Gain stages, compression and tone stacks made simple

Understaing how gain (overdrive and distortion) works is a lot helpful to control your tone.

I like to think that  also your picking and the pickups are gain stages. It helps understand all the layers and how to get the right tone.

This is a bit of explaination of the "tone is in your finger" thing.

Let's say that anything that affect volume also affect gain stages and then overdrive (distortion) and tone.

Then, how hard you hit the string, the pickup power and its volume control, any gain stage that come after and you may know and control, or not.

First of all, lets get rid of one thing: the boost.

A BOOST is a gain stage that rise the volume of the signal without distorting or overdriving it. I know, the final effect may be overdriving of distorting. But that job is done by the next stage. The boost  in fact, help the following step in its work by rising the signal and making the next step overdrive sooner and better.

Since it rises the volume, usually it also compress the tone. What does it mean? Pratically, it shorten the gap between the higher and the lower part of the signal. This may be good or bad, depending on your taste and needs, and also the amount. Too much may be too much. I will come later on this because is relevant part of the gain stages game.

Usually boost have some sort of EQ controls.

TIP: any overdive pedal, with the drive control set at zero can be used as a boost. Obviouls in the same color of the pedal itself. A tube screamer is  frequently used as a mid boost by setting the drive to zero.

So, if you dont mind, i would like, after this explainations, to take all the boost thing out of the equation and concentrating on the overdrive stages and tone stack on its own.

So, why do we stack overdrives? Let's look at pedal stacking for one moment. A lot of pepole se it this way:

"I put 2 overdrives on my pedalboard, a light one (we will give it a value of 3) and a mild one (we will give a value of 5), if i use it together i wil get an higher one (3+5=8!)"

But it not just that. 2 gain stages gives you a slightly different result than a single gain stage of the same "amount". Flavor apart.

Now lets get into it! Let's consider something relitively simple like a plexi. Britsh overdirve in one of is classic incarnation. As we raise its gain from 0 its sweetspot we may notice the first rule of the gain game,

High frequncies distort sooner. 

I think this is the gold rule when you manage gain stages.

Lets think american vs british. american is mid scooped, british is mid pushed. You get something noticeably different when you push the gian in the low overdrive territory. At hte same amount of gain, the american amp will have a lot more high freq overdrive, and a lot less mid freq overdrive, resulting in a arsher, raw overdrive. On the other side the britsh will even mid and high freqs, making the mid frequences overdrives at the same time of the higer ones. This will. result in smoother tone.

So we can see, overdrive flavor has a lot to do with how much we can distort various frequency.

But if you where in the golden era of the plexi you would have want more of it. The first thing to do was rise the volume and use the power section as a second stage with the obvious porblem of the volume.

Then, people like Jose Arredondo stard modding amps to get more gain stages. Modern amps have more gain stages, both valve and solid state. The classic JCM800 has a clipping stage to name one. Just like a fixed overdrive pedal in its gain channel.

Why?