Switching POP in a passive stompbox

[wcampagner]

Hello,

I'm building a passive stompbox... it is basically a volume control... just a potentiometer and a capacitor (simulating the volume pot of the guitar).

The problem is that i'm having troubles with switching POP... i'm using a DPDT...

So i think there is no DC problems... but i also put 1M ohm resistors on INPUT and OUTPUT... but the POP is still there...

I'm not using LED's too... so there is no problem... i'm planning to use LED's but i'm trying first to solve this POP problems...

I really don't know what's wrong... maybe the quality of the DPDT switch?? Does anyone experience POP's because bad switch quality?? What could be the problem??

One thing i noticed is that the POP's change from amp to amp... i've tested the stompbox in a Peeavey amp and the POP is almost unnoticed... i could live with that... but i also tested in a Fender amp and the POP is much louder than the Peavey amp... and as volume goes up... the POP gets louder.

Are the true-bypass stompbox really POP free?? Or they have some POP switching?? I have a sansamp GT-2 with is electronic bypass and it is very silent... i've never tested any true-bypass stompbox so i wanted to compare both switching methods...

Thanks,
Wagner.

[wcampagner]

anybody?? please??

[LyleCaldwell]

How do you have the switch wired?

[petemoore]

  Caps have the 'cap'acity to hold voltage, how's the cap used here/wired?

[wcampagner]

Thanks for the answer...

The circuit i'm building is very simple...

The schematic is here:



That's the way the DPDT is wired... but if i can manage to solve the switching POP i want to change the wiring to make a Millenium Bypass and insert a LED.

Thanks in advance for helping.
Wagner.

[R.G.]

From your description, it sounds to me like your amp or guitar has a bit of DC on its input/output as the case may be.

Pop results from an instantaneous change in DC level. The pot/capcitor is pretty sure to be at 0V when it 's switched in, so the DC must be in the guitar or amp.

One possible palliative for the symptom is to hook a 2.2M, 3.3M or 4.7M resistor across both the input and output jacks. That might help.

[LyleCaldwell]

That wiring for the DPDT can also produce pops.

This is better practice (grounds out the circuit when bypassed):

[uan]

any diagram for better 3dpt wiring? i'm also having the same problem with my 3DPT..

[syndromet]

any diagram for better 3dpt wiring? i'm also having the same problem with my 3DPT..

Just wire up the 2 poles that has to do with effect switching the way shown above. A 2pdt is simply two switches with one button, and a 3pdt is 3 switches with one button.
Read This, and you'll understand how they work. Using switches becomes very much simpler when you understand them, and will make everything easier on you.
Take care 

[Cliff Schecht]

The high value resistors don't fix your problem?

[wcampagner]

Hello,

Thanks for all the posts...

R.G.: i tried the 3M3 resistor across input and output, but the POP continues...

LyleCaldwell: i also tried your wiring DPDT diagram, but didn't solve the problem too...

I don't know... i'm thinking it can be a poor quality switch... i'm using a DPDT X-Wing... but i don't what's the manufacturer.
Do you thing poor quality switch can also cause "POPS"?

The problem is that i've never seen a true-bypass pedal in action... maybe this POP can't e fixed... i have only a sansamp GT-2 and the bypass is very... very silent... so i think i'll be changing to electronic bypass.

Thanks,
Wagner.

[R.G.]

Simply going to another "solution" won't tell you much, even if it works.

Did you happen to use your meter to see if there was DC on the output of your guitar or amp?

There is no reason that a stomp switch can't be almost silent, as many of us have found. It takes some work to make an electronic switch quiet.