I Don't Get Compressors; Help Me Understand

Discussion in 'The Stomp Box' started by Agave_Blue, Feb 7, 2011.

  1. Agave_Blue

    Agave_Blue Friend of Leo's

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    I get the idea that they can help lower the louds and raise the softs.

    I don't get how to use them - what knobs to twist to do what. Same for other similar type filters/boxes with "sustain", "attack" and "release" - like enevelope filters.

    I've read that you can help enhance/increase the Tele "twang" by using a compressor. How? What knobs do you twist to do that?

    I don't get what "attack" and/or "release" does to tone.
     
  2. lefty73

    lefty73 Tele-Afflicted

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    Compression is one of those effects that when used properly, you barely notice it's there. On their own, most compressors don't change tone at all, though some can darken a tone somewhat (the MXR Dyna-Comp is famed for this). But it might be a pleasing "dark", one that helps make an ice-pick Strat or Tele fit more nicely in the overall mix.

    Here's a generic overview of what some knob twisting will do:

    Threshold - Compressors generally only work once the input exceeds a certain level, usually measured in the friendly decibel (dB). This level is called the threshold. The lower the threshold (i.e. -20 dB vs. -5 dB) the more signal gets compression applied to it. If you want your guitar to have a mellower sound that evens out louder strumming and picked single-note lines, set the threshold fairly high. If you want some serious chicken-pickin', set that threshold value as low as you can stand so all the notes are squashed to the same volume level.

    Attack - this is a measure of how quickly the compressor reacts and compresses signal levels that are above the threshold. Vocals typically require fast attack times; instruments tend to fall in the middle of the range of a knob that adjusts attack.

    Release - may also be called "sustain". This controls the amount of "squash" the compressor applies to a signal or volume level that is below the threshold. Generally a longer release makes for less noticeable compression.

    Your ears should tell you when you've overdone it. If it sounds unnatural and the volume seems to "breathe", then the compressor is working a little too hard and you need to tweak the pedal or rack unit.

    Ideally, a compressor should be at the front of a guitar effects chain, typically after the wah and followed by everything else. A compressor properly set up for your guitar and amp combination brings new life to chords where the notes are voiced closely together, especially with distortion or overdrive. Not only does it reduce the "mud" that can occur, especially on a neck pickup, but the overdrive pedal may react in a much more musical way to a more evenly balanced signal.
     
  3. frankg11

    frankg11 Tele-Holic

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    lefty73,

    Thanks for that well written explanation. I have a compressor and know what it's suppose to do just not how to tune it. Time to break it out again and try to use it again.
     
  4. Agave_Blue

    Agave_Blue Friend of Leo's

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    Thank you for the nice write up.

    Lets say you were trying to enhance the "Tele Twang". Generally what would you adjust and to what extent?
     
  5. lefty73

    lefty73 Tele-Afflicted

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    A few years ago I was completely clueless about compressors, so old dogs can learn a few new tricks, I suppose. Glad to help.

    If you're yearnin' for the Brad Paisley, Albert Lee, Chet Atkins, Jerry Reed sound, here's my suggestions. Your mileage will likely vary as I am pretty heavy-handed with my picking, but I think these should be good places to start.

    If using a Keeley, MXR Dyna-Comp, or any two-knob stompbox compressor where the only controls are Level and Sustain, set the Level to match the volume when the pedal is off and start off with the Sustain set to noon. Adjust the Sustain amount to taste. When I had a Dyna-Comp I found 1 o'clock on the Sustain and 3 o'clock on the Level were good enough for me. Warning: the higher the Sustain is dialed up, the more obvious the compression effect will be. At really high settings you'll really hear a "pop" when you strike the string with a pick, less so when you use fingers.

    If using a Boss CS-3 or similar stompbox pedal that has Level, Tone, Attack, and Sustain controls, start with the Level and Tone at noon, and Attack and Sustain at minimum. Set Level and Tone to match the tone and volume when the pedal is off. Try setting the Attack to about 11 o'clock and the Sustain to noon. If you want more "pop", ratchet up the Attack knob, but remember the more Attack you add the more likely "breathing" might occur. Unless you're shooting for a unique "swell" effect you might have to back off the Sustain so the compressor is only working on keeping the volume of the initial pick strikes even, and not adding sustain.

