Superfuzz/Ibanez Standard Fuzz LED popping?

[skrunk]

has anyone ever built a Superfuzz or Standard Fuzz clone with an LED that doesn't pop?
I've built a few on vero and always have an LED pop.
I've tried the solutions on AMZ but no luck.
it's definitely the LED as there's no pop when I disconnect it.

I've no issues with popping with any other pedal, I use the GGG input-ground switching, pulldowns on the input and output, but can't get rid.

anyone ever have this issue with this circuit?

[R.G.]

has anyone ever built a Superfuzz or Standard Fuzz clone with an LED that doesn't pop?

Yes.

it's definitely the LED as there's no pop when I disconnect it.

It is most likely layout or wiring/grounding related then.

[skrunk]

ok, thanks RG.

this is the layout I used:



and I use the same wiring scheme as this GGG one:

http://www.generalguitargadgets.com/diagrams/switch_lo_3pdt_ig_dcjack.gif

my grounding is like this:

balance1-->fuzz1-->ground rail on vero
in jack sleeve-->ground rail on vero
ground lug on footswitch-->ground rail on vero
DC jack negative-->out jack sleeve

I'm using new, good quality electros and the wiring is neat and short.
I've tried putting a small 220R resistor in line with the input and between the DC jack and the 9v rail on the board, but no luck.
there's no difference whether I use a battery or 9v power supply.
it's so frustrating.

[R.G.]

I suspect that what is causing your frustration is the parts you can't see - all the wires are really just low-value resistors, not short circuits. When the LED is turned on, it suddenly pulls a current. If that current goes through a wire that's shared with the input, then the voltage that the current causes is seen by the input as a signal, and amplified.

There are two ways to keep this from causing noise. One is to keep the current from the LED out of the signal ground wires, the other is to slow down the suddenness of the current change.

You might try something like this:


Notice that the LED current comes out of the power supply on its own wire, and returns to the power supply negative on its own wire. That way, the LED current can't cause a voltage shift. Well, at least on the DC adapter. The input jack switching all the current to the pedal may still cause problems in some setups.

The higher the gain, the more problems unwanted ground currents cause.

There may be other causes, but this is a very common one. Let me know how it works.

[Kesh]

Sorting out grounding is the sophisticated way, but for a crude solution just go resistor->cap to ground->resistor->LED

[skrunk]

thanks fellas,
RG, I tried your method but it still pops.
Kesh, no luck either,mif I'm even doing it right.

9v to resistor, to cap to ground, then another resistor connected to the first one, to led?

[R.G.]

It's always possible that there's some other problem, too.

Try this: double or triple the resistance in series with the LED. Does the popping get smaller?