 ohms (14.4V)| 75 watts RMS x 8| 150 watts RMS x 4
Power output @ 4 ohms (12.8V)| 65 watts RMS x 8| 130 watts RMS x 4
Power output @ 2 ohms (14.4V)| 125 watts RMS x 8| 225 watts RMS x 4
Power output @ 2 ohms (12.8V)| 100 watts RMS x 8| 200 watts RMS x 4
Power output in bridged mode @ 4 ohms (14.4V)| 250 watts RMS x 4| 450 watts RMS x 2
Power output in bridged mode @ 4 ohms (12.8V)| 200 watts RMS x 4| 400 watts RMS x 2
Frequency response| 20-20,000 Hz| 20-20,000 Hz
Crossover frequencies| 32-320 Hz variable,12 dB/ octave| 32-320 Hz variable,12 dB/octave
Line-level input sensitivity| 200mVrms – 5Vrms| 200mVrms – 5Vrms
High-level input sensitivity| 1Vrms – 25Vrms| 1Vrms – 25Vrms
Signal-to-noise ratio| 80 dB| 80 dB
THD+N @ rated power| 1%| 1%
Fuse rating| 105A| 105A
Operating voltage| 9 ~ 16VDC| 9 ~ 16VDC
Amplifier class| D| D
Dimensions (W x H x D)| 14-3/16″ x 2-1/16″ x7-1/8″ (360mm x 51.3mm x 180mm)| 14-3/16″ x 2-1/16″ x7-1/8″ (360mm x 51.3mm x 180mm)
Weight| 3.7kg| 3.6kg
Recommended wire gauge (Power)| 4| 4
Maximum operation temperature| 70°C| 70°C
Fuse| 105A| 105A

TROUBLESHOOTING

No audio and POWER INDICATOR is off.

No voltage at BATT+ and/or REM terminals, or bad or no ground Check voltages at amplifier terminals with VOM.

No audio and PROTECT INDICATOR flashes every 4 seconds.

DC voltage on amplifier Amplifier may need service; see enclosed warranty card for service information.

No audio and PROTECT and POWER INDICATORS flash.

Voltage less than 9V on BATT+ Check boat charging system.

No audio and PROTECT INDICATOR is on.

Amplifier is overheated. Make sure amplifier cooling is not blocked at mounting Or, there may be voltage greater than 16V (or less than 8.5V) on BATT+ connection. Check boat charging system.

Amplifier fuse keeps blowing.

The wiring is connected incorrectly or there is a short Check wiring connections.

Distorted audio.

Gain is not set Check setting. Check wires for shorts or grounds. Amplifier or source unit may be defective.

Distorted audio and PROTECT INDICATOR flashes.

Short circuit in speaker or Remove speaker leads one at a time to locate shorted speaker or wire, and repair.

Music lacks dynamics or “punch”.

Speakers are not connected Check speaker connections for proper polarity.

Engine noise—whining or clicking—in system when the engine is on.

Amplifier is picking up alternator noise. First, check ground connection on the amplifier – a loose or improper ground is one of the main causes for Turn down gain. Move RCA audio cables away from power wires. Installing an alternator noise filter on power line between battery and alternator might also be necessary.

Safety Instruction and Warranty Card

PRODUCT REGISTRATION
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Register your product
‘Product registration may not be available for all countries

Download the full warranty card and safety information and other helpful information from our website: www.jbl.com/warrantyandsafetybooks

WARRANTY CARD

SET UP INFORMATION & PRODUCT REGISTRATION

Congratulations with the purchase of your new Product. We have done our utmost to make your experience the best one possible If you have any questions when setting up your Product and would like some helpful hints, we recommend that you visit the relevant country specific support website for your Product: www.jbl.com. There you will also find relevant contact information. If you cannot find the information you are looking for, please contact the vendor that sold the Product to you or contact the relevant JBL, customer support center by electronic mal or phone.
We recommend that you register your Product via the relevant country specific website for your Product Your registration will allow us to inform you about updates for certain products possible new offers and new Products and/or applications. Registering is easy, just follow the instructions on the relevant country specific website for your Product.

NOTE: THIS LIMITED WARRANTY DOES NOT APPLY TO CONSUMERS IN THE EUROPEAN ECONOMIC AREA (EEA) MEMBER STATES AND THE RUSSIAN FEDERATION AS THEY ARE PROTECTED BY LOCAL CONSUMER LAW AND BENEFIT FROM LOCAL STATUTORY WARRANTIES

LIMITED WARRANTY

WHO IS PROTECTED BY THE WARRANTY
This limited warranty (the “Limited Warranty”) protects only the original end- user (“you” or “your”), and is not transferable and is applicable only in the country (excluding EEA member states and the Russian Federation) in which you originally purchased your JBL Product (the “Product”). Any attempt to transfer this warranty shall immediately make this warranty void.

LIMITED WARRANTY
HARMAN International Industries, Incorporated (“HARMAN”) is the manufacturer and through its local subsidiary, warrants to you that the Product (including components provided in/with the Product) will be free from defects in workmanship and materials for a period of ONE year from the date of retail purchase by you (the “Warranty Period”). During the Warranty Period, the Product (including components), will be repaired or replaced at HARMAN’s option, without charge for either parts or labor OR at HARMAN’s sole option, the price of the Product may be refunded, subject to depreciation based on your purchase price for the Product pro-rated over the remaining balance of the Warranty Period. Any warranty service or replacement of parts will not extend the Warranty Period.

HARMAN International Industries, Incorporated 8500 Balboa Boulevard, Northridge, CA 91329 USA www.jbl.com
© 2023 HARMAN International Industries, Incorporated. All rights reserved. JBL is a trademark of HARMAN International Industries, Incorporated, registered in the United States and/or other countries. Features, specifications and appearance are subject to change without notice.
CA_JBL_Marine A758-A1504_OM_US_SOP_V4_online

HARMAN International Industries, Incorporated
8500 Balboa Boulevard, Northridge, CA 91329 USA
516.255/4545 (USA only)
SSA2020 002 JBL Non HP Safety Sheet (150 x 80mm) V4