The JBL® GTO-504EZ four-channel amplifier provides unmatched ease of installation, configuration and calibration for clean, powerful sound. It connects to OEM or aftermarket systems without complicated adapters or setup routines. Use line-level (RCA) signals or speaker-level signals with RCA-to-bare-wire adapters – everything you’ll need is included in the box.
640 watts (max) delivered to four channels of power
The GTO-504EZ four-channel model features 4x50 watts RMS (640 watts max). It has selectable high-pass/low-pass active crossovers and bridgeable channel pairs for total flexibility. Use this amplifier to upgrade from four channels of built-in head-unit power in an aftermarket system, as a building block in a growing system design or, by bridging both channel pairs, as a more powerful amplifier for premium component speakers.
Easy setup and adjustment of input gain
The GTO-504EZ amplifier includes an input-level switch, a setup CD with test signals and LED indicators to tell you when the setting is correct. Simply set the switch, turn the input-level knob and watch for the green light that indicates that the setup is perfect. That’s all there is to it. There’s a reason why the amplifier’s model number contains EZ. This feature significantly reduces installation time and delivers excellent results.
Wired or auto-sensing remote turn-on
JBL engineers have configured the JBL GTO-504EZ amplifier to turn on with a wired input (as in aftermarket systems) or with an auto-sensing circuit that activates whenever the amp detects an audio signal. The auto-sensing feature is helpful when you’re upgrading OEM audio systems that don’t include a remote trigger wire. It’s easily defeated by a switch when you’re using a wired remote turn-on input.
Input signal up to 15 volts (line-level or speaker-level)
The GTO-504EZ amplifier accepts a wide range of inputs up to 15 volts with line-level or speaker-level signals. Using RCA-to-bare-wire adapters included with the amplifier, you can connect to virtually any OEM or aftermarket audio system. The end result is an amplifier that works with the widest range of cars on the road.
Built-in, variable active crossovers
Active 12-decibel/octave low-pass crossovers offer variable filter points between 40Hz and 280Hz. You can select high-pass (HP) filtering, low-pass (LP) filtering or OFF. Importantly, all filter points on the adjustment dial match the silkscreened frequency points on the amplifier chassis – a feature that not all amps provide.
Built-in, variable bass boost
The GTO-504EZ provides a range of bass boost from 0 decibels to +12 decibels, centred at 45Hz. This is a useful feature for restoring some bass that may be limited by the low-frequency response of certain speakers in the system – or to enhance a particular range of bass that the speakers already produce well.
Bridgeable channel pairs
Pairs of the GTO-504EZ system amplifier’s main channels can be bridged into a single, more powerful channel. This setup is useful for flexible audio system designs in a growing system or for full-range speakers in a system that needs more power.
Automatic thermal and low-impedance protection
Amplifier protection is just like insurance; you hope you’ll never need it, but it’s sure nice to have when you do. Thermal protection keeps the GTO-504EZ system amplifier from overworking itself to the point of premature failure. Low-impedance protection keeps the amplifier safe from any speaker or wiring failures that result in short circuits.
