How to tell which diodes are which

Discussion in 'Effects [BG]' started by russpurdy, Mar 10, 2014.


  1. russpurdy

    russpurdy Supporting Member

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    Apr 16, 2013
    So I want to do some simple pedal modding (diode swapping) in my big muff. My knowledge of pedals is missing pockets here and there. I know where to put everything and to go anode to cathode etc but I have a few diodes kicking around and can't figure out if they are germanium or silicon. From my research silicon can be either glass or germanium correct? Could I use the small place platic style diodes and would they sound much different than glass ones? Thanks!
  2. rratajski

    rratajski

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    Builder for FUZZROCIOUS PEDALS
    Pics are helpful ;)
  3. russpurdy

    russpurdy Supporting Member

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    Apr 16, 2013
    Pics and I and this site don't get along but I'll try my best
  4. russpurdy

    russpurdy Supporting Member

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    Apr 16, 2013
    While I work on photos how about a description...

    Larger than (what I believe to be silicon diodes that are alreay in the pedal). Looks like it has some kind of filament attached to a plate inside. Clear glass, one green stripe.

    I also have some black plastic diodes with a grey stripe. Am I correct in thinking these are silicon and is it likely they will sound much different than the glass silicon diodes already installed?

    Thanks for humouring my ignorance!
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  6. russpurdy

    russpurdy Supporting Member

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  7. rratajski

    rratajski

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    Builder for FUZZROCIOUS PEDALS
    Any numbers on the sides?
    Sounds like germanium (large glass) and 1n4001 silicon. By the look of the photo, that is germanium.
  8. johnk_10

    johnk_10 vintage bass nut Supporting Member

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    a clear glass one with a green stripe is definitely germanium.
  9. johnk_10

    johnk_10 vintage bass nut Supporting Member

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    keep in mind that when you replace a silicon diode with a germanium one, the pedal will have a lot less output due to the germaniums having a much lower forward voltage.
  10. russpurdy

    russpurdy Supporting Member

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    Apr 16, 2013
    Thanks guys. I have a few follow up questions...

    I put the diodes in and im digging the germanium diodes for clipping but there is a monster volume drop as you said and its a tad bass heavy. What would be the best way to solve this? I was thinking...



    1) replace one germanium diode with a red led or possible silicon diode



    2) try out asymmetrical clipping. Am I correct that in this case I would need a third germanium diode and have two going one way and the third going the opposite way? Is it possible to use silicon for the third diode to get more volume and bite?



    Thanks!
  11. johnk_10

    johnk_10 vintage bass nut Supporting Member

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    I usually use two ge diodes in series to replace a single silicon one so the volume drop isn't so drastic. you can also mix and match, germaniums with silcon or leds for asymmetrical clipping.
    BTW, mosfet transistors can also be used as clippers (as used in the fulltone OCD).
  12. russpurdy

    russpurdy Supporting Member

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    Apr 16, 2013
    Would a silicon diode take over the tone if run asymmetrically with two germanium or would I get a true hybrid type of sound? Thanks!
  13. johnk_10

    johnk_10 vintage bass nut Supporting Member

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    John K Custom Basses
    generally speaking, silicons like a 1N400X or a 1N4148 have a forward voltage of about .7V. germaniums are in the .245V-.350V range, so two germaniums are about the same as one silicon and will clip at around the same voltage. germaniums have a softer 'knee' clipping characteristic so it'll still be asymmetrical but not as asymm as using one of each.

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