This is a library of perfboard and single-sided PCB effect layouts for guitar and bass. I'm not an electrical engineer by any stretch of the imagination, just a DIY'er who likes drawing layouts. It is meant for the hobbyist (so commercial use of any of these layout is not allowed without permission) and as a way to give back to the online DIY community.

Wednesday, May 13, 2015

Ross Distortion

The Ross Distortion is very similar to two other famous distortion boxes of the late 70s (MXR Distortion +, DOD 250). However, it uses one side of a 4558 dual opamp instead of the single opamp (741) found in the the other two, and a few other tweaks in component values. There are two versions of this circuit: the Tan version, which uses 2 germanium diodes for clipping (originals used 1N270s, but 1N60Ps or 1N34As should also work just fine), and the Black version, which uses 3 silicon diodes for asymmetrical clipping. I've drawn up 2 layouts for each version, both will fit in a 1590A. The only difference is improved power filtering and added polarity protection in the larger layouts. The yellow 1ยต caps are tantalum.





8 comments:

  1. This comment has been removed by the author.

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  2. Thanks for catching that. Fixed.

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  3. Seeing the early tan version is exactly like an MXR Dist + can you use a 741 chip in it instead?

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    1. In theory yes, but not with this layout as the 4558 is a dual opamp and the 741 is a single. So the pinout is very different. If you want to use the 741 chip, check out the Drivestortion project.

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    2. Would there be much noticeable difference in the sound with the 4558 and 1n914 diodes goat the MXR Dist + uses?

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    3. Not a ton. Just a different "flavor" if you will. That's the great thing about this circuit. There's lots of tweaks you can make to it to fit what you want.

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  4. Damn autocorrect! That.
    Not goats. Not kidding!

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