Tuesday, 22 January 2013

Briggs' E11even

From Mr. Briggs: And here's the last in my series of Fender / Vox / Marshall themed boosters/overdrives - The "E11even" (Spinal Tap reference intentional). It's designed for those classic Marshall overdrive tones, plexi / jtm45 sort of stuff. It's based around the old mosfet booster design I love with a few tweaks. The bias control is essentailly a saturation control for those diodes, setting it high gives you more headroom and a smoother more spanky (hehe) overdrive, a lower setting gives a more gritty tone. The Body control allows you to alter the bass content and overall frequency gain structure of the circuit. When the body is at 470k you've got the classic Marshall mid/high boost filter (almost, with that 1M resistor to ground you don't quite get the same level of low end roll off but it works with this setup). One suggestion I have for a mod is placing the saturation control over one diode only so that you can dial in some really interesting (and extreme!) asymmetrical clipping structures...
For the protection diode you can use a 12v zener or just a red LED. I use a 470kB (linear taper) pot for the Body control but some may like the taper of a log pot here - it's up to you...


MAndrews tipped me off about Geiri's excellent demo videos. First with strat and single coils, then with Les Paul and 'buckers:



11 comments:

  1. Some demo links:
    Strat; http://youtu.be/WMh9mvB9lvc
    Les Paul; http://youtu.be/h-cgwKqJQKU

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    1. Thanks for the links. I was busy and didn'y really look for them :)

      I'll add those both to the post...
      +m

      Delete
  2. Hey those are my videos hah! It's a great pedal!

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    1. :DDDDD

      Maybe i'll add some credits :)
      +m

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  3. Don't worry, you don't need to credit me at all. I do have a bunch of video demos of various pedals that I made from layouts here. Want me to list them for you to put with layouts? I think people really appreciate being able to hear a demo to at least hear the type of sound. It will of course sound different through other gear but gives an idea.

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    1. Thanks for the links! I'll add those to corresponding posts during the day. Right now - power nap. :)
      +m

      Delete
  4. Should be 470p, not 47p :-)

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  5. Made this and worked but didn't keep as there is a stack of other boosts that I've got and I don't need any more.

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  6. I think this one needs to be tagged as "verified"! ;)

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  7. BTW, I was revisiting my build today and noticed the gain control needs to be reversed ;). This little circuit doesn't do bad even when compared side by side with a ROG Eighteen or a Plexi-Drive, IMO.

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