Circuit types

Started by greigoroth, December 18, 2010, 12:44:55 PM

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greigoroth

Hi!

I've tried the search function, but to no avail. I understand that many commercial pedals are basically variations on a number of basic circuits or circuit blocks. Does anyone know of a site/thread/list of pedals that fall under certain circuit types? That was a really badly worded question, so maybe I'll give an example:

TS type circuits:
Landgr@ff OD
Boiling Point (with Dragonfly swirls!)
Fulldrive

RAT type of circuits
CMATmods Black Plague

....

For a beginner such as myself a thread/list like this would be great. I don't know enough about circuits (yet) to recognise topologies, so it would be cool if I am browsing pedal demos on youtube, or checking out a favourite guitarist's rig and find a sound I like,  I can check out "the list" and go "ok, if I like that I should look at a tubescreamer type of circuit".

???
Built: GGG Green Ringer

edvard

As far as "topologies" go, what you're talking about is the kind of circuits that were known for years as "cookbook" circuits...
Snippets of circuits reprinted in a hundred electronics encyclopedias, magazine articles, application notes, etc. for folks to mix and match.

Two most common types of op-amp distortion circuits are to be found most famously in the DOD 250 and the MXR Dist+.
Both are op-amp based, one uses diode clipping in the op-amp feedback path, the other in the signal path after the op-amp.

The Tube Screamer is of the variety that has clipping diodes in the feedback path, followed by an active high-pass shelving type tone control.
The transistor circuits at the head and tail are typical "common-emitter" types that provide unity-gain buffering for the JFET switching system.
Many people claim that the buffers hold the "secret" to the sound of the TS, with the "best" being the TS808 variety, while others say leaving off the buffers doesn't do anything substantial to the sound, and the many, many clones with varying degrees of faithfulness to the original circuit all stand as testaments to each one's particular claim..

Now, back to your original question... ;)
The "list" you speak of can be found at DiscoFreq's Effects Database:
http://www.effectsdatabase.com/model/ibanez/808/ts808
(see "Related" at the bottom of the page  :icon_eek: )

Look up other vintage pedals and you'll get similar lists, many with schematics:
Big Muff: http://www.effectsdatabase.com/model/eh/bigmuffpi
Fuzz Face: http://www.effectsdatabase.com/model/arbiter/fuzzface

Have fun!!
All children left unattended will be given a mocha and a puppy

greigoroth

Built: GGG Green Ringer