Help with Guitar Distortion Pedal Schematic

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Discussion Overview

The discussion revolves around a schematic for a guitar distortion pedal, focusing on the behavior of a capacitor and switch within the circuit. Participants explore the implications of a potential short circuit and the configuration of diodes in relation to signal clipping.

Discussion Character

  • Technical explanation
  • Debate/contested
  • Mathematical reasoning

Main Points Raised

  • One participant questions whether a short circuit exists following a 220uF capacitor in the schematic, suggesting that current might bypass this section due to the presence of diodes.
  • Another participant argues that for a short circuit to occur, the wire connected to the capacitor would need to connect to ground, which they assert is not the case in the current configuration.
  • A later reply clarifies that a short circuit could only happen when the switch is closed, indicating that the concern is about signal clipping when the switch is engaged.
  • One participant proposes a circuit modification that includes the diodes, suggesting that this would affect the output voltage and clipping characteristics of the pedal.

Areas of Agreement / Disagreement

Participants exhibit disagreement regarding the existence of a short circuit in the circuit design. While some express concern about the implications of the capacitor and switch configuration, others clarify the conditions under which a short would occur, indicating that the discussion remains unresolved.

Contextual Notes

There are unresolved assumptions regarding the specific connections in the schematic and the behavior of the circuit under different switch positions. The discussion also includes dependencies on the definitions of short circuits and clipping behavior.

Who May Find This Useful

Individuals interested in guitar pedal design, electronics enthusiasts, and those seeking to understand circuit behavior related to audio processing may find this discussion relevant.

MG-Zero
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Hey, I've been working on putting this schematic together (Not my design, got it off of instructibles.)

The-schematic.jpg


It's a distortion pedal for a guitar, at this point I have an amplified clean sound coming through, so I know the audio amp is working. My question is, since there's a short circuit following the 220uF capacitor, won't all of the current just bypass that section with the diodes? If so, would it be better to put that part in series with the capacitor and switch?

pinout for the op amp is here
http://www.hobby-hour.com/electronics/lm386-power-audio.php
 
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I don't see any short circuit there.
 
Between the 220uF capacitor and the dpdt switch. Isn't that a short? Or am I just a dumbass and forgetting something? Probably the later, heheh.
 
For there to be a short, the wire to the right of the 220 uF cap would have to connect to ground. This is not the case here, for either position of the dpdt switch.
 
Oh, a short when the switch is closed.
 
For there to be a short, the wire to the right of the 220 uF cap would have to connect to ground. This is not the case here, for either position of the dpdt switch.

I see, so for it to be a short, the diode section (where ground is) and the negative of the cap would have to be connected to the same thing.

Oh, a short when the switch is closed.

Yes, that's what my concern was since if it was a short, none of the signal from the guitar would be clipped.

Thank you for the help, guys.
 
You would have to include the diodes in the circuit like this:

[PLAIN]http://dl.dropbox.com/u/4222062/clipping%20amp.PNG

The output would be about 4 volts p-p and have more clipping on the positive half cycles than the negative half cycles for an input of more than 200 mV p-p assuming a gain of 20 from the 386.

You should see the LED flashing for high inputs.
 
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