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Simple analog voice distortion circuit

  1. Aug 2, 2013 #1
    Hi, i'm trying to build a simple analog voice distortion circuit, without any ICs if it's possible. It can get pretty hard to hunt down a specific IC around here.

    Anyhow, my idea was to get a mic, a speaker, a few oscillators, analog multipliers and RLC filters to build a real time distortion (it will be a portable device, so it will be DC powered). I know it's probably too much to ask, but the original idea was that the distortion came out as kinda robotic, but it's not a must, any cool distortion will do it.

    Can anyone point me in the right direction? I'm sort of the electrical engineering student with a lot of theoretical knowledge and little experience, so spare no explanations. Maybe just tell me a good waveform to multiply the input with and i'll search how to do it.. any help is appreciated. Pretty much everything I found involved an IC, so if I there's any chance I could avoid that, that'd be great.

  2. jcsd
  3. Aug 2, 2013 #2


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  4. Aug 2, 2013 #3
    Wow that was fast and very helpful, thank you very much nsaspook! I'll post how this turns out in case anyone is interested.
  5. Aug 2, 2013 #4


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    I hope you make something cool. With the proper circuits to generate pseudorandom mixer carriers you can even make a pretty good voice scrambler device that sounds similar to this:
    Voice Inversion:
    Simple inversion scrambler
    Last edited: Aug 2, 2013
  6. Aug 11, 2013 #5
    Hi again! So I built the modulator and it works great... but there's something weird about it. I'm using my PC's stereo output to feed both the audio signal and the 30Hz carrier wave. The audio on the left channel and the 30Hz wave on the right channel.

    I'm generating the signals in Audacity, but here's the weird thing: when I do a 100% separation of the tracks between channels, I can't hear almost anything. When I let a little bit of the carrier onto the other channel, it sounds a lot like it should... like youtube videos demonstrating the circuit. If I just go 50% both signals, i.e. not splitting the tracks at all between the channels, as if it were mono output I guess, it sounds perfect...

    Why does this happen? It's really weird. I tried to contact the guy who made that tutorial but didn't find any contact info.

    Thanks in advance
  7. Aug 12, 2013 #6


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    As a wild guess, maybe you have the center tapped windings connected incorrectly.
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