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Thread: Wah - troubleshooting

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    Wah - troubleshooting

    Today I recall events that involved fixing a wah pedal. I'm wondering if there's a basic procedure to follow to fix one, e.g. Crybaby type and most common issues.

    With an Ω meter I tested the pot - OK
    Replaced upgrading the transistors
    Measured sweep of pot - OK
    Swapped out two electrolytic caps as they seemed in the vicinity of problem - same/OK

    So what next? I'm sure there's a lengthy topic on this but it doesn't show up on a search.

    I did find:
    Measure across the inductor's 33K Ω The inductor has a low DC resistance--normally under 75 ohms. The 33k resistor is in parallel with the inductor, so the in-circuit resistance measured across it should be lower than the inductor's resistance. If you measure a high resistance here (around 100 ohms) then the inductor is probably open.

    1.Positive (Red) at base and negative (Black) at emitter should give you a measurement of 0,45V to 0,75 V
    2.Positive (Red) at base and negative (Black) at collector should give you a measurement of 0,45V to 0,75 V
    3.Negative (Black) at base and positive (Red) at emitter should give you a measurement of 0 Volts
    4.Negative (Black) at base and positive (Red) at collector should give you a measurement of 0 Volts.
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    Last edited by Guitarist; 01-31-2019 at 03:48 AM.

  2. #2
    Don't forget the joker g1's Avatar
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    What's the problem? Is the switch working?

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    Just because they don't have tubes doesn't mean they don't have feelings! - glebert

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    Yes switch passes clean.
    LEDs work but only unchanging hum is heard during sweep.

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    Last edited by Guitarist; 01-31-2019 at 04:18 AM.

  4. #4
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    And the model is Snarling Dogs Whine-O ?

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    Just because they don't have tubes doesn't mean they don't have feelings! - glebert

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    Yes, today it is. A rather cool pedal really but too big for me. It's a tad confusing...

    thanks.

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  6. #6
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    I don't think that schematic will get you anywhere.

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