Simple shematics for line level distorsion


2011-03-31 8:06 pm

I would like to build for myself an FX box with 5+ distortion types, but for line level signals not for guitar. I will also put a wet/dry signal control.

I also want to add an EQ with simple low - high shelf, a dry/wet and have a transformer output for extra distortion/character and to have galvanic separation.

So I could really use some simple distortion circuits for line level signal, I have a bunch of NE5532, lots of PNP NPN silicon transistors,some J201, 2N700, caps resistors and so on, I would prefer to use what I already have, I am not aiming to emulate something specific, sound quality is not an issue, just want to have some creative distortion FX.
Nobody will design that for you, plus there's no commercial offerings that I know of.

If you want that, fine, it's a motivation to study a little, build and test as many "regular" pedals as possible, draw your own conclusions, and custom design it according to your specs.

Many great pedals and amps have been developed that way, first built for personal use by somebody who was not happy with available products, and then became full fledged commercial stuff.

As an example: Matchless amps were born out of Mark Sampson's frustration at not getting more of his favorite VOX amps, go figure.

As they say, "the rest is history".
Many of the projects in this book are designed to work with line level and/or can be adapted to work with it, including several distortions. Electronic Projects for Musicians (9780825695025): Craig Anderton: Books
At the very least, it is a good book to have, because you will learn much from it if you are a beginner.

The difference between a distortion designed for line level and one designed for low (guitar pickup) level is mostly a matter of gain and input impedance. If you take the time to study the signals you are working with, you should be able to tailor nearly any existing distortion/fuzz circuit to get the results you want with the signal levels you are dealing with.
^^^^ excellent suggestion.
Very good book, I bought it when it was fresh out of the press, some 25 or 30 years ago.
Very good ideas, which can be adapted or combined for even more projects.

Only problem, easy to solve, is that some of the semiconductors he used are obsolete, and worse, *not* pin equivalent for modern ones, so many of his PCB designs won't fit ... but anyway his hand applied tape designs ara also obsolete, you should redraw anyway with modern, free software, like what's used around here, so no big deal.

I still cherish my stained, solder burnt original copy.


2009-06-24 10:49 pm
One place to get ideas would be the schematic for the DSP board used in the Vypyrs (you can find it over in Peavey's forums)---the distortion loop is analogue and line level (though it does have one +30V control point; Peavey uses a voltage doubler to power it on the Vypyr 15).