crybaby GCB95 eccessive loud pop when powered in

[Mantra]

Hi to all
i'm new ,english is not my native language , i will do my best

well i have a problem with a crybaby GCB95 mod (the modification is true bypass and led ) , now i have removed the led and rewiring

the problem is a loud pop when I tun on the fist time only after I powered with a psu or battery.
it's weird because i have used the battery and a small amp using the batteries too, in short without any psu ,all with batteries , and i have tested with several different guitars

to be clear , guitars -> wah with battery -> black star with battery , and i have tried different cables too , i did it to avoid electricity issues

it's very weird because:
1) I power it with a psu or battery , i turn on with the footswitch and i got this loud pop , i turn off the wah  and turn in the wah again the pop does disapear
2) I power off and power in , and the first turn on generate this pop

in short i got this loud pop only when i turn in the first time after powered in with a psu or battery , if i disconneted the power and re-enable the power i got this pop again only the first turn in

i have others pedal but they don't make such loud pop

I have used a small amp 3wat , but think about with a marshall tube amp 200W and a cabinet 4x12 400W
thanks
pop sounds
https://soundcloud.com/user-935315180/sound2?si=545c1293315e4c20aaab462bab345784
https://soundcloud.com/user-935315180/sound?si=0af2733b47ba482aba271589b5bf0405

images sorry , i could upload maybe they are too big , my apologies

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https://ibb.co/pLkXQy3
https://ibb.co/5vwhfYt
https://ibb.co/z625SFB
https://ibb.co/CmSsqGj

[fowl]

Wire your foot switch so that the circuit input is grounded in bypass mode.

[Mantra]

Wire your foot switch so that the circuit input is grounded in bypass mode.

hi
may i know what do you mean (it's wired like the standard way with a switch with 9 pins)?
might you please explain ?

Appreciate your help , sadly my english is poor

[idy]

from "stinkfoot" site. You can google "3pdt bypass grounded input" for more pics of the same thing.


Note that the three lower left pins (#2,3,6) could all be soldered together. In any case the ground for the LED goes to circuit in when the circuit is bypassed

[idy]

But you also should check the amp...plug a cable in, power on (but volume down!) and see if there is any voltage on the other end of the cable. That makes pedals pop too. Called "pedal ventriloquism."

[anotherjim]

I don't know why R2 is omitted, I would fit 10M there if you don't want to change the switch wiring.
While you have it opened up, do check the quality of the solder joints on the connector pins, particularly the DC power socket.

[antonis]

ΙΜΗΟ, a 10nF (non-electrolytic) cap should be tooooo leaky for popping..

[Rob Strand]

Wire your foot switch so that the circuit input is grounded in bypass mode.

hi
may i know what do you mean (it's wired like the standard way with a switch with 9 pins)?
might you please explain ?

Appreciate your help , sadly my english is poor

[Mantra]

Hi
first I want to thank all of you
second it's the first time I got such problem , I mean the loud pop does happen only after powered in (with psu andor battery) and turned on the wah (only the first time) ,if i turn off/on many times i don't get any loud pop.
If I unplug the psu or the battery , I get again the same loud pop only the first time I turn on the wha

to avoid it , I use a volume pedal , powered on my psu , turn on the wah and turn off again the wha  , and i don't touch anymore the psu

have you seen such issue ?

I re-wired without led yesterday again , checked all solder joints , and i use an electronic cleaner spray for each solder joints , they look clean and good

no luck

ΙΜΗΟ, a 10nF (non-electrolytic) cap should be tooooo leaky for popping..

I don't know why R2 is omitted, I would fit 10M there if you don't want to change the switch wiring.
While you have it opened up, do check the quality of the solder joints on the connector pins, particularly the DC power socket.

I re-wired without led , 1-2 bridge ,3-8 bridge  , green -> 8  ,blues -> 9  , magenta  -> 6   , cap to 5

the next steps will be replace the cap  and the r2 resistor , i haven't never replaced the r2 restistor , it did come with it , gold red black , 12Ohm

i have upload new pictures (sorry i don't know how upload
https://ibb.co/6mYRZDW
https://ibb.co/TL9V2hZ
https://ibb.co/hgbH5g0
https://ibb.co/pjTKsHT
https://ibb.co/Js92Hvb

[antonis]

gold red black , 12Ohm

You probably mean BROWN, Red, Black (12R)..
Gold colour band isn't used for digit value but for tolerance (5%) only..
(and for band multiplier for values lower than 1 Ohm..)

