Sunday 8 September 2013

MXR Custom Badass Modified O.D.

Next up in the MXR Custom Badass line is the Modified Overdrive—a classic overdrive circuit with modern modifications for improved performance and versatility.

For added flexibility, we’ve added a 100HZ cut and boost control that allows for a more focused EQ when cut, or a beefier tone when boosted. The Bump switch engages an alternate EQ voicing that boosts the lows and mids. Put it in front of the '78 Custom Badass Distortion for a slew of amp-like gain structures that won't mask your tone.

Experience overdrive nirvana courtesy of the MXR Custom Badass team.

“My tone has never been better, and I ain't just sayin that. That Badass Overdrive is THE BEST distortion tone I’ve ever had. Its amazing!” - Nashville session ace Chuck Ward.


Couple of the values may seem a bit off, so use the closest ones you have, like 27n for stated 28n and so on.


38 comments:

  1. Replies
    1. Thanks. Got them done after a bit of hair pulling. Had to do them both to avoid the "Cool! Could we have the Distortion too?!?!" -comments. :P
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  2. I want to build this one but after looking at the schematic, I'm going to have to go over your vero first (since it isn't verified yet). I can already see that the 240K input resistor (R13) on your vero is incorrect. it's supposed to be 10K. the 240K (R17) resistor is in the power supply and is connected to U2 which i'm assuming is a 9V regulator judging by Ice-9's symbol, but I don't see one of those on your vero and a regualtor probably isn't needed anyway.

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    1. Please do.

      The schematic and the BOM made it harder to read than usual, so there could be other similar mistakes. I'm fairly confident about the topology though. I'll update the input resistor...
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    2. And yes - i omitted the regulator and the diodes from in/out.
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  3. well, I looked it over pretty carefully and didn't see any other errors so i'm going to try and build it up tonight. there's also a couple of 100n caps on the power supply that you left out for RF filtering but IMO, they're probably not necessary at all. there is room on your vero layout for them so I might end up adding them anyway.

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    1. The filtering felt a bit excessive, as 100n + 100µ will result in 100.1µ total. I usually leave filterin in tact if the other cap is something like 100p - then it will affect different parts of the supply noise. In this situation i strongly feel there's no audible difference whether the filter cap is valued at 100µ or 100.1µ.

      Let us know if it works.

      Like stated, some of the cap values are a bit strange...
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    2. well, since the 100n's are non-polarized, it really not their value added to the 100u that's is what makes them an added filter. they're mainly there for RF and not for filtering ripple.

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    3. True. But in my experience the rf filter caps are usually way smaller. Either way, i don't think you can hear any difference with or without the 100n caps on the filters.
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  4. Just created a demo review for this pedal. Pretty nice one, good controls (100hz and bump). Much better then the 78 Distortion which I couldn't get any decent tone out of.

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    1. Here's my review: http://www.youtube.com/watch?v=h0C9UkCPUVM&feature=c4-overview-vl&list=PLit6yWnMfIIn2KB_2bL8Tl-rzWW3ja8IU

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  5. built it but i'm not getting anything out of it yet.
    I've gone over the schematic and compared it to the vero a bunch of times and miro's vero looks 100% correct to me.
    when I crank my amp, I can hear the gain, 100hz, tone control, and volume controls all working properly but it seems to not be getting any signal into it. i'll probe it tomorrow to see where it's not getting thru.

    BTW, I believe that the transistor is supposed to be an MPSA14 but mine's not working with either the A14 or the A18 yet.

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    1. Take your time and let us know. Thanks man.
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  6. tag it! it works great. before I test my builds, i always run a triangular jeweler's file down the rows, then with an .024" guitar nut file, followed by a fine brass brush to make sure that there are NO shorts between the rows, but after putting on the scope with a signal generator, I found that the signal disappeared on the base side of the 47n input cap. well, it turns out that there was a microscopic (and I mean microscopic!) solder bridge. once I fixed that she fired right up.

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    1. What do you think about it John? I thought it was pretty good. Have used it live in a demo and just created a video demo for it.

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    2. I think that it sounds great. i'm very impressed with it.

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    3. hola John Kallas osea que el veroboard publicado arriba por mirosol es 100% funcional???

      Hello John Kallas bone above the veroboard published by mirosol is 100 % functional ???

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  7. pic of my perfectly working circuitboard:

    http://johnkvintageguitars.homestead.com/Effects/Fuzz-ODs/MXR-CBMOD/MXRCBMOD-circuit.jpg

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    1. Excellect! With a Capital E! I'll tag it right away!

      Amazing looking board too.

      To be honest i was a bit afraid of the schem, because the cap values don't look ok at all. Great to hear it's running as it should.
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  8. the ONLY cap values that are different on mine are that I used a 27n for the 28n and a 2u2 + 1u (=3u2) for the 3u3. I had to use a 100K + a 10K resistor in series for the 110K one, and a 22K + 2K in series for the 24K one, so mine should be pretty darn close to the original.

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  9. is this thing about the same thing as the Way Huge Green Rhino?
    Demos sound good...another one to add to the list LOL

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  10. DONE!

    pics:

    http://johnkvintageguitars.homestead.com/Effects/Fuzz-ODs/MXR-CBMOD/MXRCBMOD-01.jpg

    http://johnkvintageguitars.homestead.com/Effects/Fuzz-ODs/MXR-CBMOD/MXRCBMOD-02.jpg

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    1. Looking perfect once again!
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    2. Looking very cool! How do you get your enclosures so shiny? Polish them with a machine?

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    3. I sand them with a Makita sander and then polish them on a buffing wheel.

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    4. Hey John, good looking board & pedal!
      I was thinking either to get some waterslide decal papers or label maker like yours. But I've seen some waterslide papers "yellowed" after some time. Does your labels stay clean or "yellow" after awhile. Thanks.

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    5. the labels never yellow. I have some that are more than 20 years old and they look the same as the day that I applied them.

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    6. What labeler and tape are you using John?

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  11. Custom Power Supply
    Loved this article. Would surely take the advantage.

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  12. Does anyone have the actual schematic for the M77 pedal... my Google search has been less than fruitful.

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  13. Hi. someone else finish it ? There are some sample audio ?. Recommend this project? Thank you

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    1. i've build this 3 times. great effect.go for it. i've also compered it with the original at a local shop and the "expert" at guitars and pedals that was working there could tell any difference.

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    2. edit: couldn't tell any difference...it was like 99% to mine and his ears

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  14. This comment has been removed by the author.

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  15. Hi guys, my MXR is not working at all. Can I post some pictures or get PM with soome solutions? What Output values should I get? What Ive found out is, that when I turn it on with switch, I get strong sound kick in my combo and volume drops down (lets say 30 percent). Thank you guys.

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