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, March 9, 2016

MXR Noise Gate

Got a request for this one. The schematics that come up with a Google search are all wrong apparently, but it looks like the good people on FSB have figured things out. Here's a link the the discussion and the latest schematic (which this layout is based on) is on page 5. I based this layout on the original layout from MXR, using 2, single op amps. Early versions used the 741 chip, but you can use TL061 or 71s if you want.



41 comments:

  1. yes, my request. thank you so much.
    awesome as usual!

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    1. No, unfortunately. but i'm planning on doing it next week.

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    2. I have built one, i use 2n5457 rotate 180 degree, and i love this, very nice pedal.

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  2. i have build it,but it doesn't work, it is humming, can you tell me what's matter?

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    1. i tried the one from Tonepad, seems like they are similar. doesn't work

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    2. report? mate?
      what components u are using?

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  3. hi guys, I want to build this project but .. can i replace the 741IC ( UA741CP ) to NE5534 IC ?? Thanks!!

    datasheet
    http://www.alldatasheet.com/datasheet-pdf/pdf/25580/STMICROELECTRONICS/UA741CP.html
    http://www.taydaelectronics.com/datasheets/A-250.pdf

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    1. An NE5534 is a good replacement for the 741.

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  4. I have tried it and found a mistake. Pins of Q2 are ordered in the wrong way. It should be SDG, not DGS. So change two pins of the transistor, it works great..

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    1. And you can use BF245C for 2N5952.

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    2. i followed your suggestion, and didn't work

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    3. The pinout indicated in the layout is correct. See the datasheet for the 5952.

      https://www.fairchildsemi.com/datasheets/2N/2N5952.pdf

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  5. Can i use j201 por 2n5457 instead of the 2n5952???? Thanks

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    1. I have done the tonepad version more than 10 times and I have not had problems, some values ​​are wrong I have videos on my youtube page of this pedal running at 100%, no transistors are needed
      Matched, no special capacitors are needed, this pedal does not need anything special, just having the correct values
      Look at the demos on my channel, excuse my English, I only speak Spanish https://www.youtube.com/watch?v=tq_GotkLN5k

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  6. Hi, have the PCB and layout be amended to reflect Göktürk's findings of SDG 'round the wrong way?

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    1. That transistor is oriented correctly. See comment above.

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  7. All, it seems this is a problematic circuit for the DIY community–on this blog and elsewhere. If you build it there's a good chance your troubleshooting skills will be tested. Here's the schematic the layout is based on for reference.

    http://s33.postimg.org/c3opxdipr/mxr_noise_gate.gif

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    1. hello The layout of tonepad noise gate 2 has certain errors which must be corrected in the following way:
      1) Input resistance is 10K (not 1k) Input cap is 10n (not 47n)
      2) The famous unpolarized cap of 1uf is not such in the original is 10n
      3) The cap of 10uf that is between the R of 1M going to vb and that of 22k that leaves the emitter of q1 is inverted goes with the (+) side towards the fet (as it is in the layout).
      4) The output cap is 10uf (not 1uf).
      5) use the FET 2n5485 (see the datasheet and place it correctly) and two 2n3094 (do not check the hfe, any one serves)
      6) The potentiometer of the first noise of the video is logarithmic so it fits faster, the second one is not so the adjustment must be more precise, it does not take more than 5 seconds to leave it ready, both work the same
      7) The noise gate pedal of this model (in others it varies the position like the dod fx30) must go after the distortions and before the effects, the noise gate works best in that position
      9) IMPORTANT: USE A 6.2V ZENER IN4735 DIODE, WITH THE 5.1 ​​DOES NOT WORK
      9) The mods do not work, I have tried them and they are not recommended for a musical use, they reduce volume and cause the pedal to work strange and does not comply with the noise gate function, you are free to experiment but I save you the work
      10) In my experience doing pedals many schemes have intentional errors maybe so that the brands can protect their products and make it difficult for someone to clone them, I have seen volt transistors, inverted operations, unspecified resistances etc, in schematics and layouts so it is not Surprise that tonepad has modified it a little to not interfere with the rights of MXR knowing that at some point people would realize that corrections to achieve amr the pedal

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  8. thank you! Seems like this one will be a challenge. One thing is that the 2N3904s should be matched.

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  9. update?
    still cant make mine work

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  10. Hello ! What should be the size of board Thanks !

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  11. Hello ! What should be the size of board Thanks !

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  12. This scheme is checked? And it is working?

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  13. I think the hfe on the trannies should be matched, doesn´t matter the value, just matched. I had problems with the tonepad one and that was the issue. Try it!

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    1. I have done the tonepad version more than 10 times and I have not had problems, some values ​​are wrong I have videos on my youtube page of this pedal running at 100%, no transistors are needed
      Matched, no special capacitors are needed, this pedal does not need anything special, just having the correct values
      Look at the demos on my channel, excuse my English, I only speak Spanish https://www.youtube.com/watch?v=tq_GotkLN5k

      Delete
  14. There is a Polish version with 1 IC that seems to work properly. I tried this page's layout twice without success... , so I think I'll try this Polish fixed one and let you know. The layout is not as glamourous as this, but with a couple fixes I think I'll mount it. I'll let you all know!! Cheers

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  15. Verified the perfboard layout. https://youtu.be/ZOm0D_rBFno

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    1. Really? All of us were failed before. Any mod?

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    2. None. The FET I used was a 2n5485 I think.
      Funny, if that number on the 741 chip with the square notch in my video is a date code, its older than I am. It hasn't seen life in decades!

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  16. Apparently is working fine the perfboard layout, the only change i made was the recommendation on the Zener, i used a 6.2V zener instead of the 5.1v. An also i check all the recommendations from Dan are applied on this version but the zener one.

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    1. Forgot to say i also use 2n5485, just inverse the transistor.

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  17. If we wanted to add an LED where could we put it into this circuit so it goes off when not gating and on when gating? Thanks for all the layouts they are awesome!!

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    1. You're going to have to give that one a Google, cuz honestly, I have no idea. haha

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