Toggle switch to select effect switching

[Rockers Rollin]

Hi all,

So, I've housed the guts of 2 Boss pedals in a 1U rackmount.  I've replaced the Boss foot switches with momentary switches mounted in the front of the 1U rack enclosure, along with the controls of the effects. 

I've also wired both these momentary switches to a single 1/4" input jack on the back of the enclosure.  This allows me to connect a foot pedal with a momentary switch to on/ off both effects at once. 

As below:



What I'd like to be able to do, is mount a toggle switch on the front of my rack enclosure to allow me to select what the foot switch controls - effect 1, both, effect 2, as per below.  However, I don't know if this is possible/ how I'd wire this?  Can anyone provide any help?

[RickL]

I think you can do it with either a three position, 3 lug, on-on-on switch like a Les Paul selector switch, or a 6 lug, on-on-on switch (the kind that can be wired as a 1p3t switch. But I think you also want a couple of diodes, even if you don't add the toggle.

First the diodes. My guess is that the way you have it wired, either panel mount switch will toggle both pedals. If you add a couple of diodes, anodes to the panel mount switches, cathode to the pedal, each panel mount switch should operate independently. Edit: no that won't work, but there has to be a way to do it. I think you want the diodes between the switches and the jack, anode to jack, cathodes to switch, but someone check my work 

The first switch option is easy. Just send the switch to one of the outer lugs of the switch, and the common to the tip of the jack. All the grounds connect together.

The second option is just as easy, if I'm picturing it right. Imagine the lugs, looking from the bottom, like this;

1 2
3 4
5 6

When the switch is in position 1, lug 1 connects to lug 3 and lug 2 connects to lug 4. In the middle position it is 1 to 3 and 4 to 6 (or 2 to 4 and 3 to 5, depending on the switch), in position three it is 3 to 5 and 4 to 6.

If you connect the switches to, respectively, [1 and 2] and [5 and 6] and the tip of the jack to [3 and 4] it should work. Technically you could just connect the diodes to lugs 1 and 6 (or 2 and 5 if the switch is set up the second way) and the tip of the jack to 3 and 4, but the first way is just as easy to wire and you don't have to know exactly how the switch works.

I'd use the second version because I think the switch is cheaper (and I have a couple) but you might have an old guitar toggle in your stash. A Tele type switch would work the same, but you'll have to cut a slot to mount it. Holes are easier to drill  .

[Rockers Rollin]

Thanks, that makes sense re the on/on/on toggal switch. A bit of research and it figured that out as you posted it.

The diode is a good shout, that is indeed what's happening. In position 1 the panal switch for effect 1 and foot pedal control effect 1 only. In position 3, the panel switch for effect 2 and the foot switch control effect 2 only. However, in middle position it all gets messy, effect 1 changes on selecting the middle position and both panel mount switches and the foot switch only control effect 2.

I guess this is where diodes come in. This is slightly out of my depth. Can anyone offer guidance?

[GGBB]

If you use a DPxT momentary, you essentially have two separate switches so you shouldn't have to deal with keeping the circuits apart with diodes.

[Rockers Rollin]

If you use a DPxT momentary, you essentially have two separate switches so you shouldn't have to deal with keeping the circuits apart with diodes.

The 2 switches (one for each effect) are SPST momentary. As per above, these are wired to a DPDT on/on/on toggel.

[RickL]

In position 1 the panal switch for effect 1 and foot pedal control effect 1 only. In position 3, the panel switch for effect 2 and the foot switch control effect 2 only. However, in middle position it all gets messy, effect 1 changes on selecting the middle position and both panel mount switches and the foot switch only control effect 2.

Most pedals that use a momentary switch for bypass have one end of the switch connected to ground and the other end connected to the switching circuit (Boss pedals do). If you have wired all the ground ends together and the circuit end of each momentary to the toggle, you have effectively wired the two momentaries in parallel in the middle position. If you have an external momentary also connected to the switch, you are effectively always using the middle position for that switch, so both effects should toggle each time you press it.

Try switching the wires to the switch on one of the momentaries. I bet you have one of the grounds reversed. And you might be able to get away without the diodes.

[GGBB]

If you use a DPxT momentary, you essentially have two separate switches so you shouldn't have to deal with keeping the circuits apart with diodes.

The 2 switches (one for each effect) are SPST momentary. As per above, these are wired to a DPDT on/on/on toggel.

I got that - was referring to the momentary footswitch as per above.

[ElectricDruid]

I think this is what's being proposed with the diodes:



The idea is that in the middle position of the Select Switch, both footswitches are shorted to ground. In either of the individual positions, left or right, one of the diodes will be reverse biased and stop the other footswitch from being shorted.

It's a sort-of Diode-OR type of thing.

[GGBB]

I think this is what's being proposed with the diodes:



The idea is that in the middle position of the Select Switch, both footswitches are shorted to ground. In either of the individual positions, left or right, one of the diodes will be reverse biased and stop the other footswitch from being shorted.

It's a sort-of Diode-OR type of thing.

Which is why I suggested a DPxT momentary footswitch to avoid diodes:

[ElectricDruid]

Which is why I suggested a DPxT momentary footswitch to avoid diodes:

Why avoid two diodes that cost pennies?!?

But yeah, that would work too.

