software

Ive got almost all the info to make my footswitch. This one thing about LEDs is still bothering me. All the pins from the amp push almost 4 volts, and i heard most leds cant handle more than 2/3 volts. I know i could put a resistor in front of the LED, but i dont know how much voltage needs to be returned to the negative pin in order to close the circuit for the switch to work. The schematic has the LED and push button switch in parallel, but since the LED would always be connected to a positive and ground, wouldnt it always be on? Here is the schematic the company has-Can you guys make sense of this? If i wire it just like that should it work correctly? Do i need a resistor so the LED doesnt burn out? Thanks guys.

You can use this calculator to determine the size of the resistor needed to keep from frying the LED.
I dunno if it'll work the way you have things wired up because the LED might pass enough current that the amp will think that the switch is always closed. OTOH, if you wire the LED in series with the switch, the current going through the LED might be enough to trigger the circuit. It'll probably take a bit of experimentation on your part to come up with something that'll work with your amp.
It's pain like this that led me to decide to mod a pedal switch that works with my amp rather than building one from scratch. It might be more expensive but I know I'll end up with something that works.