QSC GX3 Power Amplifier (300 Watts)

GX Series amplifiers are ideal for professional entertainers who require maximum performance and portability on a limited budget. QSC designers, headed by Pat Quilter, have optimized output and appearance while reducing raw material cost and weight. It's all here – dramatic styling, easy hookup and adjustments, excellent audio quality and QSC reliability.

GX amplifiers deliver just the right amount of power to the most popular speakers used by entertainers. Most 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. This model supplies the maximum possible power to 4 ohm and 8 ohm loads. Owners of popular 4 ohm loudspeakers (dual-woofer, two-way models and many subwoofers) will find the 700 watt (4 ohm) power of the GX5 an ideal match.

Features

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-inch TRS and phono input connectors for compatibility with any source

Outputs: Speakon combo accepts, 1/4-inch (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 inches/257 mm)

Fits in compact, inexpensive effects racks Lightweight – less than 26 lbs (12.5 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-inGX Entertainer

GX amplifiers deliver just the right amount of power to the most popular speakers used by entertainers. Most 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. The GX3 supplies maximum possible power to 4 ohm and 8 ohm loads.

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. 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.

The amplifier uses 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. As always, the 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.

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.

Technical Info

Specifications

Stereo Mode:
- 8 Ohms / both channels driven: 300 Watts
- 8 Ohms / single channel driven: 350 Watts
- 4 Ohms / both channels driven: 425 Watts
- 4 Ohms / single channel driven: 500 Watts
- 2 Ohms / both channels driven: 200 Watts

Distortion:
- 8 Ohms: less than 0.05%
- 4 Ohms: less than 0.1%

Signal to Noise (20 Hz - 20 kHz): 100 dB

Input Sensitivity: 1.2 Vrms

Voltage Gain (8 Ohms): 32.2 dB

Output Circuitry: Class B

Power Requirements: 6.3A

Frequency Response: 20 Hz - 20 kHz, +0, 1 dB

Dynamic Headroom (4 Ohms): 2 dB

Damping Factor: 100

Input Impedance: Greater than 20k (balanced)

Maximum Input Level: +24 dB (16 Vrms)

Input Connectors (each channel): 3-pin XLR and 1/4-inch TRS, balanced, parallel Phono, unbalanced

Output Connectors (each channel): Speakon, 1/4-inch, 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

Dimensions (H x W x D): 3.5 x 19 x 10.1 inches (89 mm x 483 mm x 257 mm)

Weight: 25 lbs (11.5 kg)

When you need big power at an affordable price, look no further than QSC! Their newest GX-series amps have the features and performance to get you through the gig with no worries. Specially optimized for the most common loudspeaker configurations, they deliver efficient power, high headroom, and more bang for your buck! QSC's new Guard Rail protects your rig from overdrive and thermal damage without cutting out, so the show goes on. An onboard crossover lets you power standard front of house mains, or split to a subwoofer with the proper frequency distribution. Add reliable QSC power to your rig—for less! 300-watt amp optimized for 4- and 8-ohm loads. XLR, 1/4" TRS, and phono inputs, combo Speakon-1/4" TS and binding-post outs. Guard Rail offers thermal/overdrive protection without killing power. Onboard subwoofer crossover.