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Efficient power for your music always set correctly
JBL's compact GTO-804EZ 4-channel amp will drive each of your front and rear speakers with 80 watts RMS, bringing exciting, visceral impact to the music in your car. Or, bridged in 2-channel mode, it can run a couple of subs with up to 200 watts each. This amp looks very cool with its "old-school" styling, and JBL includes a few innovations that really separate this amp from the others.

Simple Setup System for setting amp gain
One of the biggest problems with installing an amplifier is setting the gain properly. JBL has come up with a fool-proof method for getting it right, ensuring full-power performance and distortion-free play. Using test tones on the included setup CD, you adjust the gain knob until the yellow light or the red light goes off, and the green "Gain OK" light comes on — it's that simple. You'll never have to worry again about your amp "clipping" the signal, and possibly damaging your speakers or subs.

Plays well with factory radios
This GTO amp comes with screw-on bare wire-to-RCA adapters that let you hook up the amp, using your car's factory speaker wiring to supply the input signal. In some vehicles, the factory radio shuts down when you try to tap into the speaker wires, displaying a "no speakers are present" message. This amp features a special circuit that fools those factory radios by simulating a speaker load. The onboard crossovers and bass boost let you fine tune the system to perfection, and the large recessed knobs mean you don't need a tiny screwdriver to make your adjustments.

GTO-804EZ input panel

Product Highlights:

  • 4-channel car amplifier
  • 80 watts RMS x 4 at 4 ohms (100 watts RMS x 4 at 2 ohms)
  • 200 watts RMS x 2 bridged at 4 ohms (4-ohm stable in bridged mode)
  • CEA-2006 compliant
  • frequency response: 20-23,000 Hz
  • Class AB amp technology
  • variable low- and high pass filters (40-220 Hz, 12 dB/octave)
  • variable bass boost on rear channels (0-12 dB at 45 Hz)
  • Simple Setup System with test tone CD for perfect gain setting
  • routing switch for 2-channel sources
  • preamp outputs
  • preamp and speaker-level inputs (speaker wire-to-RCA adapters included)
  • switchable automatic signal-sensing turns on amp without need for remote lead
  • fuse rating: 25A x 2
  • 8-gauge power and ground leads recommended — wiring and hardware not included with amplifier
  • 11-15/16"W x 2-5/8"H x 9-11/16"D
  • warranty: 1 year
  • Our 60-day money-back guarantee

My system has plenty of power. Who needs an amp?

You might think you don't need an amp because you have a 400-watt system in your car, or because your new stereo puts out 50 watts a channel. But those are peak wattage ratings, which may boil down to 15 or 20 watts per channel, using the more realistic RMS rating. An amp sends your speakers the power they need to deliver your music with clarity and impact, whether you're using factory speakers or high-performance components. And low-frequency reproduction requires lots of power, so an amp is an absolute must if you're adding a sub to your system.

JBL GTO-804EZ Reviews

Average Customer Review:

2 Reviews

jbl gto-804 ez

Written by: jjjjj from san diego on December 3, 2012

sweet sound on two sets of 5 -1/4 ks kicker component speakers love the sound ez to adjust amp

Pros: everything the shhhhht

Cons: none so far

Great Sound very solid amp

Written by: Giovanny from Boston, MA on June 10, 2012

Crutchfield Customer Review (What's this?)

Great quality AMP. I have this amp powering 2 sets of Boston acoustic SR60 Component set and the combination sounds amazing ! I do recommend this AMP

Pros: Small form factor. Knob controls. Amazing sound quality

Cons: Signal sense power on does not work as well as expected. With the Signal sense power on if you are operation at a low volum after about 5 minutes the amp shuts off. I recommend running a remote power on cable to this amp.

Hands-on research

What's in the box?

Download owner's manual

  • 4-Channel amplifier
  • Two 25-amp ATO fuses (installed)
  • 4 Speaker wire to RCA adapters
  • Setup CD
  • Warranty information
  • Owner's manual (English/ German/ French/ Spanish/ Dutch/ Italian/ Swedish/ Danish/ Finnish/ Korean/ Japanese/ Chinese/ Russian/ Polish/ Portuguese/ Turkish/ Indonesian)

Product Research



Multi-Channel Design: The JBL GTO-804EZ is a 4-channel amplifier, basically two independent 2-channel amplifiers built into one chassis. Either half can be bridged so it can be used as a 4-channel, 3-channel, or 2-channel amplifier. The amplifier is stable to 2-ohms in stereo, and 4-ohms when bridged.

