Right guys, I am looking to buy a book that explains pedals and their workings,from a theoretical point.
I am looking to use this as a reference text now and to start building, or start researching building my own pedal designs rather than just schematics I have found on the internet. I want to understand why various components are preferable to others in various positions etc...anyone know of a book that does this nicely?

I have found many on tube amp building and maintainence, but this is not what I am looking for, I am specifically looking for pedals or effects...

anyone any help?