installing kill switch

kev_s88

how easy would it be to install a kill switch in my Ibanez s-520.i know the switches themselves can be pretty cheap.is this a DIY job or would i be better off getting it done professionally?

feylya

Really easy to install if

a) You are comfortable with simple electronics
b) You are comfortable with soldering
c) You are comfortable with drilling a hole in your guitar

A kill switch is simply a switch on the live wire going to the guitar output that shunts it to ground. Easy peasy really.

kev_s88

sounds good.was looking for guides on the net but could not find any for my guitar. but as long as its easy enough im happy.thanks for the advice

Paolo_M

kev_s88 wrote: »

how easy would it be to install a kill switch in my Ibanez s-520.i know the switches themselves can be pretty cheap.is this a DIY job or would i be better off getting it done professionally?

It's pretty easy to do. The concept is to switch your guitars "hot" lead to ground when you require the "kill". This way shorts all the signal to ground when engaged giving a noise free switch. This different from just opening the loop as I've seen some descriptions on the web. This link gives you a good overview and you'll be able to see if you're up for it or not.
http://www.instructables.com/id/Guitar-Killswitch-Installation/
Any SPST switch (NO if using mometry type) will work but I think one the guy in this site chose is aweful looking!!:eek:

feylya

I would actually recommend a DPST switch. That way, you can put the live from the amp to ground - this kills any chance of hum which is possible if you just discount, especially if it's a cheaper guitar.

Paolo_M

feylya wrote: »

I would actually recommend a DPST switch. That way, you can put the live from the amp to ground - this kills any chance of hum which is possible if you just discount, especially if it's a cheaper guitar.

I'm not sure I get you, where's the second pole coming from?

kev_s88

feylya wrote: »

I would actually recommend a DPST switch. That way, you can put the live from the amp to ground - this kills any chance of hum which is possible if you just discount, especially if it's a cheaper guitar.

well i wouldnt consider my guitar to be of the cheaper variety but it certainly wasnt breaking the bank.but its the only heavy-ish guitar i have and the kill would be sweet to have in it.even if i dont use it regularly.

thanks for all the advice anyways.all the guides have been saying to get the SPST momentary switch.so i'll go with that and just sort out the rest of the stuff

thanks again

feylya

Paolo_M wrote: »

I'm not sure I get you, where's the second pole coming from?

Use the second pole to connect the hot wire to the earth.

Paolo_M

feylya wrote: »

Use the second pole to connect the hot wire to the earth.

Well that was the one pole I was thinking of, where's the first pole from so?
Could you show a circuit diagram?

feylya

well, you'l need a conection from the pickups, one to the output jack and one to earth. that's three in my book. i'll do a diagram if I get five minutes

Eoin Madsen

Don't think a DPDT would make any difference. It's the same ground. There's no need to split the output jack from the pickup signal - the signal wire just has to touch ground.

(The amp and the guitar are both grounded through the same wire)

feylya

But if it's SPST, then the hot wire to the amp is just disconnected to nothing with no ground.

Eoin Madsen

If you use a SPST, the hot wire doesn't get disconnected at all.

Eoin Madsen

You break the signal path somewhere along the way and rejoin by tying both ends of the break to one contact of a SPST. Then you connect the other contact to earth. When you throw the switch, the signal runs to ground.

The net result of using a DPDT to seperately send each side of the break to ground is exactly the same. It just takes up more space.

feylya

But a SPST switch will just move the blade inside the switch to the other pole so it won't be connected to anything.

Eoin Madsen

feylya wrote: »

But a SPST switch will just move the blade inside the switch to the other pole so it won't be connected to anything.

An SPST switch is either on or off. When the kill switch is on, the signal is cut because it touches ground. When the kill switch is off, the switch does not exist in the circuit.

EDIT: Added illustration. Excuse my dodgy MS Paint skills...

feylya

And my understanding was that it just disconnected.

Paolo_M

The way I'm thinking of is to take a wire from the hot lug of the volume to one side of a SPST switch, the other side goes to ground on the back of the volume pot usually. This is open normally and, as Eoin, said effectivley doesn't exist in the circuit. When the switch is closed the hot is shorted to ground, or strictly speaking takes the path of least resistance to ground thus giving you noiseless "kill". To the amp the circuit looks as though no cable is connected as the tip is shorted to the sleeve just like the jack is normally is with no cable in.
Here's a drawing for strat and LP guitars, the LP of courses with the hot from the toggle to kill both pick-ups.

feylya

That would work alright.

Eoin Madsen

feylya wrote: »

And my understanding was that it just disconnected.

That would not be a good way to wire it.

Paolo_M

Paolo_M wrote: »

The way I'm thinking of is to take a wire from the hot lug of the volume to one side of a SPST switch, the other side goes to ground on the back of the volume pot usually. This is open normally and, as Eoin, said effectivley doesn't exist in the circuit. When the switch is closed the hot is shorted to ground, or strictly speaking takes the path of least resistance to ground thus giving you noiseless "kill". To the amp the circuit looks as though no cable is connected as the tip is shorted to the sleeve just like the jack is normally is with no cable in.
Here's a drawing for strat and LP guitars, the LP of courses with the hot from the toggle to kill both pick-ups.

Forgot to mention that this effectivley the same method as shown in the instructables site except hot is taken at the jack. This may suit better depending on where you want to mount the switch.

feylya

Eoin Madsen wrote: »

That would not be a good way to wire it.

I know... That's why I'm saying have an earth lug to make sure.

Eoin Madsen

feylya wrote: »

I know... That's why I'm saying have an earth lug to make sure.

Which you can do with an SPST just as easily as a DPST... which was what we were talking about, no?

feylya

The question is though, where do you get the ground connection from on the SPST? One pole goes to the pots, one to the output.

Paolo_M

feylya wrote: »

I know... That's why I'm saying have an earth lug to make sure.

Can you post a circuit diagram, 'cos I've no doubt that it's a perfectly valid way of wiring the switch it's just not clear to me from the description so far how it would work.

Paolo_M

feylya wrote: »

The question is though, where do you get the ground connection from on the SPST? One pole goes to the pots, one to the output.

Ah there's the problem. There's only one live "pole" which is "thrown" to ground. No need for a second pole.

Eoin Madsen

feylya wrote: »

One pole goes to the pots, one to the output.

No they don't. Are you even reading my posts? I drew a picture and all.

feylya

Ah, now I get ya. I was assuming that diagram to be the internals of the switch. That'll work too.

Eoin Madsen

Phew. I was worried I might be losing my elucidativity*.

*not a real word