No Pop Guitar Kill Switch

[petemoore]

  I have a switch wired as SPST, it is a momentary type connected from jack tip to jack ground. It works but it also clicks every time ground is touched to SP inside the switch.
  Is there an easy fix for eliminating the clicking?

[PenPen]

I made one of these for a friend very recently. I used a momentary DPDT. Wired as follows

Code Select Expand


       |----|
In  <--|    |----> Out
       |    | -
              |
              |
              |
              -
              GND


Basically I read the GeoFX article on the mic muter, and figured series/shunt would be the best. He was extremely happy with it, even recently recorded with it, with Steve Albini as the producer, which made me extremely nervous that it would cause noises, but he reported it worked fantastic with no pops at all. Anyway, thats what I did.


EDIT: Err, it just occured to me that isn't what you were looking for. Sorry. The only thing I would say is causing it, based on what RG has posted about it, is that the click is mechanical, the only thing I could think of to fix it would be get a better switch.

FWIW, I used a Taiwan "XWing" DPDT for my friend's box.

[Processaurus]

I made one of these for a friend very recently. I used a momentary DPDT.

Did you find a good size panel mount switch?  I've had trouble finding a good size switch that has a nice feel.

[LyleCaldwell]

  I have a switch wired as SPST, it is a momentary type connected from jack tip to jack ground. It works but it also clicks every time ground is touched to SP inside the switch.
  Is there an easy fix for eliminating the clicking?

Try a 1M resistor between the poles of the switch.

[PenPen]

I made one of these for a friend very recently. I used a momentary DPDT.

Did you find a good size panel mount switch?  I've had trouble finding a good size switch that has a nice feel.

I just ordered the Taiwan "XWing" momentary from Smallbear. The feel wasn't really bad, and like I said, the 'customer' was insanely happy with it, he now uses it instead of his Earnie Ball Volume pedal now to mute out.

[R.G.]

If you can afford to mount a couple of lithium coin cells in the guitar, use a couple of JFETs for your switch. The JFETs are normally biased off by the batteries (that's the only function the batteries serve) and so do not shunt the guitar signal. When you want to mute the guitar, have the switch disconnect the battery from the gate. You can even use a 1M/0.01uF slow-down network so that the switching happens over a few milliseconds. The batteries provide no power - only the current in a reverse biased junction that's designed to be low leakage - so they will last the shelf life of the batteries, which is years, if not decades for lithium ion coin cells.

But the 1M across the mechanical switch might work too.

[robbiemcm]

Just out of interest what would happen if you disconnected the ground of your pickup instead of anything in the signal path? Would that just make it noisy or would that stop the pickups and leave nothing to make any pops?

[PenPen]

just out of curiosity, how exactly do you have the switch wired?

Code Select Expand


PU ---> |
TIP --> |
GND --> |


Like that? If so, I'd say go with either RG's jfet idea or the 1M resistor.

However, it just occured to me you could be doing it like this:

Code Select Expand


TIP --> |
GND --> |


If thats how you are doing it, the click could be from the fact that you are just shunting and not disconnecting the pickups as well. If you get a SPDT, you could wire it like the first example, and you shouldn't have any clicks.....

[St. Stephen]

If you can afford to mount a couple of lithium coin cells in the guitar, use a couple of JFETs for your switch. The JFETs are normally biased off by the batteries (that's the only function the batteries serve) and so do not shunt the guitar signal. When you want to mute the guitar, have the switch disconnect the battery from the gate. You can even use a 1M/0.01uF slow-down network so that the switching happens over a few milliseconds. The batteries provide no power - only the current in a reverse biased junction that's designed to be low leakage - so they will last the shelf life of the batteries, which is years, if not decades for lithium ion coin cells.

But the 1M across the mechanical switch might work too.

Could someone explain how to do this?

I installed a normally-open momentary switch in my guitar that connects the signal to ground and it pops terribly.  BTW, it  already has 9V battery in it I could get power from.

[petemoore]

  I've been using it, and it pops only mildly, mildly enough to be a 'MoJo'...

[R.G.]

Could someone explain how to do this?
I installed a normally-open momentary switch in my guitar that connects the signal to ground and it pops terribly.  BTW, it  already has 9V battery in it I could get power from.

Having other stuff on board that's powered by that 9V battery actually complicates things because you now have to arrange to use the same battery and not compromise either the switch or the other stuff.

You will need
JFET - one of 2N5484/85/86, 2N5457, MPF102; extra low Vgsoff devices like J201 are not good choices in this case
10uF electrolytic capacitor - two of them
0.01uF cap 1 each
1M resistor 4 each
1N914 or 1N4148
SPDT switch

In doing the wiring, we have to know how the battery is grounded. For this case, the battery is assumed to be hooked up with its negative terminal to the guitar signal ground. This will not work unless that is true, and another wiring arrangement is needed.

Wire it up:
Signal Path
guitar output -> 10uF cap negative; 10uF cap positive -> JFET drain; JFET source -> 10uF cap positivel; 10uF cap negative -> output, presumably jack on guitar; 1M resistor from output signal on jack to jack ground
JFET gate
JFET gate-> diode anode; diode cathode -> 0.01uF cap -> ground
Switch
One switch throw -> battery positive; second switch throw -> ground; switch pole -> 1M resistor -> junction of the diode cathode and 0.01uF cap
JFET biasing
JFET drain -> 1M resistor -> battery positive; JFET source -> 1M resistor -> battery positive

The JFET is arranged in series with the output signal. The caps prevent the DC voltages from getting out on your signal line. The 1M resistors bias the JFET properly as a switch and also prevent DC from getting out on your output signal. The 10uF capss and three of the 1M resistors are only needed because of the other stuff on board using the battery. The switch either attaches the JFET gate to ground or the battery + through a 1M resistor and that diode. The capacitor slows down how fast the JFET gate can move, so that it turns on and off over a few milliseconds and the transients move so slowly that they're not transmitted in the audio path. The diode lets the gate be pulled to ground or float up to a level where the JFET is happy. The JFET drain and source are pulled to battery + by the 1M resistors on them, and this voltage is blocked by the 10uF caps. This is necessary so the switch can pull the JFET gate negative compared to the JFET drain/source DC voltage. The 1M on the output is there to make sure that any residual leakage on the output is pulled to ground.

It might be a good idea to use 4.7M resistors instead of 1M's for lower loading on the pickup signal. You're in a tradeoff race of capacitor leakage of the 10uF's against the resistance of these resistors. When the caps are new, you could probably use 10M's. As they age, you might need 1M's.

If the battery was exclusively for the use of the switch circuit, you could just use the JFET, the diode, the switch, the gate 1M and the 0.01uF cap.

[St. Stephen]

Does this look right?



If so, I still need to find a switch like that.

[R.G.]

Very close! The 0.01uF cap and the diode are swapped, and the output cap is grounded.

Exchange the 0.01F cap and diode's positions, leaving the diode pointing down like it is now.

Move the 10uF on the output side into series with the output lead, positive toward the circuit, negative out. Add one more 1M to ground right across the output.

[waldo041]

maybe a newb answer, but what about the silent switch plug by neutrik? or am i way off base?

http://www.neutrik.com/startbyemail.asp?country=us&urllink=http%3A//www.neutrik.com/content/products/products_entry.asp%3Fproductid%3D210_1485702010%26sublevelid%3D204_4911

just trying to help, i hear they are good for active electronic guitars.

peace,
waldo