Monday 3 March 2014

Blackout Effectors Mantra

Apparently another very nice sounding overdrive...



22 comments:

  1. Nice and compact, AND managed to group the pot connections together like a boss. Well done miro!

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  2. thanks a lot man!!! really great layout for an awesome pedal ;)

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  3. Miro, I think it was JohnK that posted a mantra layout to the contributions forum and he had included one with a Low Gain switch mod. Would it be possible for you to post that mod on this layout as well? I agree with John Pinck... nice pot layout. :)

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    1. Eric. The low gain mod didn't work. I asked him to do it based on information from DIYSB Forum and I couldn't get anything out of it.

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    2. Ok nevermind then. Thanks for the update johns.

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    3. No problem. I was hoping that it would and have the low gain mod, but to be honest, I love the regular one so much, I don't think I'm missing anything.

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  4. Damn.. Drew this from the schematic with an error. Sure. It works like it is, but treble control is useless. I'm checking how to fix it...
    +m

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    1. Just posted the fixed version. Volume pot wires aren't as neatly aligned as before, but that should do it. Made a crude fix on my board instead of building a new one. So this is not verified yet. But almost.
      +m

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  5. You can verify it. Sounds great. Treble control works.

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  6. It sure sounds great! Mine has a quite low output (struggling to get unity gain)... any advice on where to look at?

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  7. BTW, on the schematic I'm reading now (by RNFR) R22 (470k at the right of top trimmer on your layout) is after R16 (100k between Bass 2 and Treble 2) while on your layout it appears to be before... maybe it doesn't matter, I don't know...

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  8. OK, I needed to rebias the j201... is it "normal"?

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    1. I agree with you about the 470K resistor, I think that will make a difference because it will change the interaction between the bass and treble pot. I'm sure Miro will be on it when he sees your post. And yes rebiasing the J201 is required more often than not which is why it included the trimmers. Set it to the drain voltages shown on the schematic.

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  9. oooh, thanks! I really thought it was a "set and forget" thing... I might have another look at my crappy sounding dr boogie, then :D

    about the 470k resistor, apparently, the schematic I've been talking about has a mistake... I think that miro has made a layout from the correct one

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  10. Sorry Im new here, where is the output at? Cant figure it out yet? Thanks

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  11. Think this can be verified. Treble works fine. Biased the fets at 4,5 Volts. Bass knob can dial in very much bass, to the level of muddy fuzzyness. Tested with mahogany body with Seymour Duncan '59's; sounds a bit like a Box of Rock to me and notes quickly turn slightly undefined. I prefer it with single coils. Very original sounding effect!

    Thanks Miro!

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    1. Cheers Zick!

      I did build one earlier, but i had to do a crude fix (tm) on the board as i didn't catch the error on the first schematic.. :)
      +m

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  12. any problem on use 200k trimmers instead 150k?

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    1. I bet it'll be fine with 100Ks as well. With 200K, the correct bias may be harder to catch.
      +m

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    2. Thank you Miro, i will go with 100ks

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