This is a library of perfboard and single-sided PCB effect layouts for guitar and bass. I'm not an electrical engineer by any stretch of the imagination, just a DIY'er who likes drawing layouts. It is meant for the hobbyist (so commercial use of any of these layout is not allowed without permission) and as a way to give back to the online DIY community.
Here's a quicky designed by Tim Escobedo. It's an inductor-less wah, and you can use either a pot or an LDR to control the effect. It's small enough to fit in a 1590a if you want a fixed wah in a small package.
Hi there! Sorry for my ignorance but what happens to the signal when the SPST is off? I know this not true bypass. But will my guitar sound be somehow similar when the fixed wah is off? Looks like the signal is going through some resistors, maybe I need to switch on my boost when the effect is off?
The SPST isn't the bypass switch. It just adds some resonance. You'd wire bypass for this like you would most other effects. See the General Layout Notes for a diagram.
Hello guys. I just did one of these using a 100K B pot in place of the VR / LDR and had two problems: 1 - low output volume, even at maximum guitar and amplifier volumes; 2 - the wah effect is almost imperceptible, that is, it varies very little. Would anyone have any idea how to solve this? Thanks in advance.
hi, thank you for your amazing website. i had a question, i made this board but i couldn't find any green ceramic capacitors so i used the red ones instead, would that be ok? also does the voltage of the capacitors matter here? thank you
The green caps are the cheap mylar caps. Red film caps are fine. Cap type is up to you—there's not a right or wrong way usually. Voltage does matter, but usually it's more of an issue with electrolytic caps than the film or ceramic ones. Just make sure everything's above the supply voltage and you should be good. I do recommend using at least 25v electrolytics as I've seen a couple 16v caps explode, even on 9v.
I just made it, and it works on a whole. But in the middle of the sweep there is very loud feedback. When it is in bypass, you can still faintly hear the feedback tones.
Hi! What the LDR value? Thanks!
ReplyDeleteThe schematic didn't really say a value for the LDR. Probably around 500k is a good place to start.
DeleteCan I use a pot instead of the resonance switch? Wich value?
ReplyDeleteA pot might not do much more than the switch as it's only grounding a small value cap. You'll have to experiment with the value.
DeleteAnother stupid question:in which way can I turn this wah,which is basically a lo-pass filter,in a hi-pass filter? Is it possible?
ReplyDeleteHi there! Sorry for my ignorance but what happens to the signal when the SPST is off? I know this not true bypass. But will my guitar sound be somehow similar when the fixed wah is off? Looks like the signal is going through some resistors, maybe I need to switch on my boost when the effect is off?
ReplyDeletethanks!
The SPST isn't the bypass switch. It just adds some resonance. You'd wire bypass for this like you would most other effects. See the General Layout Notes for a diagram.
DeleteMy bad! Now everything is clear. Thanks man!
DeleteEtched a PCB and put one for myself - it works: can be marked as verified
ReplyDeleteThanks for verifying!
DeleteHello guys.
ReplyDeleteI just did one of these using a 100K B pot in place of the VR / LDR and had two problems:
1 - low output volume, even at maximum guitar and amplifier volumes;
2 - the wah effect is almost imperceptible, that is, it varies very little.
Would anyone have any idea how to solve this?
Thanks in advance.
hi, thank you for your amazing website. i had a question, i made this board but i couldn't find any green ceramic capacitors so i used the red ones instead, would that be ok?
ReplyDeletealso does the voltage of the capacitors matter here?
thank you
The green caps are the cheap mylar caps. Red film caps are fine. Cap type is up to you—there's not a right or wrong way usually. Voltage does matter, but usually it's more of an issue with electrolytic caps than the film or ceramic ones. Just make sure everything's above the supply voltage and you should be good. I do recommend using at least 25v electrolytics as I've seen a couple 16v caps explode, even on 9v.
DeleteI just made it, and it works on a whole. But in the middle of the sweep there is very loud feedback. When it is in bypass, you can still faintly hear the feedback tones.
ReplyDelete