Adding a LED to a Marshall footswitch

[warioblast]

Hi,
I want to add a LED to a Marshall single button footswitch. How can it be done ?
All help welcome,
Fabrice

[Ice-9]

if its only got a single pole switch in it, then i would replace the switch with a ne wdpdt footswitch and use the second pole to wire an led etc. but this way you will also have to put  a battery in the footswitch. or check the schematic on shematic heaved to see what the footswitch is actually switching it may be fine to wire an led direct.

If i knew what the amp and footwsitch model numbers were it would help.

[warioblast]

Yes it has a SPDT switch. It's your basic Marshall footswitch. My amp is a DSL 50 head.

[newfish]

Could you use a couple of button cells for this?

Tiny space requirements and lack of components (shouldn't need a current limiting resistor, right?) - and the 3v you'd have from the two cells would be enough to get through the diode...

Just a thought.

[vanhansen]

First, put a basic instrument cable in to the footswitch jack of your amp.  Using your DMM, check for any voltage coming down the line on the other end of cable with the amp on:  + to top, - to sleeve.  It may require opening the footswitch, plugging it in to the amp and switching it while the DMM is hooked up to the +/- points.  Reason being is that the voltage is either present or it's not depending on the state of the switch.  My guess is there will be some voltage, but a small amount and clearly enough to light up a LED.

Then, all you gotta do is wire up the LED across the + and - points of the switch.  I've done this myself with a vacuum cleaner switch (Hoover brand), 1/4" jack and a LED.  Real easy to wire up.  You may not even require a limiting resistor but that'll depend on the voltage coming from the footswitch jack and what the LED can handle.

[Mark Hammer]

Do note that although pedals use 9v, and that's normally whatpowers the LED, the LED itself doesn't need 9v to shine.  So, if one was obliged to power a status LED via battery inside the footpedal, a pair of AAs or quartet of AAAs might be a better solution and wold certainly fit inside the case.

A question.  A quick lookup of the DSL50 indicates that a) it comes with a footpedal, and b) the rear skirt shows jacks for remote-switching both reverb and channels.  So, uh, what happened?

[warioblast]

It's done. http://acapella.harmony-central.com/forums/showthread.php?p=29624122#post29624122