Hello all, I have been asked to build a simple kill switch for a guitarist friend who wants to be able to silence his guitar downstream of his pedal board so he can silently tune etc... I built a box with 2 jacks connected together (in and out) and a switch that shorts the signal to ground when turned "on". The problem is he complains it makes a click that is audible through his amplifier at the moment he steps on it. No matter if he stomps it hard or gently presses it makes a noise when he turns his guitar "off".
Is this the switch contacts bouncing on connection or what? I do not hear a noticeable click like he does but he swears it is no good the way it is... SO
Is there a better made switch (I used this one: Peavey On/Off Single-Button Replacement Switch) or must he go with an active circuit for a silent kill switch? As a purist guitar type he demands straight through designs (so called true bypass pedal designs only please...) so any design I can think of that would be truly silent would not be true bypass...
Is there another way?
Is this the switch contacts bouncing on connection or what? I do not hear a noticeable click like he does but he swears it is no good the way it is... SO
Is there a better made switch (I used this one: Peavey On/Off Single-Button Replacement Switch) or must he go with an active circuit for a silent kill switch? As a purist guitar type he demands straight through designs (so called true bypass pedal designs only please...) so any design I can think of that would be truly silent would not be true bypass...
Is there another way?
Last edited:
My design is identical to Fig 1-B (shunt switching). This is what I built. I know better than to use 1-A as that would be an invitation to more noise. I don't understand how using 1-C (both series and shunt switching) would stop the click noise during actuation. Can anyone give an explanation here?
I believe the Figure 1-B diagram as shown is not in the muted position (Fig 1-A and 1-C are in mute position but not 1-B).
I believe the Figure 1-B diagram as shown is not in the muted position (Fig 1-A and 1-C are in mute position but not 1-B).
Last edited:
Maybe there is some DC in the amp connection. Try a coupling cap at the amp input and see if the noise goes away.
Can you suggest a value? Remember the customer is very concerned about tonal coloration so the cap value would need to be such that it didn't change his tone noticeably...
Last edited:
This is mainly for troubleshooting. If the noise goes away with the cap, there's DC on the input and a tech should check it.
Try either a 1uF film or a 10uF nonpolarized electrolytic.
If that doesn't help, try a 2k resistor in parallel with the switch. This will help if the amp has a very high input impedance.
Last edited:
Not very well other than it is extensive. He plays in a very successful cover band in the Detroit area. It most likely has a tuner, compressor, 2 different overdrives, phaser, phlanger, echo (probably 2 different echo settings or 2 pedals), and an EQ. A full salad of noise makers...
why sereis-shunt is better
In the examples, 1C-series-shunt method-is better because of the inherent self-capacitance of the series switch, which could be several pico farads. Remember a capacitor is two conductors separated by an insulator- in this case, air. The resistance of the series open switch-it's not infinity- and the capacitance of the switch form a high-pass filter and some signal gets through- the pop. The second switch-shunt-routs the pop to ground. Use a DPDT and use one NO and one NC contact. It's the easiest and cheapest option. You can try other options if this doesn't satisfy your guitar player. You might want to inform him being a purist- true bypass mechanical switching only- has its consequences.
The other options are solid state, JFET, LDR, etc. As someone stated earlier, a cap will change the tone of the signal, and if the small pop irritates him/her the wrong cap surely will.
In the examples, 1C-series-shunt method-is better because of the inherent self-capacitance of the series switch, which could be several pico farads. Remember a capacitor is two conductors separated by an insulator- in this case, air. The resistance of the series open switch-it's not infinity- and the capacitance of the switch form a high-pass filter and some signal gets through- the pop. The second switch-shunt-routs the pop to ground. Use a DPDT and use one NO and one NC contact. It's the easiest and cheapest option. You can try other options if this doesn't satisfy your guitar player. You might want to inform him being a purist- true bypass mechanical switching only- has its consequences.
The other options are solid state, JFET, LDR, etc. As someone stated earlier, a cap will change the tone of the signal, and if the small pop irritates him/her the wrong cap surely will.
I'll bet this is the source of the pops, try it with a 100k resistor load across the shorting switch.
Well I had a 100K ohm resister in my parts box so this is the method I used for the first attempt at fixing the issue. In my tests the switch was quieter than without the resister so I returned it to its owner for evaluation. I am waiting to hear from him on whether it is fixed...
Thank you all for your input, I greatly appreciate it. I will report back after he evaluates it.
Thank you all for your input, I greatly appreciate it. I will report back after he evaluates it.
You can go lower in value, it depends on the circuit before and after. The 100k is unlikely to cause much bass roll off.
If the capacitor feeding the switch is 10uF or more, you could go down to 10k.
Thank you again rayma, I will use this if needed. I expect to hear from my guitarist pal in a few days, I gave him back the kill switch yesterday evening.
- Status
- This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.