Howdy Y'all. I've been building a few pedals from PCBs lately and I've been having a really fun jolly time. However, I don't think I've really gotten a great understanding of what's going on and why inside of these, and would love some friendly help along my way.
So for example! I've just finished a really simple Sho Nuff that I bought from GuitarPBC.com, the schematic and layout can be found here: http://www.guitarpcb.com/PDF%20Files/SHO_v2.pdf
I really love the sound of this pedal when it's cranked all the way to the right on both knobs, lots of fuzz, but also, with that, lots of volume. I love the fuzz it gives but I'm just don't want a signal that loud when I'm done with it.
So I know most likely everybody can tell me how to do this, but what interests me more than just what to replace or what to install is why exactly it's doing what it does.
Thanks!
Beginner Mod Question!
That pedal is a (mostly) clean booster - if you search on this forum for "super hard on" you'll find a huge amount of discussion on how it works.
Unfortunately I expect the cool sounds you are getting from it are mostly due to the input of your amp being hit by a much more amplified signal than it's used to (this pedal can push he cleanest of clean amps into distortion). So you can't reduce the volume and still get the same sound, unless you turn down your amp!
A quick note - if you look at the far right of the schematic, you see 'p2'? That's a potentiometer. You will see that lug 3 comes from the effects circuit, lug 2 goes to the output, and lug 1 goes to ground. That means that this pot is acting simply as a volume control, dividing the signal between the output and ground depending on where the pot is set. So you've already got your way of reducing volume right there!
Broadly speaking such a volume control doesn't have any effect on the sound except to make it quieter (in reality it does have a small effect due to changing the output impedance, but that's another story).
Unfortunately I expect the cool sounds you are getting from it are mostly due to the input of your amp being hit by a much more amplified signal than it's used to (this pedal can push he cleanest of clean amps into distortion). So you can't reduce the volume and still get the same sound, unless you turn down your amp!
A quick note - if you look at the far right of the schematic, you see 'p2'? That's a potentiometer. You will see that lug 3 comes from the effects circuit, lug 2 goes to the output, and lug 1 goes to ground. That means that this pot is acting simply as a volume control, dividing the signal between the output and ground depending on where the pot is set. So you've already got your way of reducing volume right there!
Broadly speaking such a volume control doesn't have any effect on the sound except to make it quieter (in reality it does have a small effect due to changing the output impedance, but that's another story).
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astrobass
- Cap Cooler
That type of volume control does also roll off highs to an extent the same way a guitar's volume control does. Depending on the nature of your effect, this may or may not be obvious.
For instance, the Electra distortion effect (a GREAT second step into effects!) and all of the silicon fuzz face variants (also an awesome place to play around) I've played with are at least pretty obviously affected. The BMP and TS circuits are not obviously affected by it.
I believe you can address the issue the same way you would with a guitar volume pot (treble bleed mod), but where it's noticeable, it's usually actually useful to get some extra tonal range out of the effect.
For instance, the Electra distortion effect (a GREAT second step into effects!) and all of the silicon fuzz face variants (also an awesome place to play around) I've played with are at least pretty obviously affected. The BMP and TS circuits are not obviously affected by it.
I believe you can address the issue the same way you would with a guitar volume pot (treble bleed mod), but where it's noticeable, it's usually actually useful to get some extra tonal range out of the effect.