1M pulldown resistors and still popping...

[Xavier]

Two of my latest builds still pop when engaged. I found out yesterday at the rehearsal room.

Should I just raise the resistor values? The AMZ Mosfet booster and the OD1 have resistors only at the input.

[smccusker]

try putting one just before the output as well.

[Jaicen_solo]

You may also suspect the switches. Certain switches i've had have mechanical switching noise that cannot be gotten around with pulldown resistors. I used to use the large black ones with the MM logos, but I now use those little blue RS swithces similar to the common 3PDT.
That said, there is some value in having an output pull down too. AMZ Mos-boost should have a 100K resistor to gnd after the final cap. That cap is probably causing the problems in that particular circuit.

[Xavier]

You may also suspect the switches. Certain switches i've had have mechanical switching noise that cannot be gotten around with pulldown resistors. I used to use the large black ones with the MM logos, but I now use those little blue RS swithces similar to the common 3PDT.
That said, there is some value in having an output pull down too. AMZ Mos-boost should have a 100K resistor to gnd after the final cap. That cap is probably causing the problems in that particular circuit.

Yep, the vero layout I used for the AMZ boost doesn't have the 100k resistor, thanks.

I use german made Knitter switches. They are smoother than the typical blue taiwanese ones. The mechanical "click" as you step on it is noticeably quieter.

[Mark Hammer]

Two things:

1) Whenever you have a cap with a free end just hanging there, you will get a pop, and the larger the cap value the bigger the pop.  That "free end" could be at the input, at the output, on a settings switch or wherever.  Caps always need a continuous way to discharge, or else when you suddenly provide them with a discharge path they will dump their stored charge in a largish burst.  Benjamin Franklin, in the days before DMM's, would assess the charge stored in his glass "Leyden jars" (one of the earliest capacitors studied) by, um, zapping chickens, believe it or not.  The impact of a .01uf cap at a pedal input is obviously not the same as a large foil-lined jar when it comes to storing charge, but the principle is the same - a cap will store charge to its maximum capacity unless you provide it a path to discharge continuously; if the path is provided after some interrupted period, all that charge will want to come out at once.  The traditional high-ish value resistors at the input provide a means for those caps to constantly drain, without loading down the input very much when you connect the guitar to the actual input of the circuit.

You will note that companies like Boss, et al, which use "always on" buffers and use FETs for switching/bypass, rarely, if ever, have an input resistor.  Your guitar goes straight to a "hanging end" cap.  Why?  Because the switching is handled elsewhere in the circuit and not at the input.  There will be a little "thump" when you plug in but no popping after that no matter how often you bypass switch.  I'm not suggesting this is the way to go.  Rather, if your goal is ever to clone one of these normally FET-switched effects, but house it in a box with a DPDT or 3PDT stompswitch instead of FET-switching, you will need to add that bleed resistor to the input of the circuit.  They leave it off because they can, given their switching scheme, but a mechanical whole-circuit bypass can not afford to.

2)  If you pop the hood of a stomp switch (which you can also do wrong, but normally it can be done in a nondestructive and reversible way), youwill see that the mechanism is pretty simple.  What you might also see are corroded or tarnished contacts.  Don't be shy to clean them up or add some "miracle fluid" to improve the contacts.  A well-made stompswitch should probably behave reliably and not produce audible clicks, but cheap to moderate quality switches can also be improved beyond where they are now by some "internal housecleaning".

[Xavier]

two things:

1) Whenever you have a cap with a free end just hanging there, you will get a pop, and the large the cap value the bigger the pop.  That "free end" could be at the input, at the output, on a settings switch or wherever.  Caps always need a continuous way to discharge, or else when you suddenly provide them with a discharge path they will dump their store charge in a largish burst.  Benjamin Franklin, in the days before DMM's, would assess the charge stored in his glass "Leyden jars" (one of the earliest capacitors studied) by, um, zapping chickens, believe it or not.  The impact of a .01uf cap at a pedal input is obviously not the same as a large foil-lined jar when it comes to storing charge, but the principle is the same - a cap will store charge to its maximum capacity unless you provide it a path to discharge continuously; if the path is provided after some interrupted period, all that charge will want to come out at once.  The traditional high-ish value resistors at the input provide a means for those caps to constantly drain, withuot loading down the input very much when you connect the guitar to the actual input of the circuit.

You will note that companies like Boss, et al, which use "always on" buffers and use FETs for switching/bypass, rarely, if ever, have an input resistor.  Your guitar goes straight to a "hanging end" cap.  Why?  Because the switching is handled elsewhere in the circuit and not at the input.  There will be a little "thump" when you plug in but no popoin after that no matter how often you bypass switch.  I'm not suggesting this is the way to go.  Rather, if your goal is ever to clone one of these normally FET-switched effects, but house it in a box with a DPDT or 3PDT stompswitch instead of FET-switching, you will need to add that bleed resistor to the input of the circuit.

2)  If you pop the hood of a stomp switch (which you can also do wrong, but normally it can be done in a nondestructive and reversible way), youwill see that the mechanism is pretty simple.  What you might also see are corroded or tarnished contacts.  Don't be shy to clean them up or add some "miracle fluid" to improve the contacts.  A well-made stompswitch should probably behave reliably and not produce audible clicks, but cheap to moderate quality switches can also be improved beyond where they are now by some "internal housecleaning".

I'll try to assimilate your *huge* explanation . Totally makes sense...Thanks

[Jaicen_solo]

Actually, by Mr Hammers' standards, that was a relatively concise answer!

[bioroids]

I thought that the pop was due to the capacitor leaking, not exactly related to the stored charge. It does make sense, however, but now I'm confused

Luck

Miguel