Keeley GC2 Compressor/Limiting Amplifier Pedal

As a pedal addict looking for a high-quality, professional-sounding compressor unit that can control and tame your sound, this is the pedal for you.

Great components for Studio-Quality Compression:

The GC-2 is built with only the best components, providing you with studio-quality compression and limiting. The GC-2 is based around the THAT Corp. 4320 circuit, with voltage-controlled amplifiers and high-performance op-amps. This gives you high-fidelity compression which you can precisely control for the perfect sound in your head. There are many compressors on the market that squash your sound too much and dampen your tone. The GC-2 can achieve this but is also very transparent if you want it to be, with a low noise floor that reduces hum from your rig.

Perfect for many applications:

The GC-2 can handle huge signals and has over 20KHz of bandwidth. With a full frequency range, you can use this pedal as the perfect studio tool and run almost anything through it - Guitar, bass, keyboards/synths, drum machines, and a lot more!

Simple but necessary Controls:

Compressors can sometimes have many complicated controls that are difficult to understand, but Keeley have nailed this down to 3 essentials for you.

Threshold - You can use the threshold to search for peaks in your sound, with an ergonomic indicator light letting you know what playing to limit – simple! This can reduce and restrict harsh distortion from your amp, making it less likely for you to damage your speakers (and your ears!).

Compression (Ratio) – This control lets you decide the amount of “squash” when your signal exceeds the threshold. Crank this for a hard-knee limiter-style sound, perfect if you play funk and R ’n’ B.

Gain – You can affect the volume of your signal with the Gain control. If you turn down the Compression knob really low with the Gain high, you can add a musical and crisp boost to your sound.

The Keeley Compressor GC-2 Limiting Amplifier. The same great professional compression/limiting technology available in our Bassist Limiting Amplifier, for musicians and compressor fans of all kinds!

Precision Compression

The Keeley Compressor GC-2 Limiting Amplifier provides true high-fidelity compression and limiting.

The Keeley Compressor GC-2 Limiting Amplifier is built around the exotic and extremely high-fidelity THAT Corp. 4320.  Think of it as very musical studio-grade compressor in stomp box format!  It uses high performance Voltage Controlled Amplifiers, on board true-RMS detector, and ultra-high performance op-amps to bring you the very best quality. This type of compressor gives you precise control and very musical results. This along with a full frequency range means that the GC-2 Limiting Amplifier compressor is well suited for guitar, keyboards, drum machines and, really, anything you can throw at it. The Keeley GC-2 Limiting Amplifier is both musical and transparent.  Where our older compressors were based on the CA3080 or the LM13700 and are perfect for that “Compressor Effect” and are still in use by tens of thousands of players, the new Keeley GC-2 is a different style compressor, aimed at being the ultimate in low noise and transparency.  Not only can it handle astonishingly large signals, but it has an incredible bandwidth of over 20 KHz.  No detail in your guitar’s tone will be lost.  The Keeley GC-2 will be a sound investment in your tone–you now have genuine rack-mount quality at your feet.

Compression and Threshold

When musicians use the new Keeley Compressor GC-2, they will be greeted with a sound that is more easily amplified and heard.  Using the effect as a limiting amplifier saves your speakers from clipping and distortion.  Set the Threshold to look for peaks in your signal and limit distortion from your amplifier or damage to your speakers.  Simply watch the Threshold Indicator light to see what type of playing you want to limit; it’s that easy!  Next, set the Compression Ratio Control to determine how much squash you want when the signal is above Threshold.  Set Compression all of the way down (1:1) for no compression and use the Gain control as a boost.  Set Compression all of the way up for an above-Threshold, hard-knee limiter.

Attack and Release

There is a certain figure that just sounds good as far as compression goes, and that’s 125 dB/second.  With feed-forward compressors that use this type of true-RMS detector you use a single time-constant parameter.  The timing capacitor gives you attack and release times that are adaptive to your playing level or the signal input to the compressor.  Bottom line: Attack and Release times vary on program content.  Attack times are, generally speaking, about 100 times faster than release times.

Attack Time: typically 15ms for 10dB, 5ms for 20dB, 3ms for 30dB

Release Time: typically 8ms for 1dB, 40ms for 5dB, 80ms for 10dB, 160ms for 20dB, 240ms for 30dB

Tone Control and Blend

None – You don’t need a tone control or a blend control on a compressor.  In fact, in our opinion it’s not a good idea.  If you want a blend control, you are undoing your compressor.  Instead, set the Threshold high and only let peaks be processed and then set the Compression Ratio to 2:1 or 4:1.  Much smarter.  So, tone control?  None here. It has tone for days, and there is no need to add treble response back into the mix.  Its ultra slick, feed-forward compression design helps maintain high-end treble response like no other.  Lastly, Tone Controls and Blend Controls only add noise in a compressor.  Why add noise to a compressor circuit?

Specs:

Voltage Input: 9.6V

Current Draw: 15mA

Input Impedance 1 Meg ohm

Output Impedance: 100 ohm

Output Voltage Gain: +30dB Boost

Bandwidth > 20kHz

Total Harmonic Distortion: 0.1%

Noise: -95dBV

Threshold Indicator: Dual LED