effects circuits design info?

[gotta'58burstonmemind]

Hey everyone, I want to start building my own effects pedals, but I'd like to be able to design my own circuits instead of relying on pre-built pcb's and pedal kits. I bought R.G. Keen's book on PCB design but that only shows PCB design; nothing about understanding the hows and whys of the circuits themselves. Does anyone know how I might get started on learning how to design circuits (or at least guitar pedal specific electrical theory)?

Thanks in advance.

[Mark Hammer]

Read all the stuff at RG's site, all the stuff at Jack Orman's AMZ site, find as many older magazine constuction articles as you can that step you through the circuit in a what-part-does-what fashion, and hang out at the DIY Stompbox forum. While original designs do exist, the lion's share of commercial effects really consist of modifications to known circuits. That's not a diss, merely a recognition that a) a lot of what we, as guitar players, want is based on what is already out there, and b) most pedals include only a limited array of the possibilities inherent in the circuit, such that different "designs" simply make available in product X what was not included in product Y.

That is the long way of saying that you'll find learning how to mod will take you about 80-90% of the way towards what you now consider to be "design".

[52 Bill]

I just suggested this book in another thread, but I found that Walt Jung's Audio Op Amp applications book described all of the basic op amp forms, non-inverting, inverting, differential, single supply, etc.

And with the included formulas, you can understand how component value selection can be used to set gain, frequency response, etc.

When I got this book I could compare some of the circuits to existing commercial designs and understand what they were trying to do. For example, I was fascinated by the fact that the MXR Distortion+ gain control not only changed the gain level of the op amp, but also changed the low frequency cut off point of the circuit, thereby acting as a tone control.

[Merlinb]

Download the stompbox cookbook:
freestompboxes.org ? Login

It has some good info on how various effects are acheived. It's also full of projects, which aren't very practical or well designed, but it's still very informative to see how someone else has acheived certain functions from scratch.

Also check out stompboxology articles:
stompboxology