Keeley Electronics Compressor Pro

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Keeley Electronics Compressor Pro



On board the Compressor Pro are controls for Threshold, Ratio, Attack, Release and Gain. On top of that we have a Knee Hard/Soft switch and an Auto Mode On/
Off switch. While most guitarists will be familiar with the majority of these controls, this is in no way your average stompbox compressor. The Threshold and Ratio controls are the two fundamental pieces. The Threshold Control works to notify you when the signal is being compressed (red light) and, conversely, when it is passing through unchanged (green light). The Ratio control on the other hand establishes the amount of compression that is being used. With the Threshold Indicator and the LED Compression Meter you have a much a greater understanding of the compression that is being applied. Responsible for then bringing the volume back up to a desirable level is the Gain control, which also doubles as a boost. This three-prong attack alone delivers studio-grade quality. But wait, there’s more.


The Attack knob controls how long it 
takes for the compression to kick in once
 it has passed the Threshold. While the Release knob lets you decide how long the compressor will stay on after the signal
 has dropped below the threshold. Both 
are useful controls, offering the ability to produce resonant sustain and, alternatively, decidedly impactful limiting. However the Auto On/Off switch also allows you to automate these two controls, importantly, without sacrificing quality. This nifty
 little function not only makes it easier to get your head around the pedal, but also offers a viable, fuss-free way to use it. With the Auto switched on, the Threshold (-30d), Ratio (just past 4:1) and Gain (slightly past levity) all dialled in, the compression really pops and packs a punch. I’ve got the Knee switch on Hard, which helps give the compression that more aggressive and profound edge. This adds another dimension to expressive strumming patterns and chord progressions. Flick the Knee switch to Soft, and suddenly we have a more understated, translucent and almost dreamy tone.


Atmospheric sustain for fingerpicking, a mellow smoothing of chords, or a ‘chicken pickin’ good time – there’s really not much that that the Compressor Pro can’t do. In a stompbox and in this price range you will struggle to find a compressor of greater quality and make. 


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