Features • Power levels matched to the most popular speakers used by entertainers • Optimized for maximum real-world headroom into 4Ω and 8Ω 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 * 230V 16.5 lbs (7.5 kg) 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 1000 watts will very capably power many of today’s popular subwoofers or two typical 8 ohm speakers per channel. Technical Notes 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™ 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. Subwoofer/Satellite Crossover 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. Choose the right GX amp for your speakers Model GX3 For 8Ω speakers: 250 W – 350 W (program)a GX5 For 8Ω speakers: 400 W – 600 W (program)b GX7 For 8Ω speakers: 650 W – 800 W (program)c GX Series Professional Power Amplifiers GX3 | GX5 | GX7 a) For 4Ω speakers: 350 W – 500 W (program) b) For 4Ω speakers: 550 W – 900 W (program) c) For 4Ω speakers: 900 W – 1250 W (program) GX Series Preliminary Specifications qscaudio.com All specifications are subject to change without notice. 1675 MacArthur Boulevard • Costa Mesa, CA 92626 • Ph: 800/854-4079 or 714/957-7100 • Fax: 714/754-6174 GX Spec Sheet 04/05/11 ©2011 QSC Audio Products, LLC. All rights reserved. QSC and the QSC logo are registered trademarks of QSC Audio Products, LLC in the U.S. Patent and Trademark office and other countries. GuardRail is a trademark of QSC Audio Products, LLC. Speakon is a trademark of Neutrik. All other trademarks are the property of their respective owners. US patent pending. Other patents may apply. GX3 GX5 GX7 GX7 (230V Only) Stereo Mode - Watts per channel 8Ω / both channels driven / 1 kHz* 8Ω / single channel driven / 1 kHz* 4Ω / both channels driven / 1 kHz* 4Ω / single channel driven / 1 kHz* 300 W 350 W 425 W 500 W 500 W 600 W 700 W 850 W 725 W 800 W 1000 W 1200 W Distortion (typical) 1 kHz: 1 dB below rated power 8Ω: less than 0.02% / 4Ω: less than 0.05% Signal to Noise (20 Hz – 20 kHz) 100 dB Input Sensitivity 1.2 Vrms Voltage Gain (8Ω) 32.2 dB 34.4 dB 36.1 dB Output Circuitry Class B 2-tier Class H 2-tier Class H Power Requirements (1/8 power, pink noise at 4Ω, 120 V) 6.3 A 6 A 10.1 A Frequency Response 20 Hz – 20 kHz, +0, 1 dB Dynamic Headroom (4Ω) 2 dB Damping Factor 100 Input Impedance (Ω) Greater than 20k (balanced) Maximum Input Level +24 dB (16 Vrms) Input Connectors (each channel) 3-pin XLR and 1/4" TRS, balanced, parallel Phono, unbalanced 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) Dimensions (HWD) 3.5" (2 RU) x 19" x 10.1" (89 mm x 483 mm x 257 mm) Weight - Net 27 lb (12.1 kg) 28 lb (12.6 kg) 15.5 lbs (7 kg) 16.5 lbs (7.5 kg) Weight - Shipping 31 lb (14.1 kg) 32 lb (14.6 kg) 20.5 (9.3 kg) 21.5 (9.75 kg) Agency Approvals UL, CE, RoHS/WEEE compliant * At onset of clipping Inputs XLR, 1/4" TRS and phono input connectors for compatibility with any source Crossover Subwoofer/Satellite crossover built-in Speakon® combo output connector accepts 1/4" or Speakon 2 wire connectors Binding post output for compatibility with any loudspeaker wiring scheme Outputs to Speakers please recycle