GX Series amplifiers are ideal for professional entertainers who require maximum performance and portability on a limited budget. The hallmarks of the QSC brand - professional audio quality, meticulous engineering, precision manufacturing and long-term reliability - are all intrinsic to GX. Add contemporary styling, multiple input/output options, light weight, and advanced protection circuitry, and the GX Series clearly represents real value - something everyone can use.
GX amplifiers deliver just the right amount of power to the most popular speakers used by entertainers. Typically, loudspeaker manufacturers recommend an amplifier with power output equal to the speaker's Program (Music) Power rating or two times (2 x) the Continuous (RMS) Power rating.
The GX3 is ideal for speakers in the 300 watt (Program) range, while the GX5 provides full performance for 500 watt (Program) speakers. The GX7 outputs 725 watts into an 8 ohm load. Owners of popular 4 ohm loudspeakers (such as dual-woofer, two-way models) will find the 700 watt (4 ohm) power of the GX5 an ideal match while the GX7's 1000 watts will very capably power many of today's popular subwoofers or two typical 8 ohm speakers per channel.
The GX3 uses the latest evolution of the QSC Grounded Collector output system, for optimum cooling of the critical power transistors. A true Class B biasing system combines maximum thermal efficiency with excellent audio performance.
The GX5 uses a Class H system, based on key elements of the PL Series, (PLX, PL3, CX, DCA) almost doubling power in the same size and weight. QSC design expertise allows the output devices to shift from low-power to high-power rails in less than a millionth of a second, ensuring that the output power is always right where it needs to be without excess loss.
Both amplifiers use premium toroidal power transformers for reliable "mid-weight" performance. A variable-speed fan moves air crosswise through the amplifier, drawing cool air in over the power transformer, through the fan, and then over the heat sink. This keeps the transformer cool and allows a full size heat sink to fit in a down-sized chassis.
The GX7 adds the road-proven PowerLight supply to the Class H output section, for more overall output power and additional weight savings. The result is one of the highest power-to-weight ratios in the industry. A low-noise variable-speed fan with rear-to-front airflow keeps amplifiers and racks cool.
As always, GX Series amplifiers are fully protected from the usual hazards of the trade, ensuring stable performance and long life.
GuardRail protection delivers full peak power while preventing detrimental overloads. During excessive clipping, or extreme overheating, GuardRail reduces gain just enough to preserve the integrity of the music, protect the speakers and keep the audience excited, without unprofessional distortion levels or shutdowns.
A subwoofer reduces strain on the full-range speaker, allowing it to play louder, or letting a smaller speaker do the same job. The GX Series supports this mode with a Crossover switch that splits the full-range input entering Ch 1, sending 20 Hz -100 Hz to the sub (Ch 1) and 100 Hz - 20 kHz to the top box (Ch 2). The front panel gain controls balance the sub and top box, while GuardRail optimizes peak power into the sub and top individually, for greater musical impact and dynamic range. GuardRail optimizes peak power into the sub and top individually, for greater musical impact and dynamic range.
- Power levels matched to the most popular speakers used by entertainers
- Optimized for maximum real-world headroom into 4 ohm and 8 ohm speaker systems
- Inputs: XLR, 1/4" TRS and phono input connectors for compatibility with any source
- Outputs: Speakon® combo accepts, 1/4" (TS) plugs or Speakon 2-pole and 4-pole plugs (connects 2 poles only). Binding posts support all other speaker wiring systems
- Minimum depth chassis (10.1"/257 mm) fits in compact, inexpensive effects racks
- Lightweight - GX3 and GX5 less than 26 lbs (12.5 kg). GX7 only 15.5 lbs (7 kg)*
- Detented gain controls for precise setting and matching of sensitivity
- GuardRail™ automatically protects the amplifier and loudspeakers from damage due to temperature rise or overdrive without shutting down the show
- Front panel LEDs monitor Power, Signal and Clipping
- Subwoofer/Satellite crossover built-in
|8 ohms / 1 kHz (both channels driven)
|8 ohms / 1 kHz (single channel driven)
|4 ohms / 1 kHz (both channels driven)
|4 ohms / 1 kHz (single channel driven)
|Distortion (1 dB below rated power, 1 kHz)
||8 ohms: less than 0.02%
4 ohms: less than 0.05%
|Signal to Noise (20 Hz - 20 kHz)
|Voltage Gain (8 ohms)
||2-tier Class H
||2-tier Class H
|Power Requirements (1/8 power, pink noise at 4 ohms, 120V)
||20 Hz - 20 kHz, +0, -1 dB
|Dynamic Headroom (4 ohms)
|Input Impedance (ohms)
||Greater than 20k (balanced)
|Maximum Input Level
||+24 dB (16 Vrms)
|Input Connectors (each channel)
||3-pin XLR and 1/4" TRS, balanced, parallel
|Output Connectors (each channel)
||Speakon®, 1/4", Binding Posts
|Amplifier and Load Protection
||Short circuit, open circuit, thermal, RF protection
Load protected against DC faults
|Front Panel Controls and Indicators
||Gain controls, 21 detents
Red Clip LEDs, proportional, 0.1% THD threshold
Green Signal LEDs, threshold -35 dB
Blue Power LED, AC on
|Rear Panel Controls
||Full Range / Crossover switch
100 Hz, 3rd order LP (sub), 2nd order HP (top)
||Height: 3.5" (89 mm) 2RU
Width: 19" (483 mm)
Depth: 10.1" (257 mm)
||Net: 27 lbs (12.1 kg)
Shipping: 31 lbs (14.1 kg)
|Net: 28 lbs (12.6 kg)
Shipping: 32 lbs (14.6 kg)
Net: 15.5 lbs (7 kg)
Shipping: 20.5 lbs (9.3 kg)
Net: 16.5 lbs (7.5 kg)
Shipping: 21.5 lbs (9.75 kg)
||UL, CE, RoHS/WEEE Compliant
|AC Power Consumption
1 1/8 power represents typical operating conditions
|AC Current and Heating, 120 VAC
|8 + 8 ohms, 1/8 power 1
|8 + 8 ohms, 1/3 power 2
|8 + 8 ohms, full power 3
|4 + 4 ohms, 1/8 power 1
|4 + 4 ohms, 1/3 power 2
|4 + 4 ohms, full power 3
2 1/3 power represents peak program levels
3 Full power is breaker limited to short periods
For 230 V, multiply AC current by 0.5
For 100 V, multiply AC current by 1.25