I have found that turning down the volume knob on the guitar to “clean up” the amp wasn’t really working for me. The amp sounded a bit anaemic when I tried to do it.
In this video (at about 9:20) Dagan Wilkin uses a compressor to keep the volume up when cleaning up. Does anyone else use a compressor like this?
I tried it and thought it worked well.
I’d been using the compressor to give my ODR1 overdrive a bit of a kick for solos. So I’ve 2 uses for it now. You can see my current set up here:
fwiw, have ya considered playing dynamics? This is my typical way to go from clean to kinda dirty in my case.
The compressor idea looks reasonable to me. A good idea even. I had a compressor in my chain but removed it. Pretty sure it had a vol. control on it. Pretty sure I remember it’d increase vol., if dialed in that way, from pedal not engaged.
As for your video. Thanks. I been thinking about that 10 band mxr eq pedal that was on that board. That video ain’t helping my GAS! 
Yes, a good compressor pedal can be a nice clean boost, and add some sustain for single coils. In some cases they can add unwanted noise, and with humbuckers they are of little use (IMHO).
I’m confused. I’ve looked at an explanation of compressors by Josh Scot, trying to understand what it does (afaik, it has a certain bandwith for the signal to live in. Everyting above or below gets topped of).
But where does “cleaning up” in regards of turning the volume up come in?
Is it because: when you turn up the volume, without compression, you get distortion?
And with compression, you don’t? (thinking of the bandwith here).
And how can it give a volume boost, since it’s narrowing the frequencies?
That’s not really correct.
That depends on the type of compressor. Certain models of compressor have specific frequency-dependent characteristics. But that’s not how compressors work in general.
There are many compressors which are not specifically frequency dependent, and work across the whole audible frequency range.
A compressor can be thought of a bit like an automatic gain control. If the signal gets to loud, the compressor turns it down a bit. If it gets too quiet, it turns it up.
So, when you pluck a note, normally it starts loud and tails off, going quiet fairly quickly. A compressor will keep turning the volume up to keep the note sounding loud.
That is, until it reaches a point where it cannot sensibly turn it up any longer and, at that point the note is allowed to die out. (This level is called the “threshold” on most compressors).
A (often desirable) side-effect of this is that notes sustain longer.
That is the basics of how compressors work and, if you think about it, if the notes stay loud for longer, that makes the average level louder. It is the peak levels that cause the amp to go into overdrive. So, by making notes on average louder without making the peaks louder, you can get more volume without pushing the amp into overdrive.
The full description of this is “dynamic range compression” because you are reducing (or “compressing”) the difference between loud and quiet sounds (which is known as “dynamic range” or just “dynamics”). You are making all the notes much more even in volume.
The downside of this is that it reduces dynamics. What do I mean by this? I mean that if you want to pick some notes quiet and some notes loud, too much compression will stop you doing this.
So some people like to use picking dynamics (picking harder or softer) to control whether the amp goes into overdrive or not:
This is a powerful technique when done right, but it requires a degree of picking control, and it also requires the amp (and any pedals in front of it) to be set up just right. The classic setup here is the “edge of breakup” tone.
Depending on your setup, it can limit how “dirty” you can get.
There are cases where picking dynamics works best, and others where turning down the guitar volume control works best. The compressor is just a tool which helps in the latter case.
Cheers,
Keith
Regarding the frequency ranges:
There are certain implementations of compressor which are frequency dependent. Often this is done by including an equaliser (EQ) or tone control as part of the circuit. This is particularly the case for guitar pedals.
The idea here is that you are only boosting the average level in certain frequency ranges. The idea is here that you want to boost the average level of the guitar at frequencies where it sounds best, especially in the context of other instruments playing.
Typically you may want to reduce bass frequencies (where the drummer and bass player are) and reduce very high frequencies which often sound harsh.
So the mid-range (typically) is sustained whilst the bass and treble frequencies are allowed to die out naturally. And, yes, this will change the tone of sustained notes (which is often desired).
This is really about EQ than compression. It’s just that may compressor pedals include an EQ as a convenience capability. You could achieve the same thing with a full-bandwidth compressor with an EQ pedal in front, but that would be an additional pedal and wiring.
Some pedals (like the Boss CP-1X) actually have multiple compression circuits for different frequencies (known as “multi-band compressors”) which allows more control.
Cheers,
Keith
Thank you Keith for this good explanation, I am going to try out my Compugilist Fender again, 
which I have not used for many years because of your story (only for distortion)
Greetings
@Majik indeed, thank you for your explanation.
You don’t happen to have some albums where this is clearly audible?
That way, i can hear the theory in action. 
Every album you have ever listened to!
The problem is that, even if the guitar player isn’t using a compressor pedal, the mix engineer will be applying compression in the mix. The application of compression is a standard part of mixing (and has been since the 1960s).
Also, any time you overdrive a guitar amp, you are applying compression, as this is the natural side-effect of overdrive (which is why overdriven guitars sustain longer).
So, there aren’t going to be many cases of commercially produced music where the effect of a compressor pedal (specifically) is going to be very obvious.
