Saturday 5 May 2012

EHX Screaming Bird

Request.  This layout is based on the schematic for the original Screaming Bird and as such some of the values are a bit unusual today.  Try 2n2 for input and output caps, and 47K and 470K for base resistors.



18 comments:

  1. if it wasn't already, this little guy is verified. it took no time to build, and it sounds pretty good as well. i tried a few transistors, and thought MPSA18 and 2N5088 sounded the best, but i ended up sticking with the 2N5088 for now. also, i know that this is almost the same circuit as the hogs foot, is it possible use this same layout and just change a few values? it seems like your layouts are getting verified as fast as you can post them lately!! keep up the good work. you rock

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    1. Thanks for that. It'll need a couple of columns adding for the Hogs Foot but it's a quicky so I'll do one for it. And yes things are getting verified quickly, it wasn't that long ago that I did a "100th verified layout" thread, it'll be up to 200 in no time at this rate. Hurrah! :o)

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  2. Just finished this, I tried the MPSA18 and stuck with that.. It seems to push it just enough and sounds 'clearer'... Overall it sounds pretty nice. Strips ALOT of bass but I suppose that's what they do... Sounds killer in front of the dirty channel of my Blackstar.

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  3. Just A/B'd with an original Screaming Bird. I couldn't tell them apart. Completely identical :o)

    Definitely recommend trying the MPSA18 for more gain though...

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  4. I just built this, the pot is acting like a volume control although the effect works OK, any ideas what I've done wrong? Cheers!

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  5. I made it. It's an extremely good sounding especially for lighting up humbuckers. It's a treble-middle booster not much of a boost more for a color enlightener if I can put it like that. I recommend this build for build in project with a push-pull pot. :) Cheers

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  6. I just got this built, and it seemed to have slight volume drop even I turned the pot all the way up. This did not happen in hogs foot. The unity volume of hogs foot was at about 1/3 of the boost. Is that normal that screaming bird has volume drop?

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    1. Same here. Dramatic volume drop.

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    2. This comment has been removed by the author.

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  7. could somebody help me out i have tried to make this but it is not working there is no output is turn's mute as i plug in my guitar checked everything nothing is missing but still it is no working

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  8. What would happen if I use 3nF caps instead of the 2nF ones? would it boost another range or something like that?

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    1. They're input and output caps. The larger they are the more bass you'll allow in and out respectively. A small change like that will not have that drastic of an effect on the frequency of the pedal.

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  9. Just wondering what the change to 470K and 47K resistors would change

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  10. I have built a this pedal before from the schematic that is around the internet. In the schematic I've got I have no 47uF electrolytic cap. I tried adding it and I don't notice any difference. Is there any specific reason for it to be there?

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    1. It’s just a filter cap for the power supply. No audible difference but may filter out some noise

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  11. Is there something I’m missing? I’ve built this and have been trying to test it prior to putting it in an enclosure. The volume pot seems to be working, but I’m not getting any guitar output.

    To test, I’ve been doing this…

    +9v going to 9v on board
    -9v going to sleeve of input
    Ground on board going to sleeve of input
    Lug 1 going to sleeve of input
    Sleeve of input going to sleeve of output
    Boost 3 on board going to Lug 3
    Input on board going to tip of input
    Lug 2 going to tip of output

    I’ve also made sure there isn’t any stray solder and have multimetered each row and confirmed they are separate from one another (except for the bottom 3 where I’m using a 2n5088 and getting readings between E,B and B,C).

    Sorry for the novel but it’s got me stumped.

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