Saturday, 21 November 2020

Boss MT-2 Metal Zone

 


 
 

 
 
And since this is a circuit that is popular mod platform, here is the layout with component numbers that matches the factory schematic so you can easily identify which component to sub when following mod suggestions online.
 
EDIT! 201217 
Elijah-Baley have created a great mod sheet! LINK!
So now you can socket the whole board and modify it to your taste. :o)
Demo clip of MTKs build.

 


 

25 comments:

  1. Cool!
    It's the first pedal I bought. When I learnt to build pedal I modded it.
    I'd like to have a stripboard of this circuit, and to use it like a basic to try all possibile mods.
    I'll trace it searching some possibile mistake. But, again, I have to wait to build new circuit.

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    Replies
    1. Nice! Curisous which mods you did.
      I guess tweaking the transistor gyrators (Q2,Q3,Q4) and a clipping diodes is a good start?

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    2. On my original Boss MT-2 I did simply the Diezel Mod.
      But I have a list of mods, and also I started a few of days ago a sort of table of all the possibile mods changing value of caps and resistors.
      I could add it here when I finish it.

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    3. I'll do in a few of days. It's almost done.

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    4. Thats great. I can upload an additional layout with caps and resistor numbers per factory schematic so one can easily identify which parts to sub.

      Delete
  2. Great pedal or... the Greatest Pedal??

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  3. Hey guys, it's been a little while. Hope all is well. You can tag this one, everything works just fine.

    Build folder - https://imgur.com/a/TydQiiD

    Demo - https://www.youtube.com/watch?v=zz9aUegA2QM


    Excellent work on the layout Fuzzhead. It's tidy.

    ReplyDelete
    Replies
    1. Hey, long time, no see, MTK!

      As usual, awesome work.

      Tagged!

      Delete
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  5. Today I wanted to post my instructions to mod this circuit and MTK had just verified it. Good!

    This is the schematic with the instructions to change some value components, and modify gain, bass, treble...

    https://i.imgur.com/Enb7oNK.jpg

    I emulated all the changes individually starting from the original circuit seeing what that change does, so nobody can tell what if you use more change together.
    This not a mod package, or more mod packages, but I put together all parts modified tried in the several mods I found shared in the forums I know.

    I didn't try those in real, I just once modded my original MT-2 with the Diezel mod.

    Don't care about the op-amp you see in my schematic, that's the way I can make the emulation with the software.
    I just left out the diodes mod, but for that I guess the general rules are enough. Let's try alternative silicon diodes, germanium or LEDs (or mosfet?), etc... simmetrical, asymmetrical...

    Tell me if somebody sees some mistake, suggest to us other mods, or tell us your opinion about these mods after you tried it.

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    Replies
    1. Thanks Elijah!
      That looks great!
      I think I will add the link to the post.

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    2. I hope that a lot of people will have fun with it!

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  6. I noticed a little mistake in the layout. The 100pF ceramic cap between Dist 1 and Dist 2,3 have to be placed next the 100k resistor near IC1. Exactly like in the layout with component numbers. And it have to be 47pF, not 100pF.
    MTK should correct its board, too.

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    Replies
    1. Oh yeah, good eyes, man. He's got that cap in the right place on the layout with the component numbers but not the other layout. I'll fix that right away. I wonder if I'll notice a difference.

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    2. Good catch! Layout updated.

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    3. https://i.imgur.com/yyeiviu.jpg Done. Still sounds the same, it's a shred machine. I dig it.

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  8. Hi Fuzzhead, could you post a link to the schematic you used ?
    Thanks

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    Replies
    1. I used the factory schematic but omitted the FET switching and the output buffer.
      https://www.hobby-hour.com/electronics/s/boss-mt2-metal-zone.php
      A easy to read version is the "Vaccine schematic. XD
      https://cdn.mos.cms.futurecdn.net/WxtV5SFshPCY9wSSu5w2iY-970-80.jpg.webp

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    2. Thanks !
      I spotted one mistake on the layout vs schem, C27 (connected to IC1.7) should be 10µ instead of 1µ.
      I'll probe my board and let you know about that volume issue

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    3. BTW that's C11 on Elijah-Baley's schem
      Found the mistake on my build, works fine, sounds great !

      Delete
  9. Hi folks,

    I'm struggling to find the 50K reverse dual gang pot anywhere. Does anyone have a link they can share please? Cheers.

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  10. Built this one last year and it really sounds the way it should be
    More power!

    ReplyDelete