Boost Effect

Why Boosters and What Next?

After finishing four different DIY boosters, natural question is – what’s the fascination with them? After all, they just boost guitar signal, not much more. Come to think of it, maybe I should’ve asked myself this question before I started building them, but here we are and better late then never.

There are several reasons why I chose to build them first and I’ll go through the reasons here. While not the most exciting pedals, boosters are widely used, very versatile and, lets face it – super simple.

Widely Used and Versatile

Despite its simplicity, booster pedal is widely used. I’d say most of the players have one on their pedalboard. Heck, AC/DC did not even use distortion, Angus used a sort of a booster and cranked the amps up to get the sound.

While they just amplify the guitar signal, boosters are surprisingly versatile. They can be used for louder solos, push amp harder for more saturation/breakup, provide permanent boost for longer effect chain to battle signal loss.

That Pedal Show came up with 10 ways to use boost pedals. Not all usages are very common ? but still, good to know that they are out there.

Simplest Useful Effects

But let’s face it, I chose them because they are the simplest effects I can build.

The four pedals explore four different active components and are supposed to be the simplest useful circuits with those components. The active components are 3 different transistor types (BJT, MOSFET and JFET) and an op-amp.

The simplest one shows that with very few components we get a usable pedal. It is a bit surprising that circuit itself is very simple but that all the rest that makes a pedal adds up.

Other two transistor based pedals, using MOSFET and JFET transistors showed that essentially, circuit topologies are more or less the same. JFET based one got to be a bit more complex due to way higher variability of JFET transistor parameters (and I also got a bit carried away).

Op-amp based effect was more complex than the others. Transistor based effects are slightly less complex than op-amp based, but op-amp based booster has a benefit of getting more reproducible result (and nearly any op-amp can be used with similar results).

All different designs have some pros and cons, but ultimately, they are super simple and very similar circuits are used as building blocks in other pedals.

Great Building Blocks

All of the four pedals have very basic control – essentially just a single knob controlling gain or volume. They can be very easily made even better by adding tone control for example.

With handful of passive components for example I can get tone control similar to Big muff or get a classical Marshall or Fender control stack by literally adding these tone stacks after the booster circuit. (Useful tool showing the response of some of these circuits is Tone Stack Calculator). All off a sudden I can model my sound the way I want it.

Or, with some clipping diodes, I get distortion. In fact, MXR Micro Amp is a redesign of MXR Distortion+ with removed clipping diodes (and less gain). Likewise, overdrive or even fuzz (with a bit more effort) can be made with just a handful of additional components.

Actually, nearly all (if not all) pedals I can think of contain at least one amplification stage. And, it is more likely than not that these stages look like one used in the four boosters I made.

So the next steps for me would be to explore adding some extra tone controls and then move on to some distortion. Yeah, that’s what I’ll be doing.

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