I found myself in very weird situation. Today, i simply had nothing to say. But i can’t pass on a colorless writing, as that would mess up my OCD. I did start on one more demanding subject, but i realised i won’t be able to finish it without messing up my schedule. So i just needed to drop that topic (it’ll be featured as part 16) and write something else instead. I needed a subject that would be easier to cover. So why not bring up this age old question about how to categorise the effects that produce distorted tones.
Fuzz versus Overdrive versus Distortion?
Exactly. How do we tell which one is which? How can we be certain that a Tubescreamer is in fact a overdrive effect rather than a distortion? We can’t. It’s more likely all in the marketing speak than in real world electronic designs. Let’s start with the early days of distorted tone. Legend has it that certain guitarist for a group called The Kinks used a razor blade to slash a cheap combo amp’s speaker cone to get that distorted sound for one 60’s hit recording. Later in the sixties we were blessed with a ton of fuzz effects that were designed to mimic that broken speaker cone. The most basic fuzz design was (and still is) called a shunt-series feedback amplifier. The circuit was well known before any fuzz pedal was ever produced. The fact that a guitar’s output is enough to push this circuit to sweet distortion wasn’t exactly mentioned on the text book the circuit was originally from. But there you have it. A very first electronic guitar effect that gives out a distorted tone.
In early seventies other types of pedals started to emerge. Some were called boosters and some were called distortion boosters, but they were still mostly boxes with fuzz sounds coming out of them. Later in the seventies, the dawn for Tubescreamer, DOD OD250, MXR Distortion+, Boss OD-1, DS-1 and ProCo Rat widened the spectrum of distorted tones available. That may not be complete list of units that suit the bill, but it’ll get us going. It must have been in those days when the split happened.
Let’s look at the OD250 and Dist+ first. These two pedals share the circuit topology with each other. Main difference is the type of hard clipping diodes after the gain stage. OD250 uses Si diodes with lower voltage drop and more volume, while Dist+ has Ge diodes with higher voltage drop and less volume. This means that the sound of these is very close to each other. Nevertheless, the former was (and still is) marketed as Overdrive/Preamp and the latter as a Distortion. You guys must now be getting my point?
Boss DS-1 works in same principles as the two, but it has more driving stages. ProCo Rat has similarities too, although its gain control isn’t even close. I’d like to point out that some Rat versions had a text “fuzztones for connoisseur” printed on their circuit boards. So is the classic Rat a Distortion or a Fuzz?
The debate may still be going on which one was the first to take clipping diodes to the feedback loop of non-inverting amplifier and creating softer clipping. Usual answers to this 40 year old debate would be TS808 and OD-1. I have no idea which was the first, so i’m not going to waste my time in speculating about that. There are hundreds and hundreds forum posts about this subject to be found on the interwebs. In case you are interested. These pedals with soft clipping are usually referred as overdrives. Although, there are numerous distortion designs out there with similar clipping diode arrangement.
To sum it up?
A fuzz. This should the easiest one to point out. No clipping diodes and no opamps. Just a bunch of transistors driving the hell out of each other in order to create clipped or distorted signal. But is it that simple? As usual, no. Take a EHX Big Muff Pi for example. This design (and its hundreds of derivatives) is often referred to as a fuzz. Another nice examples would be Anderton’s tube Sound Fuzz and Colorsound Tonebender reissue from the 90’s. I’d call all of those distortions or overdrives rather than fuzzes.
Going forward with the Distortion. This one may be simpler. Hard clipping diodes. But even here, this may not always be the case. There are pedals like ZVex Distortron that is usually considered a distortion, but to my ears it sounds (without going any further on its electronics) a way more like an overdrive. As the earlier example with OD250/Dist+ shows, the design with hard clipping could also be called just about anything.
Overdrive? Now this leaves us with soft clipping and thus, these should be easier to identify. But no. If we take a look at good ol’ Way Huge Red Llama overdrive, we’ll see it’s way closer to Anderton’s Tube Sound Fuzz than any other OD we’ve seen. There are a number of JFET-based overdrives too. These may not have clipping diodes in them at all, but they will still offer full soft clipping sounds.
Is that what you call a sum of the subject?
Well. Maybe not. But it does show us one thing. There isn’t one clear, or even fuzzy logic to when we call a circuit a fuzz, overdrive or a distortion. It’s all in the head of designer at first – then in the heads of the people at the marketing department and after that – in our heads.
Sure it would be easy for me to think that these pedals are fuzzes, these pedals are overdrives and these pedals are distortions. But that won’t do. We can’t define something that’s completely undefinable. And since there is not a way to define which is which, we all may face the situation where our newly bought a) fuzz sounds like a distortion, b) fuzz sounds like an overdrive, c) overdrive sounds like a fuzz, d) overdrive sounds like a distortion, e) distortion sounds like a fuzz, or f) distortion sounds like an overdrive.
I’m going to leave you with one summing thought – there is no way to define or categorise which is which, from electronic point of view. It’s all in the marketing and in our heads.
This does easily apply to all the other pedal genres as well.