Poppings

[petemoore]

Nice new...3PDT, and it still pops...the DIST +...
 Are 1m5 too big to make the differenc e? That's the size I used for pulldown resistors...pops equally [pretyy loud] in either direction: on //off, Off // On

[Paul Marossy]

Try 1M or maybe 820K. I think the 1.5M may be a little too big.

[will]

Hi Pete,

Nice new...3PDT, and it still pops...the DIST +...
 Are 1m5 too big to make the differenc e? That's the size I used for pulldown resistors...pops equally [pretyy loud] in either direction: on //off, Off // On

Really sounds like there is some DC offset happening here. Could it be a leaky, bypassed or missing coupling cap, or a solder bridge, or cold solder joint preventing the pull down resistor from working? Or incorrectly wired switch or incorrectly placed pull down resistor. Or perhaps when putting the circuit into an enclosure some undesired connection is happening. A 1M5 resistor should not be too big to pull down the voltage on the end of a coupling cap.

I’m sure it’s something simple, once you find it. Good luck!

Regards,
Will

[Paul Marossy]

Maybe, maybe not. I have had at least one build where I had to put a 1M pulldown resistor on the input and the output before it stopped popping.

[petemoore]

Pretty certain the cap was the fading problem I was haveing.
Had to have been...Circuit itself works great.
 Maybe I'm just over due for cap problems...no biggie..I'll slip some new ones in the sockets...

[Jered]

If your Dist + is going IN or OUT of another DIY pedal, check those also. It could be a combination of the two causing the popping. Is the switch new?
 Jered

[jimmy]

sorry to hijack your thread, but is it POSSIBLE to have too BIG a pulldown resistor?

cheers
Jim

[Peter Snowberg]

sorry to hijack your thread, but is it POSSIBLE to have too BIG a pulldown resistor?
cheers
Jim

As the resistor gets larger.... so does the thermal noise across it. It's a tradeoff between lowering the impedance and raising the noise floor.

Take care,
-Peter

[Boofhead]

You should be able to use resistors in the 2.2M to 4.7M.

I suspect the pop problem is possible else where - perhaps inherent in the switch itself, lack of a similar pull-down resistor (100k or so)  on the output, bad cap, input output caps which are too large.  Yet another issue is oscillation in the offstate.

If you are using an LED circuit then that's a whole other area for possible noise causes - the easiest way to determine if the LED is the cause is to disconnect the LED circuit.

Thermal noise isn't a problem when the effect is on since the thermal noise is shunted out by the input source.   Stray noise pick-up can be an issue on the effect on the off-state but this is usuall low with reasonably layout and case shielding.

[petemoore]

The indicator LED  IS running down' the middle of the 3PDT...
 I have you guys to...thanks again !!!
 I have plenty of things to look at and chew on for a time now !!!
 I'll see if I come up with anything that brings 'it down!!!

[Paul Marossy]

If the pulldown resistors do not help, try using a grounded circuit input scheme. Your circuit might be oscillating when bypassed and then you switch the circuit in, and POP!

I had a similar problem on my Shaka Tube re-build. Although the pull down resistors took care of the pop, they didn't help when the circuit was oscillating while bypassed. Enter the ground circuit input bypass switching...