Effects database

This is the effects pedal bible with pretty much all of the commercial electronic effects known to man. It has tons of factual information and it is maintained by a very nice guy to boot!

R.G. Keen's website. A lot of info on amps and effects. Check out the "technology
of..." pages.

Dirk Hendrik

Another website dedicated to effects pedals. Again, lots of information and some seldom seen schematics.