Item #: QSC GX3 LIST

QSC GX3 425 Watt Two Channel Stereo Power Amplifier

Shop QSC GX3 425 Watt Two Channel Stereo Power Amplifier from AMS with 0% Interest Payment Plans and Free Shipping.

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MSRP: $439.99
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Product Description

The QSC GX3 Stereo Power Amplifier is 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.

Purchase a GX Series Amplifier from AMS and Recieve QSC's
QSC 6 Year Extended Warranty
after registering your product at

QSC GX3 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.

See all items from QSC
Helpful Info about the Manufacturer
Phone:  800-772-2834 Warranty:  3 Years; 1 Year on TouchMix; CP Series warranty is 1 year +2 upon registration; B-Stock is 1 (one) Year only!

Product Specifications

Product Specifications

QSC GX3 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)

Customer Reviews

Review: Sound Gremlin Submitted: 7/6/2015

Product Rating5 out of 5 stars.

verified buyer


worth the cost.
Product Rating

Product Review

Very good amp. Great controls, easy to balance the sound output. The multiple output and input types makes it easy to connect into my system. I would buy it again.

Review: ronedee Submitted: 6/14/2013

Product Rating5 out of 5 stars.

verified buyer


What a deal!

Your general opinion of this product.

You just can't beat this deal! Quality, Performance & Price.

Built like a rock. The amp has performed well and seems to be dependable so far.

It's your basic setup, as any slave amp would be. The manual is basically useless but that's not a problem.

The GX 3 has multiple input's, and it is suggested that the RCA ins be used alone with no other signal. The loZ & hiZ may be used simultaneously. The amp needs a strong signal to push it. I have been pushing to "clip" occasionally w/ no adverse effects.

The sound is pretty good! I'm using the GX3 to power my Roland guitar synth. I'm also using a custom 212 stereo cab w/ 2 Eminence 200 watt speakers. The sound is accurate and warm. I haven't encountered any distortion. Although I am a little under-powered. I should've gotten the GX5, but I'm happy for the moment. The amp is fine for small rooms (under 200 people) and for all sorts of utility use.

Review: Jack from Stow, OH Submitted: 7/18/2011

Product Rating4 out of 5 stars.


No Regrets; Great Purchase

Appears very well-made and sturdy! I've only used it a couple of times, although I have previous experience with these amps, and hasn't failed me yet.

I spent several hours looking at amps, and there were many 'pluses' to this. But, the one that stuck out the most was this amp getting 300W @ 8ohms. Many other amps w/similar power is considerably less. Although it has some weight, it's not all that bulky & is a convenient fit. I also like the Speakon-1/4" output---gives more options.

It can't get any easier than plugging it, plugging in your speaker cords, your input and turning it on.

Sounds great (although I have not been able to compare it to other systems).

Review: Dennis L. from Thomaston, CT USA Submitted: 7/5/2011

Product Rating4 out of 5 stars.


QSC GX3: One Great Amp

It's solid-built. Not heavy, but not too light to seem cheap. I like the option for rear rack ears for extra support.

I love the built in crossover to separate the highs from the subs. If I was to add one feature it would be a switch to bridge the two amps together instead of a patch cable.

Just plug in power and signal and GO! Nothing too complicated to learn. If you know the basics of an amplifier, it shouldn't take long at all to use this. The manual is very user-friendly. It's written so that beginners can understand it.

Clean, crisp and clear. I use this with Bose 802's and it doesn't color this sound which is always a plus.

Review: DJ Decybals from lansdale, PA, Submitted: 7/20/2010

Product Rating4 out of 5 stars.


great solid amp

wish it was 10 lbs lighter

simple amp, plug and play

good clean sound

Review: Jose Rivas from Amarillo tx Submitted: 12/29/2009

Product Rating4 out of 5 stars.


cant go wrong with this one

very well made and its very dependable, keeps itself cool for long periods of time

small, and worth every penny

no need for directions, this was my first amp and it rocks

may not seem like alot of power, but it will push what you have

Review: The DJ VA from Pick a City, and i've Been there, Submitted: 6/6/2009

Product Rating4 out of 5 stars.


Best Value Period!!!

Quality is so Great! Very sturdy feel And Solid Connections on the back! And this thing is small and LIGHT! Impossible to believe that this much sound comes out of something so small!

The Internal Crosover is Beastly! It is very Accurate and Since it is Built in, it makes setting up an ease. Although, it is only good for pusing a single sub, so you would need 2 if running two subs

Very Easy, Plug and play. And with RCA inputs it adds to the ease of use. The Speakon connections are closer than i want. when using both outputs disconnecting them becomes a little work, especially when reaching around an amp rack

It sounds perfect in full range mode, in crossover mode bring the earplugs, because the highs SCREAM. Easy fix from your mixing board, but be warned

Review: Selecta T from California Submitted: 10/22/2008

Product Rating4 out of 5 stars.


Great Amp Great Price

This amp is solid I can tell it will hold up for years

The amp will connect to any wire,cable,or plug you have

This amp is well thought out It hooked right up I did not really need to look at the owners manual

The sound stays clear at high levels I dj REGGAE MUSIC so I need a amp to drive big bass this one does it


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