BOM vs schematic values: Killer Bee

[Anonymous]

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?

[Cybercow]

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.

[Anonymous]

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.

[Author]

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