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Mini toggle POP sound- which component to use?

Zentner

Zentner

May 5, 2003
1,378
337
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Edmonton, Alberta, Canada
#1
So I've read a few threads on this- some people (sadowsky) are using a capacitor between the switch and ground, everyone else seems to think a resistor will work better.

I've got a Series/Mute/Parallel switch where in the (center) mute position the pickups' signal just goes to ground. Should I just put a resistor between the switch's output and my ground? What value?

Thanks!
 
#2
A capacitor is only going to increase the amount of switch pop. Capacitors store and dissipate energy. Resistors consume it by converting to thermal dissipation.

The resistors should go from common to normally open, and from common to normally closed. You generally want to use a value that is low enough to get rid of the switch pop, but high enough to not have any effect on the circuit. 1M Ohms seems to be a common choice.
 
#3
I'm surprised it'll have an effect on the circuit if it's just taking the pickups's signal, running it through a resistor to ground. The resistor won't be part of the active circuit when not in the mute position, so how will it affect the circuit at all?

What am I missing here?
 
#4
Zentner said:
I'm surprised it'll have an effect on the circuit if it's just taking the pickups's signal, running it through a resistor to ground. The resistor won't be part of the active circuit when not in the mute position, so how will it affect the circuit at all?

What am I missing here?
Click to expand...

How do you have the switch wired? The typical way to do it is to wire a standard series/parallel with a DPDT On/Off/On, so that the center position simply disconnects boths pickups. There are not enough poles to ground both pickups' hot leads.

With standard series/parallel wiring, series puts a resistance between the series link and ground, and between the series link and bridge pickup's input; parallel puts a resistance between the bridge pickup's hot and ground. (Equal to the sum of two resistors' resistances.); and the mute position puts a resistance between the bridge pickup's hot and it's usual input, between the neck pickup's negative phase lead and ground, and between the neck pickup's negative phase lead and the bridge pickup's hot (Equal to the sum of two resistors' resistances.)

In any case, the resistors are there to dissipate the energy when the switch is flipped. In one position, a pair of resistors will be shorted, and in the other, a pair of resistors will decrease the impedance of the path from common to the unused throw of each pole, from infinite, to the value of the resistor. This allows electrons to flow where they aren't supposed to, so the value of the resistors needs to be high enough that it won't be a problem to the circuit.
1M Ohms should be fine.
 
#5
CTWiring.jpg


So, the leftmost switch just takes the signal from the (master) tone pot, in either down or up positions is on, and center it takes the signal and grounds it.
 
#6
Zentner said:
CTWiring.jpg


So, the leftmost switch just takes the signal from the (master) tone pot, in either down or up positions is on, and center it takes the signal and grounds it.
Click to expand...

Ah, I remember this diagram from a thread a few weeks ago.

I'm not sure if I mentioned it before, but swap the output jack's connection to the switch with the tone pot's connection to the switch. The output should see a 0 Ohm shunt to ground when muted, because an infinite output impedance would give you more of an "open cable buzz."
 
#8
Zentner said:
Alright- will I still need a resistor between the switch and ground too?

I'm still not sure how this resistor will affect my circuit if it's not in line when my circuit is active....
Click to expand...

Why would you put a resistor between the switch ands ground? Where would you even put it?

The only time you use resistors is when you have a cap in the signal chain. The cap needs to be bled off, so you use a pull-down resistor.

You should not be getting a pop unless you switch the switch while playing.
 
#9
SGD Lutherie said:
Why would you put a resistor between the switch ands ground? Where would you even put it?

You should not be getting a pop unless you switch the switch while playing.
Click to expand...



Well that is my question exactly....

As I have it wired right now- when the bass is in 'mute' mode, the signal from the output jack (hot) is being grounded. My question is- what good does it do to put a resistor between that signal and the ground?


SGD Lutherie said:
The only time you use resistors is when you have a cap in the signal chain. The cap needs to be bled off, so you use a pull-down resistor.
Click to expand...

Thanks for clearing that up.
 

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