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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.






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29 comments:

  1. glasspak7310 October 2015 at 21:40

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

    ReplyDelete
  2. Zach11 October 2015 at 08:57

    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.

    ReplyDelete
    Replies
    1. Zach11 October 2015 at 09:06

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

      Delete
  3. Merhulsky11 October 2015 at 17:51

    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.

    ReplyDelete
  4. BRE17 October 2015 at 07:04

    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 (http://www.synfo.nl/servicemanuals/Maestro/MAESTRO-PARAMETRIC-FILTER_SERVICE_MANUAL.pdf), 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!

    ReplyDelete
    Replies
    1. Alex17 October 2015 at 13:15

      Hi Bre.
      I've used this schematic:
      http://s158.photobucket.com/user/PrehistoricFuzz/media/66D11D96-A714-456C-969E-59695456EDEB-2620-0000034CD1E391CC.jpg.html
      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! :)

      Delete
    2. BRE18 October 2015 at 17:50

      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!

      Delete
  5. Mike25 October 2015 at 02:58

    How are switches wired

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    Replies
    1. Hozy3125 October 2015 at 18:08

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

      1
      2
      3

      1--4
      2--5
      3--6

      1--4--7
      2--5--8
      3--6--9

      Delete
    2. Mike30 October 2015 at 10:27

      Thanks for that

      Delete
  6. Hozy3125 October 2015 at 18:09

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

    ReplyDelete
  7. Unknown27 October 2015 at 19:23

    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.

    ReplyDelete
  8. Anonymous7 November 2015 at 05:10

    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?

    ReplyDelete
  9. Alex7 November 2015 at 10:04

    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?
    https://www.youtube.com/watch?v=w4Qzptnrjgc

    ReplyDelete
  10. Anonymous6 September 2016 at 17:52

    This comment has been removed by the author.

    ReplyDelete
  11. Unknown3 April 2017 at 00:23

    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?
    Thanks

    ReplyDelete
    Replies
    1. Unknown3 April 2017 at 11:51

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

      Delete
    2. Unknown14 April 2018 at 04:03

      I'm wondering about that too.

      Delete
  12. sha3313 April 2017 at 14:02

    Hi !

    How is the dual C100k wired/numbered? Thanks

    ReplyDelete
  13. acidophilus18 January 2018 at 21:24

    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

    ReplyDelete
    Replies
    1. Sage25 March 2018 at 06:58

      Yeah, I had the same problem. It turns out the Frequency pot is misnumbered; it's backwards compared to the offline wiring guide. Swap terminals 1 and 3, and swap terminals 4 and 6, and everything should work properly.

      Delete
  14. Unknown29 August 2018 at 22:18

    Just finished up this build and I'm very happy with it. Aside from a couple of mistakes on my part, it went pretty smooth.
    It really takes my Fuzz Factory to a new level...

    ReplyDelete
  15. Mulekicker5 February 2020 at 01:27

    I built this awhile ago and just pulled it back out. Anyone else feel the taper is off on the height control? Unless it's pretty much cranked I can't hear much change while turning the frequency knob (on my build anyway).

    ReplyDelete
    Replies
    1. Sage13 April 2021 at 05:56

      Yes, that's due to the use of a linear pot for the height control. The original schematic called for an S-taper pot, which isn't commonly available in 10k. Must've been a custom part. I decided I didn't ever need to cut frequencies since I only use this pedal as a midrange boost. So I swapped the 10k linear pot for a 5k resistor in line with a 5k audio-taper pot. Not only does this fix the taper, but it gives me the full range of the knob (instead of just the upper half) to adjust the amount of gain with greater precision.

      Delete
  16. Sami25 April 2020 at 08:14

    I'm having somewhat similar problem but height cuts off volume totally when it is turned lower.

    ReplyDelete
  17. zosotone10 February 2022 at 14:47

    Maybe the gain pot-trimmer it’s about the R8 resistor 2k2 before the diodes. Try a 10k pot. It’s the output of IC1A.

    ReplyDelete
  18. Albert4 September 2022 at 20:37

    heres some info on converting a liner pot to a log anti-log pot (w taper) like in the original: https://electro-music.com/forum/phpbb-files/pot_taper_amz_168.pdf

    ReplyDelete
  19. Albert4 September 2022 at 20:41

    This comment has been removed by the author.

    ReplyDelete
  20. Albert12 September 2022 at 21:32

    after some experimenting I found replacing the 5k6 resistor with a 20kb pot in series with a low ohm resistor to ground acts as a usable gain control for the overdrive side

    ReplyDelete