[Rockers Rollin]

In position 1 the panal switch for effect 1 and foot pedal control effect 1 only. In position 3, the panel switch for effect 2 and the foot switch control effect 2 only. However, in middle position it all gets messy, effect 1 changes on selecting the middle position and both panel mount switches and the foot switch only control effect 2.

Most pedals that use a momentary switch for bypass have one end of the switch connected to ground and the other end connected to the switching circuit (Boss pedals do). If you have wired all the ground ends together and the circuit end of each momentary to the toggle, you have effectively wired the two momentaries in parallel in the middle position. If you have an external momentary also connected to the switch, you are effectively always using the middle position for that switch, so both effects should toggle each time you press it.

Try switching the wires to the switch on one of the momentaries. I bet you have one of the grounds reversed. And you might be able to get away without the diodes.

I have just tried this, I swapped the wires on one of the momentaries but I'm still getting the same issue. Position 1 and 3 work fine, but in the middle position where it should control both effects, its only controlling effect 2 and effect 1 doesn't change. However, on switching to the middle position, effect 1 changes.

[Rockers Rollin]

This is what I currently have:



(the 6 pin is obviously the DPDT on/on/on toggle)


Also, apologies, I have very limited knowledge of all this!!  Your help is much appreciated - I'm trying to learn, but as you can see, I'm not getting very far! 

[ElectricDruid]

I have just tried this, I swapped the wires on one of the momentaries but I'm still getting the same issue. Position 1 and 3 work fine, but in the middle position where it should control both effects, its only controlling effect 2 and effect 1 doesn't change. However, on switching to the middle position, effect 1 changes.

This looks like the two effects are interfering with each other. When you switch to the middle position, the two become directly connected. Something about that is causing one of them to switch state.
Try it with the diodes - they should help keep the two circuits apart and prevent problems.

[Rockers Rollin]

I have just tried this, I swapped the wires on one of the momentaries but I'm still getting the same issue. Position 1 and 3 work fine, but in the middle position where it should control both effects, its only controlling effect 2 and effect 1 doesn't change. However, on switching to the middle position, effect 1 changes.

This looks like the two effects are interfering with each other. When you switch to the middle position, the two become directly connected. Something about that is causing one of them to switch state.
Try it with the diodes - they should help keep the two circuits apart and prevent problems.

Any sort of diode, or does it have to be specific ones/ types?
I'm still not clear on their placement.

[GGBB]

Why avoid two diodes that cost pennies?!?

Diodes would be cheaper, but a lot more work judging from this thread.

[ElectricDruid]

Any sort of diode, or does it have to be specific ones/ types?
I'm still not clear on their placement.

1N4148 or 1N914 would be good. Any small signal silicon diode will work. Here's the diodes on your diagram:

[Rockers Rollin]

Any sort of diode, or does it have to be specific ones/ types?
I'm still not clear on their placement.

1N4148 or 1N914 would be good. Any small signal silicon diode will work. Here's the diodes on your diagram:

Much appreciated. I've just ordered these up, they'll be here tomorrow.... I'll report back!

[Rockers Rollin]

Any sort of diode, or does it have to be specific ones/ types?
I'm still not clear on their placement.

1N4148 or 1N914 would be good. Any small signal silicon diode will work. Here's the diodes on your diagram:

So, I've now added the diodes. However, the middle position still isn't playing ball.

In the middle position, effect 1s momentery switch controls effect 1 independently, and effect 2s momentary switch controls effect 2 independently. All good.

However, using the remote momentary switch (connected to the DPDT toggle) effect 1 is controlled, but effect 2 only changes if its on, if effect 2 is off the remote momentar doesn't switch it on. So, if I turn it back on, the remote momentary will switch it off again when pressed. Effect 1, continues to operate fine.

For reference, both effects are Bos LS-2s. So when I say effect 2 wont switch on, what I mean is when in Mode A<>B, it'll switch from A to B, but not B to A.

I've noticed that the second LS-2 (effect 2) looks to be an older model and is wired differently. Unsure of that makes any difference given they're both using momentaries.  On effect 1, both momentary ground and positive are wired to the board. On effect 2, positive is wired to the board, but earth is wired to the input jack.

[ElectricDruid]

I've noticed that the second LS-2 (effect 2) looks to be an older model and is wired differently. Unsure of that makes any difference given they're both using momentaries.  On effect 1, both momentary ground and positive are wired to the board. On effect 2, positive is wired to the board, but earth is wired to the input jack.

Ok, so does this quirk follow that pedal if you swap 1 and 2 over?

If it does, it doesn't look like it's something in our wiring, but rather something in the pedal. If the problem remains on the "Effect 2" position despite having swapped them over, then it must be something we've done.

[Rockers Rollin]

I've noticed that the second LS-2 (effect 2) looks to be an older model and is wired differently. Unsure of that makes any difference given they're both using momentaries.  On effect 1, both momentary ground and positive are wired to the board. On effect 2, positive is wired to the board, but earth is wired to the input jack.

Ok, so does this quirk follow that pedal if you swap 1 and 2 over?

If it does, it doesn't look like it's something in our wiring, but rather something in the pedal. If the problem remains on the "Effect 2" position despite having swapped them over, then it must be something we've done.

Looks like it's possibly something in the pedal? I swapped the positions on the DPDT toggle, same - followed that pedal. I also removed the toggle and connected them directly to the remote momentary with the diodes, same issue.

Could it be that both pedals are now in the same chassis (1u rack) and share a same ground (the chasis)?