switch still poping.....

marrstians · February 09, 2004, 03:07:54 PM

i built the mosfet boost from amz and the switch pops every time i switch it... i've put 1 meg pulldown resistors on the input and output but stil pops...!!! what's the deal? i'm using the tptt switches from aron and i haven't had any trouble with them before.............. stumped...

smoguzbenjamin · February 09, 2004, 03:21:40 PM

I suppose that's a 3PDT switch

Are you sure you're not switching the power? Also, have you got a 1M pulldown resistor at the output cap? That might be screwing with impedances... Try lowering it to 100k if you've got a resistor at the front of the circuit to even out the impedance.

marrstians · February 09, 2004, 03:36:54 PM

do you mean if i have a pull down resistor in the front? i thought that you need one on the input and the output to be the same, no? should i take the second pulldown resistor off or lower the value?

smoguzbenjamin · February 09, 2004, 03:45:07 PM

It all depends on the size of your caps really. Large caps = smaller pulldown resistor. Does the switch pop whenever, or only when you switch it quickly?

The second pulldown resistor might be affecting the output impedance, but if it sounds good and the signal isn't loading down too much (this means lower volume and tone sucking) it isn't a problem, and on impedance issues you can leave it there.

puretube · February 09, 2004, 04:31:09 PM

do you have the resistors on that side of the switch, which looks to the jacks, or on that side which looks to the circuit (regarding the switch)?
The latter is the right side.
(don`t need to be the same value, 4.7M will work, also).

aron · February 09, 2004, 04:49:52 PM

Take a meter and measure for DC on the input and output of the pedal when engaged (i.e. effect is on). If you are getting DC on the output or input, then either your input or output capacitor is bad, or you have a wiring problem.

marrstians · February 09, 2004, 06:33:34 PM

i have the pull down resistors on the circuit it self... no impedience problems... i'll check for the dc thing and see if that leads anywhere...

marrstians · February 09, 2004, 10:36:18 PM

no dc ... what next?

downweverything · February 10, 2004, 03:30:12 AM

how much current do you have running through your led? mine pops when i use a lot of current through the led (about 5mA or more) with or without the pulldown resistors, i just used an ultra bright led with a 10k resistor and now the pop is gone.

puretube · February 10, 2004, 03:36:17 AM

aah, in that case it would not be a question of the switch popping,
but the surge of sudden increased current consumption
(decoupling matter..).

downweverything · February 10, 2004, 03:54:28 AM

yup, that was the case for me

marrstians · February 10, 2004, 11:19:09 AM

i found it.... i guess my mosfet was overbiased... i'm not sure why that made a difference but it did... any explinations?

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switch still poping.....