Wednesday 5 December 2012

Marshall Guvnor

Very similar to the Drive Master posted a couple of days ago, but thought I'd include the full layout to keep things complete.  This version with a diode/LED switch as per a request I had.  If you'd prefer yours to be like the original and have fixed LEDs rather than this switch, then just solder in LEDs directly on the board as per the Drive Master layout.  The 10u cap will need to be moved 3 columns to the right.






34 comments:

  1. I was wondering about this pedal and am very pleased you put it up. I really like the Switch option. Much appreciated. Thanks. (Will Build)

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  2. Awesome, always loved that original Marshall pedal (one in the video). Isn't the Marshall Shredmaster the LED mod you have here. This is next on my list to build.

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    1. Finally built this, sounds wonderfully Marshall! I think I prefer the silicon diodes, but the LEDs (and lifted) also sound great. Thanks for this layout, gonna box this one :)

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  3. Ivlark, I built this pedal and it has great Marsahll tone and sustain but I bypassed your switch configuration and wired the diodes as per the original Schematic. The switch for me did not work and I believe it is wired differently to the original schematic, but being a novice I am quite willing to be proved wrong gracefully.

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    1. The original schematic for the Guvnor has LEDs shunted to ground. The switch allows you to choose whether you have LEDs or silicon diodes shunted to ground to give you a couple of different flavours of distortion (plus the diode lift option). I can't see how it deviates from any of the schematics I have. But thanks for verifying the layout and glad you're liking it.

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  4. Hi guys, I've one question. Regarding the red LEDs, what kind of red LED is it intended to use? 5mm or 3mm? low currant or standard?
    Is it the same?

    Thanks in advance

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  5. Any chance you could work out the Marshall Guv'nor's wayward son the Super Plextortion?

    http://www.diystompboxes.com/smfforum/index.php?topic=77421.msg635337#msg635337

    " . . . basically what you have is a non-inverting gain stage into an inverting gain stage into a baxandall stage into a jfet gain stage. You'll get close by using the marshall guv'nor's first two stages as the clipping. swap out the 680k in the inverting stage via a switch to a 220k/ 470k. baxandall after the led clipping diodes. go from there into a jfet gain stage (1k source). you'll have to dumb down the signal a bit before the jfet gain stage - use a trim pot for maximum effectiveness."

    I'm real interested in a good foundation Marshall in a Box to use with my Bassman LTD and have it down to the DLS mk III and the Plexitortion and want to build both to compare and choose a keeper.

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  6. Hi,
    Built this in a 1590BB as a dual build, along with a Drive Master. There are subtle differences between the two of these, I like using the Guv'nor with lower gain, and the Drive Master with higher gain settings.
    Here's a pic:
    http://imageshack.us/photo/my-images/832/3ush.jpg/
    I included the mods suggested here (it's in French, but the schematics speak for themselves):
    http://optimisetonampli.chez-alice.fr/exemple.htm#guv
    The idea is using an OPA2134 instead of the TL072, and (improving the) decoupling (of) the 4.5V and 9V, to improve the harmonic response. Works great! :)

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    1. Hi,
      I bought the GV1 when it appeared and later I've made the "optimisetonampli" mods too. It is really amazing !
      I recommend !!
      Mine is now True Bypassed as it sucked my tone (mainly on bend) when not engaged.
      Thank you for this so rich blog.
      Emmanuel

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  7. Built and boxed this one. Some great sounds to be had from it that's for sure. Thanks for the layout :)

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  8. I built this up and it sounds amazing. One question though... If I turn up the treble the signal becomes almost non-existent. There's a faint signal, but it's unusable. The pedal works great other than this one issue. It's something I can live with, but I'd love to be getting the most versatility out of this if possible. Does anyone know what might be wrong? Thanks!

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  9. Built one with Wampler Plextortion values, excellent!

    I used the values found here, but went with a JRC4580 and clipping switch: http://img404.imageshack.us/img404/8174/tonepadguvnorwamplerple.jpg

    The guy I made it for said it has kicked his Fulltone OCD off his pedal board.

    https://lh6.googleusercontent.com/-L65G4ylK3B0/VBPxnNJDdlI/AAAAAAAAAOY/JiSdbLlLiM0/w277-h510-no/IMG_20140911_122528_836.jpg

    https://lh5.googleusercontent.com/-xQgwqgxpILY/VBPxPBsj95I/AAAAAAAAAM4/EY3zINvkvaA/w287-h510-no/IMG_20140911_121531_560.jpg

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    1. Where did you find the Wampler Plextortion values? I've seen a couple of variations, which one's did you use?

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  10. Sorry but I could not listen to any soun difference using clipping diodes 1N4148 or the red leds.

    did you feel any sound difference ?

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    1. There should be a decent difference between silicon diodes and LEDs. Listen for a change in the character of the low/mid range. LEDs are generally more 'Marshally'.

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    2. I will try to listen to this low/mid range difference.

      Are there other kind of mods for this clipping stage ?

      Thank you very much.



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  11. I recommend to try infrared diodes. Voltage is lower than reds, so is autput volume, but tone/character is sweeter to my ears than default recommended red LEDs.

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  12. The originals had a built in effects loop. Where would I put it?

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    1. Here.
      http://optimisetonampli.chez-alice.fr/Download/Guvnor_modif.gif

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  13. I've finally built this one yesterday and sounds great! It was tricky to make it fit on a 1590B though. Thanks for the layout!!! PS: This is my first DIY project ever :)

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  14. Such a great pedal! Built it and it worked right away. Sounds great!

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  15. I'm a little confused by the two grounds shown on the board. Does that mean that I need to connect both locations to the negative (ground) of my power supply?

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    1. You can connect one of them to the ground on the mono jack and the other direct to your power supply

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    2. Thanks. I assume that means that the mono jack ground is also connected to the ground on the power supply. It does not appear that the two circuit ground connections are linked onboard. I could just add an onboard link instead of having two separate ground connections to the circuit.

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    3. I'll be building this soon and I'm just gonna jump a wire from one ground strip to the other instead, to minimize wires running to the board.

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    4. I just built it myself and didn't catch this detail until attempting to wire it up. It's the first time I've seen a dual ground connection so it through me a little. I found a good spot to retrofit a link. I think I'll just do that instead of wiring in a ground in two spots.

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    5. yea, it's something that's easily missed. keep in mind though, you can always stretch the board by 1 column and just run a link connecting the 2 ground rows. this way you only need to run 1 wire from the board to a ground location elsewhere.

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  16. Love this circuit. I actually have an original big box Guvnor. Great sounding pedal but it sucks tone in bypass. I can't bring myself to modify it...too valuable. I built this one up and it sounds great. I didn't like the sound of the lift (off) mode on the clipping switch. I change to an ON-ON-ON switch and made the middle position two UV LED's, per a suggestion in the comments. That makes for a nice variation in tone. Definitely going to box this one up.

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  17. Where are the Treb 2 and Level 3? please!!! i cant find it in the drawing.

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    1. It's written in the image: treble 2 to level 3 and that's all you need to do! Cheers

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    2. tHANKS A LOT!!.

      I HAVE ANHOTHER QUESTION...
      THE VOLTAGE OF THE CONDENSATOR 10u AND 100u
      I´LL BE PLEASED ,
      THANK WAGNER

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    3. As this pedal works with 9V input so any capacitor rated for 16V or superior will get the job done. Cheers!

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  18. I would reverse Pole 1 and 3 on the mid as turning it to the right makes it brighter not middier (is that a word?)

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