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i have this "guitar pedal" i want to build and im not too sure about my design would somebody help me with this? Answered

so my "guitar pedal" is basicly tone from a guitar copied 3 times and put in a box with some fancey led lighting. i have a few questions
1- does the type of capacitor make a differance as far as sound goes
2-ill need help with my wireng diagram
-the diagram doesnt show it but all the switches (except for SW4) are double poled
-LED 4 is a four pronged led



7 years ago

I assume you want to switch between each of the RC circuits to create some sort of low-pass (high-cut) tone control. Offhand, there are a few problems...

-- The cap values are way off. Using any of the values in the diagram will reduce the signal to mud. Appropriate values for tone caps are more like 0.01uF, 0.022uF,  0.033uF or 0.047uF.

That's about 1/1000 less capacitance than show on the drawing.

Any sort of film cap (mylar, polypro, polyester) will work, or even a ceramic. Traditionally they were rated for high voltage, but that's not really necessary; any non-polarized cap with a voltage rating above 10V should work fine.

-- Breadboard this before building, to test the RC filter values. This is wired somewhat differently than the passive tone control in most guitars...

-- If you want LED indicators, you'll need to keep the LED circuit isolated from the audio signal. You can use double-pole switches to do that. Two separate circuits will work fine here.

ok so i assume the caps i pulled from an old television wont aork for this at all right?

so the tone is effected by the cap's UF value and not what its made of right?

i will definatly breadboard this since it is one of the most somplex circuits ive ever built

i tried to show a doulbe poled switch but ACAD E wont let me show it but yes the are double poled

i also for got to mention that ill need a way to bypass the tone caps like a regular pedal would

I don't know if your used caps have the correct capacitance value, but caps tend to have a finite lifespan. I'd go with new ones. They are inexpensive, so that shouldn't be a problem.

Yes, it's the uF value. Some will argue there are audible differences between types, but it's very slight, if at all.



Each double-pole switch would seem to have an "Off" position, so if they are all off, then the effect is bypassed. Otherwise, you'll have to add a standard stompbox footswitch to bypass the whole thing.

the caps are rated what is shown anyway so they already wont work for this

ok so what cap is the best for this ?

yes thay have ON-OFF-ON switch layout so i will make one side at a lower value to make it
but what i want to do with this is make it so i can go from "clean to dirty" so to speak

i also need the stereo jacks to turn on the lights useing the yellow wire that isnt connected to anything in this picture so i can unplug the chord and the lights will turn off

OK, get some new ones. I don't think it's critical what type you use. Here's some appropriate caps: Allelectronics.  Any of those types will work--chose the right capacitance value, though. (Ceramics would be low on the list, though.)

Another way to look at this: Why use three different value caps?

A typical tone control uses one cap and a POT for a large range of tonal adjustment. What changes is the resistance, not the capacitance. I'd use three 250K (or 500K) trim POTs instead of fixed resistors, and chose one cap.

It doesn't really matter so much if you wire-in three different caps, or if you connect only one cap to each of the three resistance networks. The results will be different, but with trim POTs you could dial in the effect either way. Plus, in either wiring, using more than one switch in the ON position will ADD the filters together. I.E., you have to think binary here--three RC networks with three switches is eight different combinations...

For three filters, you don't need three ON-OFF-ON , just three ON-OFF. A single ON-OFF-ON switch could control two different RC networks, but they wouldn't be additive. Two ON-OFF-ON switches would control four different RC filters, three switches would control six different networks. And filter groupings fromthe different switches would be additive.

Yes, using a stereo jack to switch off the LED battery is a great idea...

ok awsome so how do you sudgest the wireing be like
like where should each of thes compontes go?

Try breadboarding something like this:


ok that actually looks much simpler than what i had anyway