Pop on secondary switch

[DeusM]

Hey guys. So I made a BMP witch a switch for activating a mid control or to remove that control and remobe the mid scoop totally. It also has an LED that turns on when the mid scoop (body) control is of. There is a loud pop when I activate the switch. Not when I turn the effect on. Notice that when the effect in turn off and both LEDs are on, the second one takes some time to be completely off but when I activate or deactivate it by itself it turns off immediately. It's too bright but I don't want to keep messing around with it because the board is pretty bad by now. I was thinking about a pull down resistor at the end of the circuit or increasing the value of the resistor of the LED R24. The other resistor and capacitor are to avoid the pop like the page AMZ says. It worked fine for me on a previous build that had not another LED.



Heres a picture of the pedal. I made it using the etching method and I'm pretty happy despite al the trouble 

[Mark Hammer]

The other method is to simply never flick that switch when the effect is on, keeping use of that switch to when in bypass mode.

[DeusM]

The other method is to simply never flick that switch when the effect is on, keeping use of that switch to when in bypass mode.

Theat kills the whole purpose of the swtich. Not a great solution my friend.

[amz-fx]

The wire that goes from the center lug of the switch to the end of C10 has a DC bias on it. You can trace the DC path through the tone pot, R18 and R17 to the +9v.

When the Body control is on, the resistances of the Body control are pulling the voltage down some. When the switch is open, the end of C10/wire is pulled up to 4 or 5v. This makes a pop.

You can add a 1M to 10M resistor to ground from the junction of C10 and the wire going to the center of the switch. I would start with 10M and see if it helps, and if it does, you can reduce it to 2M2 or even 1M as required. (or lower) It may always pop but this should pad it down some.

regards, Jack

[DeusM]

The wire that goes from the center lug of the switch to the end of C10 has a DC bias on it. You can trace the DC path through the tone pot, R18 and R17 to the +9v.

When the Body control is on, the resistances of the Body control are pulling the voltage down some. When the switch is open, the end of C10/wire is pulled up to 4 or 5v. This makes a pop.

You can add a 1M to 10M resistor to ground from the junction of C10 and the wire going to the center of the switch. I would start with 10M and see if it helps, and if it does, you can reduce it to 2M2 or even 1M as required. (or lower) It may always pop but this should pad it down some.

regards, Jack

I only had 10M so that's what I used. There is still com pop. Not so loud now. But now the first LED takes a litle time to turn off when only it is on, but it inmediatly turns of when both LEDs are activated.

[PRR]

Just put in the missing cap.

[DeusM]

Just put in the missing cap.

I'll try that in my next build!
Thanks

[Rob Strand]

I'll try that in my next build!

An easier retrofit is to put the cap in series with R18.

[DeusM]

Just put in the missing cap.

Won't that affect the tone?

[DeusM]

Ok. It works great now! No poping at all! You guys are great! But I still have the doubt if it changes the tone. Also the 2nd is slighly on when I tur the efect off.

[antonis]

Leaky C15 on master switch..??

Need for coffee...