P.S.
12 Ohms value for R2 equals to dead silent pedal..
(probaly R2 is of some other much higher value..)

[Mantra]

gold red black , 12Ohm

You probably mean BROWN, Red, Black (12R)..
Gold colour band isn't used for digit value but for tolerance (5%) only..
(and for band multiplier for values lower than 1 Ohm..)

P.S.
12 Ohms value for R2 equals to dead silent pedal..
(probaly R2 is of some other much higher value..)

Hi
sorry for my error
R2 resistor is gold -red - black -brown -> so  it's brown - black -red = 1K   
i could try 1M as suggested
thanks

[anotherjim]

I don't think your PCB as the parts numbered the same as the schematic I posted. I think it's a redrawn one and the CAD program used has given its own automatic numbering.
Other drawings I found don't show any antipop "R2" resistor. To fit one you may need to trace the input wire from the footswitch back to the PCB where it connects to the 10nF cap into the first transistor stage and find a 0v for the other end of the resistor.

[ronh]

I have this problem with my cry-baby.  I have gone through the pedal and cant find the cause.   My fluke meter does not read any voltage around the switch or jacks.  I can say its not the switch, pot, coupling caps, filter cap. I tried the grounded input bypass switch circuit.  Did not fix.  Re-soldered any joint that looked iffy. If anyone comes up a solution, I will say thanks right now.
I think of this as a feature - pre solo attention getter.

[Mantra]

I have this problem with my cry-baby.  I have gone through the pedal and cant find the cause.   My fluke meter does not read any voltage around the switch or jacks.  I can say its not the switch, pot, coupling caps, filter cap. I tried the grounded input bypass switch circuit.  Did not fix.  Re-soldered any joint that looked iffy. If anyone comes up a solution, I will say thanks right now.
I think of this as a feature - pre solo attention getter.

Hi Ronh
really ? have you the same problem?
I get this pop up only the first time i turn on the wah , after I power in with psu or battery. I don't get any pops the second time i turn it on  , to get again the pop i have to power off , wait few seconds and power in again
have you installed a 9 pin or 6 pin foot switch ?
thanks

[antonis]

I get this pop up only the first time i turn on the wah , after I power in with psu or battery.

Replace reservoir electrolytic cap (C8 on anotherjim's posted schematic)..

[anotherjim]

You can get misbehaving ceramic caps in those Dunlop products - mechanical shock from operating the footswitch can bring it on. These are the little tubular mustard coloured ones.
A bad DC power jack can cause trouble. The charge stored in the reservoir cap "C8" can hide short period disconnections sometimes. Again, mechanical shock will bring one on.

[PRR]

..pop up only the first time i turn on the wah , after I power in with psu or battery. I don't get any pops the second time....

So power-up before the crowd arrives.

My old PA system used to make a horrible racket at power-up, so I tried to get it all going before the doors opened. Or while the crowd was loud.

[ronh]

Mantra, my switch is a 6 pin, did not fix.  As for C8 or power supply filter cap, removed, then replaced did not fix.  The noise from a cap could be the problem.  But which one?  The pop is really loud, so there must be some gain attached to it, No?  From what happens I think its a dc charge that gets discharged.
Power up, switch to effect mode  pop.  Switch back and forth no pop.  Wait a couple of minutes, switch to effect on and pop.

[anotherjim]

Dunlop adding the input buffer probably makes this worse. The higher resistance in the buffer input bias slows the input cap charge rate making the pop longer and more obvious.

I suggest trying the original simple bypass that leaves the input always connected. That will prove if it is the input cap popping or, as I tried to point earlier, the pop is something else coinciding with the mechanical shock from operating the switch.

[antonis]

The higher resistance in the buffer input bias slows the input cap charge rate making the pop longer and more obvious.

Sorry but I don't get you, Jim..

Buffers exhibit high input impedance and LOW output one..
The later is seen by the input cap so it is charged/disgharged quicker..
(actually, input cap side is more effectively grounded than in case of high value anti-pop resistor..)