Why Every Guitarist Needs a Compressor Pedal
What is compression?
Not to be confused with the audio data compression, we're talking about the so-called dynamic range compression. Without getting too geeky about it, dynamic compression amplifies quiet parts of your playing (or singing) and lowers down the volume of louder parts. Although the resulting tone has less dynamic range, it gets "thicker" and seems more present. The first use of compression was back in the '30s and the '40s for controlling the voices of speakers in talk shows on television and radio. But knowing how demanding rock musicians are in their search of better tone, compression eventually found its way into the guitar world in form of rack units, pedals, digital effects, and plugins for digital audio workstations (Cubase, Logic, ProTools, etc.).
There are some parameters that give you control over the different aspects of the effect, although some pedals have fewer knobs on them for easier use. There are volume, the threshold for determining at which volume the compression starts, the ratio which determines how much compression will be applied over the threshold, attack, and release. Some compressors also have a tone knob or even a 3-band EQ on them for some additional sound shaping.
Sustain is also a kind of a "side effect" of compression since any amplification of a fading signal will cause it to last longer. Some compression pedals or rack-mounted units have a sustain control knob.
When to use it?
Not that you are somewhat familiar with compression, now you need to know when to apply it in your own music. The effect has its use for both clean and distorted tones. At the same time, it helps in rhythm and solo situations, depending on what you're aiming for.
Playing rhythm guitar, adding some compression to your signal will give you more control and you won't stand out too much in the mix, giving an overall balance with lead instruments. This is why compression is often essential for bass guitars, especially if there's some slapping involved. At the same time, some solo sections can be boosted with a compressor and help you stand out in the mix while giving more even tones, which is sometimes required in certain lead sections.
You'll often hear compression with clean funky guitars, making that recognizable tone played with single-coil pickups. Another example where compression could be applied is with distorted metal tones, although distortion in itself does some compression so you need to find a perfect balance depending on the type of amp and a distortion pedal you have.
Where does it go in the signal chain?
Knowing that it's a dynamic effect, compressor pedals should go after filters, wah pedals, and EQ pedals, and before distortion and overdrive. But since there are no written rules on how you're supposed to arrange your pedals, you are free to experiment and find a combination that suits you the most. The one described here will just give the clearest tone without any unnecessary noise.
Most of the compressors are pretty compact, either in the classic pedal-sized format or even as those mini-sized pedals. So there are usually no problems in fitting a compressor on your pedalboard. If you do have any issues, get rid of that modulation effect that you rarely use.
Famous compressor pedals
Asking any of the countless guitar pros today, the compressor is one of the most important things you need to have in your rig. Knowing this, you might want to try out some compressor pedals yourself and see if it will work well with your playing. Out of all the pedals that you can find on the market these days, there are a few compressor pedals that earned a good reputation among guitarists.
Boss has some great products like the CS-3 and the more advanced version like the CP-1X. Some other companies are also pretty popular with compressor pedal users, like TC Electronic and their Hyper Gravity, which is also a pretty simple one. MRX and their M102 and M132 are also pretty simple, yet they do the job well.
There are also some more complex pedals like the Wampler Ego that has five parameters to control. There's also a pedal like Origin Effects Cali76 Compact Deluxe that features six knobs, giving more control over the player's tone.
Either way, whichever you decide to get, it will most definitely help you create a better tone. At the same time, they're not as fun and as exciting compared to some other effects so some might be discouraged to get one, especially because the compressor requires some getting used to.