QSC GX5 Power Amplifier
The QSC GX5 amplifier is the middle child in the much-acclaimed QSC GX line. To 8 ohm speakers, it delivers 500 watts of output in a 2-channel speaker system, and 600 watts in a single channel output. To 4 ohm speakers, it delivers 700 watts of output when driving a 2-channel setup, and 850 watts as a single channel output. The QSC GX5 is a true 2-tier Class H amplification system, achieving superior heat gain management and the peerless audio quality that we have come to expect from QSC. At this wattage and size, the QSC GX5 would be best suited to driving the PA in a medium sized club or venue, or for driving multiple onstage monitors.
I/O Designed for Contemporary Applications
The GX Series amplifiers are designed with an I/O intended to be useful for the greatest number of contemporary musicians and DJs. It features a single balanced XLR and 1/4-inch TRS on BOTH channels. It also has RCA phono connectors to hook up with whatever other audio source you may be running through this amp. A 100 Hz LF/HF Crossover switch allows you to toggle to and from Full Range mode.
The GX3 also features a Speakon combo XLR/TRS connector on each channel with 2-pole and 4-pole plugs. There are also positive/negative binding posts here to cover all other speaker wiring configurations.
GuardRail: QSC’s Proprietary Heat and Volume Gain Limiter
Every amplifier in the GX Series makes excellent use of its onboard GuardRail system, which combines Clip Limiting and Thermal Limiting into a single active system. QSC intelligently recognized that most power amps are used at the highest possible output at all times, and that clipping derived from heat gain or speaker overdrive should be taken for granted as a problem facing most users.
Its unique design works by measuring the onset of clipping, showing you the peak level via the Clip LED light. It automatically factors the variables of Load Impedance, AC voltage, and power supply and compensates in kind. This way, a milder triggering of the Clip LED does not necessarily trigger the Clip Limiting. Instead, the GX amps target heavy and prolonged clipping, causing a “slow” limiter to gradually reduce the dynamics until the amount of clipping is deemed reasonable. This design aims to do better than other peak limiters by seeking not to eliminate ALL clipping — but only to intervene as gently as possible on excessive peaks and distortion. This avoids the dramatic and unpleasant “drop out” moments created by other powered speakers that effect substantial gain decreases at the first sign of clipping.
The GX Series also utilizes this feature to compensate for overheating. In such situations, the gain is gradually reduced to prevent the need for thermal muting. Overall, the GX Series does better than other power amps by limiting peak clipping only as much is as absolutely necessary.
The Essence Of Strength and Portability
The QSC GX3 is made of an all-steel case, in a minimum-depth chassis. It will fit in any compact rack mount.
– 2 x balanced XLR and 1/4-inch TRS (one on each channel)
– RCA phono connectors
– Speakon combo XLR/TRS connectors (on each channel)
– 2-pole and 4-pole plugs
– Positive/negative binding posts
– 100 Hz LF/HF Crossover switch
– GuardRail Heat and Peak limiting system
– Clipping monitor LED light
– All-steel chassis
– 8 Ohms / both channels driven: 500 Watts
– 8 Ohms / single channel driven: 600 Watts
– 4 Ohms / both channels driven: 700 Watts
– 4 Ohms / single channel driven: 850 Watts- Signal to Noise (20 Hz – 20 kHz): 100 dB
– Input Sensitivity: 1.2 Vrms
– Voltage Gain (8 Ohms): 34.4 dB
– Output Circuitry: 2-tier Class H
– Power Requirements: 6A
– 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
– 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: 26 lbs (12 kg)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
– 8 Ohms: less than 0.05%
– 4 Ohms: less than 0.1%