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need help building foot controller for bass amp

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New Member
Hi all, here's the deal...

I am building myself a foot controler for a "swr mo bass amp"
see: (http://www.swrsound.com/products/proseries/mobass.html)
I only want the bottom 6 switches with led's.
It hooks up the the amp via db9 connecters.
the pins do the following.(hang on this is about to get long winded, but I like to be thourough)
pin# disc.
1 +
2 drive (on/off)
3 synth (on/off)
4 chorus (on/off)
5 dual mode (on/off)
6 (I don't know)
7 subwave (on/off)
8 eq (on/off)
9 -

now... the switching occurs like so (pin 1+ pin 2=drive on)
(pin 9+ pin 2=drive off)
OR... (pin 1+9)+pin 2= effect on/off via a momentary switch.
ie. push the switch once the effect goes on, press it again the effect goes off.
see?? Great!!!
Now HERE is where I am stumped!!!!\
How do I wire up an LED into this mess so that the led lights up when the effect is on and shuts off when the effect is off?
If I hold an led to pin 1 and pin 9 it will light up but I have no Idea how to get the whole thing to work together.
So far I have eliminated the option of using a on/off type switch as that would mean I would have to push the switch 2 times to turn any given effect on or off...
Any help would be very much apreciated and once again I appologise for being so long winded. lol


New Member
As best I can tell from your description, a light on pin 9 and pin 2 would only be on when the drive is on. However, there is a fair chance that this would have the side effect of turning the drive off. Try it and see. If that doesn't work then you're going to need some transistors to switch the lights on.
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