Channel Select Footswitch

Started by kento810, August 06, 2010, 07:09:34 PM

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kento810

I am intersted in trying to make some pedals, but i would like to start with something really basic. Can anyone give some pointers on making a basic footswitch like a Marshall Ped801.

http://images.guitarcenter.com/products/optionlarge/Marshall/266807.jpg

Basically 1 footswith and 1 led. This particular footswitch has a cable attached to the pedal. I was wondering if I would be able to use a smaller enclosure (like a Hammond 1590a) and use a regular jack input. My Marshall Ped801 cable went out on me, I would prefer to just plug in a cable to the foot switch. I would also like to use a smaller enclosure to save more space on my pedalboard. I noticed when I opened the footswitch, there was a resistor. I don't know what resistor would be best for a 5mm LED.
What switch would be best to use?

Any advice, would be greatly appreciated!

Thank you

novemberlima

#1
Yes you can use a new smaller enclosure, just make sure you can fit all of the components in! If you prefer, you are able to salvage your existing channel switch. If you mount a jack on to the enclosure, you can then find where the lead terminates inside the pedal, and re wire it so those contact points instead go to the lugs on your newly installed jack. Then you can use any ordinary instrument lead to connect the pedal to your amp.

Also, the resistor is wired in series to the LED to control the voltage the LED receives. To find the value of the resistor needed, you subtract the working voltage of the LED from the voltage of the power source, then divide by the current rating of the LED. So, for a 9V power supply, and a 2V 20mA LED:
9V / 2V = 7V;

Then, according to Ohm's Law, V = IR, or voltage = current multiplied by resistance. To find the resistance, divide the voltage by the current:

7V / 0.02A (20mA) = 350 Ohms.

Finally, as the brightness of the LED is proportional to the current supplied, I would limit the current to less than 20mA to produce a slightly dimmer light. Therefore, you should use a slightly higher resistor value. This does not really apply to you as you are not using a battery power source, but in effects pedals it is usually recommended to help reduce the drain on the battery.

kento810