I am modifying a guitar multi-effects unit for external switching of presets. The external footswitch uses 2 spst momentary switches and a trs cable. The problem I am having is on the multi-effects side.
The footswitches send either tip and sleeve or ring and sleeve, meaning that sleeve is always sent.
When I detach the sleeve connection from either of the buttons in the multi-effects unit the other button works correctly and vise versa. I am wondering if i could use a relay on the sleeve connection. I have attached a diagram of what is going on any help would be much appreciated.

 

I am modifying a guitar multi-effects unit for external switching of presets. The external footswitch uses 2 spst momentary switches and a trs cable. The problem I am having is on the multi-effects side.
The footswitches send either tip and sleeve or ring and sleeve, meaning that sleeve is always sent.
When I detach the sleeve connection from either of the buttons in the multi-effects unit the other button works correctly and vise versa. I am wondering if i could use a relay on the sleeve connection. I have attached a diagram of what is going on any help would be much appreciated.

First off, you're not sending eg.the sleeve anywhere (I hope), but are connecting sleeve to either of the other two.
Not knowing what goes on inside your FX, it is hard to say what's happening, as it sounds like it's wired how it should be - could it be that it has to go open to signal a change?

According to what you write, a solution would be to get double pole momentary switches and switch the sleeve signal along with the tip or ring.

If you can post a schematic of your FX, at least the part that receives the momentary signal, it would be easier to help.

 

First off, you're not sending eg.the sleeve anywhere (I hope), but are connecting sleeve to either of the other two.
Not knowing what goes on inside your FX, it is hard to say what's happening, as it sounds like it's wired how it should be - could it be that it has to go open to signal a change?

According to what you write, a solution would be to get double pole momentary switches and switch the sleeve signal along with the tip or ring.

If you can post a schematic of your FX, at least the part that receives the momentary signal, it would be easier to help.

Soren,
Thanks for the reply. I agree that using dpdt switches for the external switching would probably work but unfortunately I cannot as the external footswitch also sends midi messages to another unit and I really dont want to mess with it.

As for the effects unit schematic I have not been able to find anything on lne that could help me.

The effects unit switches do two things, when pressed separately they increment or decrement the patches. When they are pressed together they put the unit into tuner mode.

I can get each of the footsitches to work separately one at a time but when I hook them both up pressing either external footswitch puts the unit into tuner mode, meaning they are both being activated at the same time.

So close but so far away.

 

I agree that using dpdt switches for the external switching would probably work but unfortunately I cannot as the external footswitch also sends midi messages to another unit and I really dont want to mess with it.

I'm not quite sure of what you're trying to connect - is it an FX that you put some connectors in bridging the existing buttons?
And the pedal sending MIDI would be a ready made device?
Please post make/model of both.

I can get each of the footsitches to work separately one at a time but when I hook them both up pressing either external footswitch puts the unit into tuner mode, meaning they are both being activated at the same time.

So close but so far away.

The more info you can post the nearer we can get you

The reason that you have to disconnect the sleeve may indicate that the buttons in the FX may do more than just making a contact - perhaps it breaks a connection as well, but I'm shooting blind here, as I don't have enough info.
So, please describe your setup more.

 

I am modifying a guitar multi-effects unit for external switching of presets. The external footswitch uses 2 spst momentary switches and a trs cable. The problem I am having is on the multi-effects side.
The footswitches send either tip and sleeve or ring and sleeve, meaning that sleeve is always sent.
When I detach the sleeve connection from either of the buttons in the multi-effects unit the other button works correctly and vise versa. I am wondering if i could use a relay on the sleeve connection. I have attached a diagram of what is going on any help would be much appreciated.

What is the make and model number of the effects unit?

 

What is the make and model number of the effects unit?

The effects unit is the vox tonelab st, and the external footswitch is the amt fs-2midi.

 

I'm not quite sure of what you're trying to connect - is it an FX that you put some connectors in bridging the existing buttons?
And the pedal sending MIDI would be a ready made device?
Please post make/model of both.


The more info you can post the nearer we can get you

The reason that you have to disconnect the sleeve may indicate that the buttons in the FX may do more than just making a contact - perhaps it breaks a connection as well, but I'm shooting blind here, as I don't have enough info.
So, please describe your setup more.

I think you are right about the buttons also breaking a connection. When both are pressed together the unit enters tuner mode the when either of the buttons are pessed the unit exits tuner mode back to preset mode. I think thats where the break happens.

The effects unit is the vox tonelab st and the external footswitch is the amt fs-2midi.

Thanks

 

When both are pressed together the unit enters tuner mode the when either of the buttons are pessed the unit exits tuner mode back to preset mode. I think thats where the break happens.

As far as I can see, that particular footswitch does...

- simultaneous short pressing of two buttons (buttons holding time must not
exceed 1.5 seconds) is used to confirm the data entered or move to the next
parameter in setup mode;
- long pressing of a button (for over 1.5 seconds) in the main mode is used to
enter command setup assigned to the button; in setting mode it is used for fast
scrolling of parameter values;
- simultaneous long pressing of both buttons (for over 1.5 seconds) in main mode
- entrance to the device modes setting.

Seems like it does that in all modes, so entering tuner mode from the FS2 maybe won't happen, but I could be wrong.

The effects unit is the vox tonelab st and the external footswitch is the amt fs-2midi.

Where on the ToneLab do you connect the lead??
I cannot find a TRS connector for this - did you add one (or repurposed another existing) connector?

Do you own or have access to a multimeter?

BTW. the PCB mounted switches in your drawing looks odd. Usually it's the middle pin (of each row of 3) that is switched between the outer 2 pins.