Saturday, 10 October 2015

Maestro MPF-1

17/10/2015: Layout updated and verified!
Changed 2 components values and added an extra capacitor on Bre's suggestion.
Thanks to Bre for the help and for verifying this!
- Changed 22u cap from pin9 to 2u2.
- Added a 2u2 cap between diodes and ground.
- Changed 4007N to 4007UBE.


  1. Can i use a CD4007UBE inplace of the 4007a? Thank you for this circuit

  2. great job on this one alex. that video is awesome too, it just sounds awesome. the other pedal really added something special to the MPF-1, i wonder what the other pedal is, i could barely make it out.

    1. after searching through his videos i found it. it's a harmonic percolator for those who were curious too.

  3. No way!!!? Awsome!!! Wanted to give a stripboard Version from stomobox forum a try one week ago. Guys, you really read my mind!!! Thanks a thousand.

  4. Thank you very much Alex for this layout!
    I've just finished it and it works from the first try on clean setting, but the overdrive setting was very weak. Looking at the schematic (, I found 2 little errors in your layout:
    1. the 22uF must be 2.2uF
    2. the diodes must be grounded through a 2.2uF, not directly as you did
    3. the IC is not a CD4007n, it must be a CD4007AE (as in the original schematic) or, more easy to find, CD4007UBE.

    After these mods, the overdrive part sounds very good (as in the clips from Youtube) and, more important, it's the BEST OVERDRIVE that I heard!!!

    Thank you very much again!

    1. Hi Bre.
      I've used this schematic:
      Did you use a CD4007UBE?
      If you say it sounds more like the original, I'll add them to the layout.
      Thanks for the help! :)

    2. Hi Alex!

      The schematic you have used has some minor errors: the ones that I mentioned above :) I didn't check yet all the schematic from the service manual of MPF (which i consider to be correct) against the one you used or against your layout, but I will do I soon I will have some time.
      I didn't find anywhere informations about CD4007N (it seems that it doesn't exist) you mentioned in your layout and CD4007AE from the original schematic is unavailable, so I found the closest to it is CD4007UBE. Anyway, it works great :)

      Thank you again for your work! It's an amazing overdrive!

  5. Replies
    1. Switches are wired as so with holes facing up. Check the offboard wiring guide on the main site for more help.




  6. Built this and really liking it. Nice addition to my filters.

  7. how difficult would it be to allow for external/expression/CV control of the dual frequency pot?... is it as easy as changing the on-board dual pot to a jack and plugging an exp w a dual pot at the treadle into the just-installed jack? it's got to be more complicated than that, especially with a dual pot. I'd love to be able to sweep through the frequency range of this pedal.

  8. I built it, too. It works really well, but the overdrive is still not as strong as what I'm hearing in the YouTube demos... Even with the updated changes. Is there anything else I can try swapping out to get it to sound more like the original?

  9. It's not supposed to be a strong overdrive.
    It's supposed to be used after a fuzz or an overdrive (like in the video).
    Does it sound weaker than the one in this video?

  10. This comment has been removed by the author.

  11. Hi! I make this fantastic pedal!One question: it's possible to add a gain/drive pot to control the overdrive in overdrive mode? (As in Stone deaf pdf-2) che
    How Can i make this?

    1. or is there any solution to solve the drop volume in overdrive mode?

  12. Hi !

    How is the dual C100k wired/numbered? Thanks

  13. Built it and and I´m enjoying it. But there is an issue with the frequency pot, which only works audibly in the first quarter of turn (from 5kHz to 50 Hz). The rest of the travel it stays around 50 Hz. Anybody else experiencing this problem? Cheers