    If you're using something like what I have (the JoeMeek FloorQ) that has controls for Threshold, Ratio, or Slope, etc., try setting the Threshold to about -8 dB, the Ratio/Slope to about 5:1 or 6:1 if you can stand it, with a quick Attack time and a medium Release.
     
  6. lefty73

    lefty73 Tele-Afflicted

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    No problem! They're a very misunderstood effect, which is too bad because having one in your rig and properly set up can really make a subtle, yet dramatic, helpful difference not only for your guitar-to-amp sound (as most compressors don't really affect tone), but for your effected sounds, too.
     
  7. Agave_Blue

    Agave_Blue Friend of Leo's

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    Excellent. Thanks again.

    I'll give those starting settings a try and tweak from there.
     
  8. rokdog49

    rokdog49 Friend of Leo's

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    I agree with Lefty73. I use the Visual Sound Comp to darken my Tele tones thru my DRRI and give some punch to the notes. I use it but with only a little compression and a little gain.
     
  9. ironmike

    ironmike Tele-Meister

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    lefty just gave the best online response I've ever seen on how a compressor works. Somebody oughtta make that sticky or something.
     
  10. roflcopter

    roflcopter TDPRI Member

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    agreed. it ttok me a long time to figure out my behring dc-p (dyna comp) and i just got a cs-3 and have been having a hard time with it as well. thanks for the great direction.
     
  11. guit30

    guit30 Tele-Afflicted

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    I have not used any of my compressors all year, been playing acoustic
     
  12. Agitator

    Agitator Friend of Leo's

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    That's extremely fascinating.
     
  13. Impulse

    Impulse Tele-Meister

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    LOL!
     
  14. david_lewis93

    david_lewis93 Tele-Holic

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    Hummm,,,ok,,,so ,,I should run the super comp in front of the orange phase 90 then to make every thing sound sweet if I am running it through my Marshall MG100 ,or my Blues Jr,,(at this time I am pushing an Ibanez 4-12 with either amp ). ANd while I am here ,can I run the 15 wat Jr. through the 100 input jack??(yes with both amps on)
    Just askin.

    bend em tight and let er scream
     
  15. lefty73

    lefty73 Tele-Afflicted

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    Not sure what this has to do with the topic at-hand, but I'll answer anyway.

    If connect the speaker output of the Blues Junior to the input of the Marshall (or any other amp) you will destroy the Blues Junior, and possibly the other amp. Speaker outputs are for speaker loads only.
     
  16. lefty73

    lefty73 Tele-Afflicted

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    You could also run the Phase 90 before the compressor. I run my Boss flanger before my compressor because it helps to remove the volume boost that occurs whenever I turn on the flanger.
     
  17. czech-one-2

    czech-one-2 Friend of Leo's

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    Well, if you knew guit30 it sure is! He's owned most of them and always posts here about his compressor findings. Frankly, I was wondering where he's been! :lol:

    Oh, I use a Boss CS-2 as a clean boost and to goose my overdrive/distortion or fuzz pedals for that little push over the top.Mostly just to give clean licks a bit of warmth,roundness and volume boost.
     
  18. zombiwoof

    zombiwoof Tele-Afflicted

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    Thanks for the concise explanation of the terms. I do notice that pedal manufacturers seem to use "attack" and "release" interchangeably, for instance the DOD FX80B first labeled the control "attack", then changed it to "release" for a while, and then went back to "attack" on later versions. I've also read on a forum that the attack control on some comps is actually a release control that is mis-named attack. Are there any comp pedals that have both "attack" and "release" controls on them?. I've not seen any myself, and have been a little confused about the difference between the two.

    I also wonder about "threshold", my Bench Press (Ross clone with LED, true bypass, and added "attack" control) has level, attack, and threshold controls. A Dynacomp-type pedal has level (or output) and "sensitivity" controls. It seems to me that "threshold" and "sensitivity" seem to do the same thing on these two pedals, so I'm assuming they are two names for the same function.

    I haven't had any problem figuring out how to set my comps, but didn't completely understand the difference in some of these functions. Your explanations do help, though.

    Al
     
  19. Impulse

    Impulse Tele-Meister

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    Exactly. The DynaComp has a fixed ratio, so you can only change the threshold.
     
  20. david_lewis93

    david_lewis93 Tele-Holic

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    Ok Thanks was just askin bout the amps,,so I had the comp correct the first time then ..Thanks for all the right answers ,,I WONT push the Marshall ,,just the 4/12.and switch the jumper cable back to the way it was.

    bend em tight and let er scream
     
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