I need help to wire a footswitch with LEDs for my Vox ac15

Nicofromfrance · Post by **Nicofromfrance** » 19 Mar 2012, 17:05

Hi all, I'm new on this forum.

I want to build a footswitch with 2 LEDs for the Reverb and Tremolo effects of my Vox ac15, as the current one I got (a no name one) doesn't have LEDS, which is not very useful when I want to know if reverb is on or off, as an example. I precise that I'm also re-housing the wiring in a smaller box to reduce the space it takes on my pedalboard.
The footswith will have one LED per effect to check if it is on or off, and normally these LEDs will be powered by the amp, as the current footswitch I got is powered this way by the ac15.

I'm trying to figure out how to wire all this in my litte box. I'm a begginer in DIY electronic, and that footswitch is the pretext to start well

So far I got this wiring diagram (inspired by another one I found):

Can someone tell me if it is right or wrong ?
Also, in the event that the amp wouldn't power the LEDs, can you tell me how to wire a 9V battery to the rest?

Thanks!

Groovenut · Post by **Groovenut** » 19 Mar 2012, 17:41

If the amp provides power to the foot pedal, your schematic will work. The LEDs will light when the switch is open. You need to determine how much voltage is provided by the amp to determine the dropping resistor for each led. For example, say the amp provides 12v to the pedal and you are using standard LEDs the formula goes something like this, 12v - 1.7v(LED forward voltage) = 10.3v, 10.3 / 20mA = 515ohms (510R is closest regular value) for each LED. It looks from the schematics I could find, that the switching is actuated through a transistor. The trem switching transistor looks like it has a pull up resistor and might provide power to the pedal. The reverb looks like it does too, but will need to be measured to be certain. If the amp doesnt provide power, you could easily wire a 9V battery in the pedal and use the empty side of the switches for your LEDs.

Nicofromfrance · Post by **Nicofromfrance** » 19 Mar 2012, 18:42

Thanks a lot Groovenut! I'll figure out about the voltage provided to the footswitch.
I ended up finding this diagram http://s5.postimage.org/edr7o9z1z/VOX_V ... iagram.jpg which is the Vox VFS2A footswitch one, in other words the one I want to build. the switches used here are SPDTs, I think using DPDTs instead of them won't cause me issues? at least they could be use to wire a 9V battery if needed.

By the way could you tell me how to wire a 9V battery to the rest in the case I will need it? I'm a beginner so it's not obvious to me!

Other question: how to know on which lug of the dpdt to solder which wire? is there any direction to follow on these switches ?

Thanks!

Groovenut · Post by **Groovenut** » 19 Mar 2012, 19:16

Here is one way you could wire a battery for LED power in the foot switch. If the LEDs come on opposite of the switch function just reverse point A and B.

You would have to remember to switch off the LED to avoid battery drain and would probably want to set the dropping resistor to use the smallest amount of current to light the LED.

Nicofromfrance · Post by **Nicofromfrance** » 21 Mar 2012, 09:48

It works this way, I wired the two LEDs in my current footswitch and they are powered by the amp. now I'm awaiting to receive the dpdts switches and some other components to re-house the footswitch in a smaller box.

Thanks Groovenut!