Tuesday, 19 February 2008
L'Overdrive de la Révolution Trois
The next offering in the "L'Overdrive de la Révolution" Series is here! Trois!
-EDIT-
Scheme typo's updated!
-EDIT 2- 1n4148 diode should be a red LED...
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It's a light overdrive/boost effect (There isn't a great amount a clean headroom here though) utilizing a Jfet stage running into some germanium clippers all cascaded into a common Mosfet gain stage. It's a very dynamic and resposive circuit, I wanted it to be controllable from your guitars volume and tone pots, goals which it definatly scores!
Inspiration for the front end JFET section was taken from the great runoffgroove "Omega" project which is a great versatile booster project which really is worth a build. I loved the way the Omega's "Range" control worked and wanted to see this put into use in an overdrive circuit, a few simple ideas later and here you have it: "L'Overdrive de la Révolution Trois".
There are loads of notes on the schematic image identifying possible mods and changes. A great one is the alternate clipping setup - which I am actually currently using in my build :-)
Give it a try on breadboard, it's a super easy build and a great sound to boot! You won't be dissapointed :-)
Please post any comments, feedback or questions below. Or feel free to email me, my adress is at the top right of the page, don't forget to remove the formatting though! There is also a discussion thread on the http://freestompboxes.org forum, in the "DIY Projects" forum.
Here is a great vero layout from Torchy :-0 Now you have no excuse for not building this ;-)
Hi there, I built this on breadboard, it gives a very clear, soft overdrive that seems to fizz out of the circuit. Quite an exciting character! It cleans up well with the guitar volume too..
ReplyDeleteOne question though, If I wanted to add a Tone control to the cicuit, to roll off treble, where would I add this and what sort of circuit would you recommend?
Thanks for another nice project!
Hello there! It is a quite exciting character that this circuit produces, not a OD tone you often encounter really. An extra mod for you - add a 10KB pot in series with the clipping diodes to alter the structure of the clipping from soft/compressed to open and rangey!
ReplyDeleteA treble roll off control. Hmmm, I'd recommend a SWTC style roll-off control placed after the mosfet stage. Check out muzique.com in the lab pages for info on the SWTC style roll off filter.
You may also find a few buc-ee’s gas station near me
ReplyDeleteeffects builds that I am looking to move on You can always check my account to see what I've got up for grabs.