CEA 2006 Compliant: The power ratings are measured according to the Consumer Electronics Association CEA-2006 standards. These standards allow you to accurately compare the rated power output of all CEA 2006-compliant amplifiers, even different brands. Manufacturers who adhere to the standards can display the CEA 2006 logo on their products and packaging. The power output is measured from 20 Hz to 20 kHz, using a 14.4 volt power supply, and with no more than 1% THD+N:

  • 4-Channel (4-ohm): 80 watts x 4-channels into 4-ohms
  • 4-Channel (2-ohm): 100 watts x 4-channels into 2-ohms (2-ohms minimum)
  • 2-Channel (Bridged): 200 watts x 2-channels into 4-ohms (4-ohms minimum)

Setup Disc: The included setup CD is used to optimize the input gain. A test tone is output from the disc and the Gain LEDs on the amp (green, yellow, red) guide you through adjusting the gain controls.

Note: The instructions in the first version of the manual indicate the radio should be at full volume when playing the setup disc; this is wrong and JBL is in the process of correcting the manual. The volume should actually be as high as possible without distorting the signal; this will be different for every radio, but approximately 3/4 volume is typical.

Auto Turn-on: The GTO-804EZ has a signal sensing automatic turn-on circuit; it will turn on whenever an audio signal is present at any of the RCA inputs. The amplifier will automatically turn off approximately five minutes after the input signal ceases. If you prefer to use the radio's remote lead, the auto turn-on feature can be turned off.

Crossovers: There are independent crossovers for the front and rear channels built-in. Each crossover can be set to high-pass, low-pass, or full range (bypassed). The crossover points are continuously variable from 40 Hz to 220 Hz and adjusted independently. The slope of both crossovers is 12 dB/octave.

Audio Input: If your radio has no line-level outputs, use the included adapters to convert the speaker wires to RCA and plug them into the amplifier's inputs. The input level switch has a Hi2 position, used to present a speaker load to factory radios equipped with a circuit that turns the radio off when an amp is connected.

Line Level Output: The amplifier has a pair of RCA line level outputs to feed a full-range stereo signal to another amplifier. The GTO-804EZ's crossovers have no effect on the line output signal.

Routing Switch: The signal for the front and rear amplifier channels can be supplied from the separate front and rear inputs (two pair of stereo RCAs), or from just the front channel inputs (stereo RCAs). Set the switch to F&R (front and rear) or F (front).

Bass Boost: A bass boost circuit, centered at 45 Hz, can be applied to the rear channels. The boost is variable from zero to +12 dB. JBL recommends only using bass boost when the rear channels are bridged to power a subwoofer.



  • Front channels:
    • Crossover selector: three position switch; high-pass, full range, low-pass
    • Crossover Frequency: rotary knob; continuously variable from 40 Hz to 220 Hz
    • Input Gain: rotary knob (the gain LEDs are above the knob)
  • Rear channels:
    • Crossover selector: three position switch; high-pass, full range, low-pass
    • Crossover Frequency: rotary knob; continuously variable from 40 Hz to 220 Hz
    • Input Gain: rotary knob (the gain LEDs are above the knob)
    • Bass Boost: rotary knob; continuously variable from 0 to +12 dB; boost centered at 45 Hz

Right Side:

  • Input Level: three position switch; Low, Hi1, or Hi2 (used only with factory radios having a circuit that turns the radio off when it sees no speaker load)
  • Routing Switch: F (front)/F&R (front and rear)
  • Gain LEDs: on/off


  • Auto Turn-on: on/off


Left Side:

  • Power and Ground Terminals: set screw terminals; accept up to 4 gauge bare wire
    • Note: JBL recommends the power and ground cables be 8 gauge minimum.
  • Remote Turn-on Terminal: set screw terminal; accepts up to 8 gauge bare wire
  • Speaker terminal: four pair of set screw terminals (for front left, front right, rear left, and rear right); accept up to 8 gauge bare wire
  • Fuses: two ports for 25-amp ATO fuses (fuses are factory installed)

Right Side:

  • Audio Input: four female RCA jacks (front left, front right, rear left, and rear right); compatible with speaker level signals using the included adapters
  • Audio Output: two female RCA jacks (left and right)

Our Product Research Team

At Crutchfield, you'll get detailed, accurate information that's hard to find elsewhere. That's because we have our own in-house Product Research team. They verify what’s in the box, check the owner's manual, and record dimensions, features and specs. We stay on top of new products and technologies to help people make informed choices.