Popping noise when switching

Matt Martin · Post by **Matt Martin** » 20 Sep 2003 1:21 pm

What causes the pop noise when I stomp the switch on my Small Stone?? I had to resolder a battery termial back on and maybe something else got too hot?? Could it be the out jack, as it's affecting the other switch too. Anyone have any experiance with this??

Matt Martin · Post by **Matt Martin** » 21 Sep 2003 3:29 am

Leon Roberts · Post by **Leon Roberts** » 24 Sep 2003 5:52 am

Matt, I have experienced the popping sounds back when I used the small pedal effects. The worst offender was the “PEI Junior” that simulated an organ tone. I solved the problem by building a bypass box designed by Fred Layman. All the pertinent information for the bypass box was in one of Tom Bradshaw’s Steel Guitarist Magazines. I don’t really know what causes the pop but I know it’s there. I now use a Boss SE-50 for all my effects and no pops what-so-ever. This might not help but at least you will know you are not the only one that has had the problem. I think some of the newer pedals have switching systems that eliminate this popping sound.
Leon

Paul Osbty · Post by **Paul Osbty** » 25 Sep 2003 12:58 am

On a lot of stomps, your signal is going through the switch. An older switch can get mechanically "clumsy" after a while. It does do the job, just not as cleanly.

Try replacing the switch. Make sure it is identical in every way, especially, the Push On/Push Off action.

Terry Downs · Post by **Terry Downs** » 25 Sep 2003 6:02 pm

Many of the old pedals that use a machanical switch to insert/bypass the effect switched to the output coupling capacitor of the effect with no charging resistor. If a transistor or opamp output amplifier has half of the voltage supply on it, and the DC blocking capacitor is open, it will be discharged. Once switched into the circuit, the DC bias from the final amp is switched into the output jack. This makes a big pop sound. You can eliminate this by putting a ~100K resistor from the output of the DC blocking capacitor to ground. This keeps the capacitor charged and the output near ground. That way, when you switch it in, there is no big transient pop.

Here is a schematic for the small stone. It has a 470K charging resistor on its output. Make sure it is connected.

http://www.lynx.bc.ca/~jc/moddedSmlStnSchm.gif

Check it and see.<FONT SIZE=1 COLOR="#8e236b"><p align=CENTER>[This message was edited by Terry Downs on 25 September 2003 at 07:03 PM.]</p></FONT>