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  • July 3, 2021 at 12:02 pm #19519
    Anonymous
    Inactive

    Hello all! Just finished the Killer Bee but as I was looking around the document, after having already built it, I noticed the schematic in the build documents shows several components that are very different than the bill of materials. I followed the bill of materials, it still works, but gain knob doesn’t change anything from 0.5 to 10, and there’s a lot of low end.

    any idea if the difference in value is the reason why?

    Here are some differences I found between BOM and schematic. BOM is listed first.

    BOM ———Schematic

    R2:

    • 360k ———470k

    R3:

    • 18k ———15k

    R4:

    • 3k ———18k

    R5:

    • 1k ———2k2

    R11:

    • 5k6 ———6k8

    C3:

    • 220n ———470n

    C10:

    • 4n7 ———100n

    C13:

    • 100n ———22n

    C15:

    • 22u ———2u2

    Here is a link to the build document if that helps

    https://guitarpcb.com/wp-content/uploads/2018/06/BD_Killer-Bee.pdf

     

    are these huge differences, big enough to worry about?

    July 3, 2021 at 12:45 pm #19520
    Cybercow
    Participant

    Going with the BOM is Barry’s rule of thumb. So you did right.

    As for the gain control, (I know bot the BOM and schematic say B500K), a B1M will work too, provide a tad more gain and work across more of the sweep. Or you could increase the value of R4 back to the schematic’s 18K or higher. (Remember, the higher the resistance in the feedback loop of that opamp, the more gain.)

    I know the change in C3 (from 470nF to 220nF) improves the range of the tone sweep.

    Changing (experimenting with) the value of C15 will result in a change of the darkness or brightness of the final dirt stage.

    July 3, 2021 at 3:47 pm #19526
    Anonymous
    Inactive

    Thanks Cybercow! I’m definitely going to try to change the gain pot, it worked wonders for my Diamond drive build. I’ll see what else I can come up with. Pedal sound good already, just a bit different than my Honey Bee. I’ll play around with it.

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