Probably the best I can think of is funk guitar strumming, where it’s very common to employ a lot of compression. Anything from Nile Rogers, for example.
Cheers,
Keith
One question from me, if I may. 
I know the compressor goes in the beginning of the chain. Why is this so? Wouldn’t distorsion come later from boost pedal → overdrive pedal → distortion pedal → amplifier where in each of these you have gain control? I understand that the main signal comes from guitar pickups, but wouldn’t it be optimal to place compressor in your chain just after amplifier, when you already finished dialing your total gain?
As a second question, is there a right way or formula where in the above chain we change gain first, i.e amp before pedals, etc?
Commonly, yes, although you could put it in other places.
As I suggested, the main function of a compressor is to “even out” the guitar level by restricting its dynamic range. Although this increases the overall average volume level, that’s not the same as “gain” which is generally about boosting the instantaneous signal level.
Whereas a boost pedal specifically is designed to increase instantaneous signal level which is commonly used to push the amp into overdrive.
A side note on this: some compressor pedals do have a gain control, this is more properly known as “make up gain” because it’s there to “make up” any loss of level caused by the compression taming the peaks. It’s not usually supposed to be used as a general gain control, although some people will use it in this way.
I’m going to ignore this use and assume that, where present, this is used as a make up gain control, rather than a boost function.
There’s no reason you couldn’t (other than, if you are relying on amp overdrive, you would need an FX loop to do this). And there are cases where people will do this. One case I have heard of is where the compressor is put after a particularly spiky fuzz to control it a bit.
But, generally, compressors are used before overdrive/distortion specifically because you are using it to control the levels going into the overdrive/distortion to prevent the odd dynamic pushing the signal into overdrive.
Remember, the topic of this thread was about using a compressor to create more volume for clean tones.
If you put the compressor after the overdrive, then playing hard would still put the amp into overdrive and the compressor would just even out that overdriven tone a bit.
Not particularly. It really depends what sound you are trying to achieve, and what equipment you have.
Note that overdrive and distortion pedals are designed to create their own overdrive/distortion, independently of the amp. This is, strictly speaking, not the same as “gain”, although guitarists often mislabel it as such.
“Gain” really is just boosting the signal level. It doesn’t imply overdrive or distortion. It just means the signal level is increased. Overdrive is the effect you get when a signal is “hot” enough that it causes the circuits to overload. So “gain” is used to help produce overdrive, and an overdrive pedal will use internal gain circuits to create overdrive.
But an overdrive or distortion pedal is not, itself, a “gain” pedal (in the strict sense of the term). In fact, if it has a level control, it’s entirely possible that the level coming out of an overdrive pedal is lower than the signal level going in (although that would be unusual).
As I said before, a compression pedal isn’t really a gain pedal. It, typically, is used to increase the average level, but the instantaneous peak levels are, if anything, reduced. Putting a compressor before an overdrive will normally cause the softer notes to be more overdriven, whilst reducing the amount of overdrive on the louder notes. Overall, you will get more sustain.
A “clean boost” pedal is really a pure gain pedal.
So, if you are looking at gain, the question becomes: what are you trying to do?
Typically, you are looking to use gain (e.g. with a boost pedal) to push a circuit (either an overdrive pedal or an amp input stages) into overdrive. Note this is more common with amp overdrive because most overdrive pedals include their own boost circuit before the overdrive circuit, so you don’t always need a separate boost pedal.
In such a setup, you set the amp up so that normal playing is clean, and then set the level of the boost circuit to push the amp into overdrive when it’s engaged. You can then switch between clean and overdrive by turning on the boost pedal.
Equally you can also use this to go from “moderately overdriven” to “very overdriven”.
Putting an overdrive pedal in front of an overdriven amp isn’t really about using “gain” to drive the amp. It’s about “stacking” overdrives. Here, the overdrive pedal produces an overdriven sound which is harmonically rich with lots of overtones, and the amp then applies its own overdrive to that signal. This can produce a thicker, more harmonically rich sound.
I will mention that whilst “overdrive” normally refers to a natural form of distortion caused by overloading circuits, what we call “distortion” in pedals is an unnatural form, created by artificially degrading the signal using components to hack bits of the signal off. Overdrive is often characterised as “soft clipping” with distortion providing “hard clipping”.
A key practical difference is overdrive is more sensitive to the input level. Distortion is generally not as sensitive to input signal level.
Putting a boost pedal in front of an overdrive or distortion pedal will change the characteristic of the tone by making it more “saturated”. You can also put a boost pedal after an overdrive or distortion if you just want to boost the signal level without changing the tonal characteristics.
Finally, putting a compressor after a heavy overdrive or distortion makes less sense because overdrive and distortion already compress the signal. There may be cases where it works though.
There are conventions to all this, but there are no rules!
Cheers,
Keith
Thank you so much for taking time, I really appreciate it. There is a lot for me to learn.
Kind of. I think it’s to Keith’s @Majik point though about how the amp is set up. I was finding myself spending too long trying to set the amp up for that edge of break up point. So for now I’m getting my overdrive and distortion from effects pedals, with the amps set relatively clean.
@Majik - great stuff Keith on theory and practical use of compressors.