Wiring a 3PDT switch

All frequent questions on switching: true or not true bypass, transistor-based or mechanical.
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kalamaca
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Post by kalamaca »

Hi I've been following this pcb layout for the zvex fuzz factory ...
( https://i189.photobucket.com/albums/z93 ... ayout2.jpg )

and have put it onto a veroboard, but I'm using a 9 pin 3PDT, and I having trouble working it out. I've looked at beavis audio site and I'm trying to follow their instructions but i'm having trouble matching it up to the above pcb layout.

http://www.beavisaudio.com/techpages/StompboxWiring/

thanks

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IvIark
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Post by IvIark »

It's the blue wire going from the input socket sleeve to the top left hand terminal of the switch and then to the PCB
"If anyone is a 'genius' for putting jacks in such a pedal in the only spot where they could physically fit, then I assume I too am a genius for correctly inserting my legs into my pants this morning." - candletears7 - TGP

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kalamaca
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Post by kalamaca »

is the yellow wire going to the other ground?

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kalamaca
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Post by kalamaca »

Okay so reading more and more...

The connections from the switch should have

Input jack - Green Wire?
Output jack - Blue Wire
Effect Input - Green Wire?
Effect Output - Yellow wire?
Ground - Blue Wire?
Resistor to 9+ / LED? - ??

I'm confused because the beavis link shows the circuit with two ground conections?

Thanks in advance

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Post by IvIark »

Green wire from the input socket to the switch (bottom centre) is the main input wire
Yellow wire from switch (bottom right) to the PCB is the PCB input
Green wire from the PCB to the switch (top centre) is the PCB output
Blue wire from the switch (linked bottom left and top right) to the output socket is the main output wire

So basically in the off position (top centre and top left, along with the bottom centre and bottom left contacts are made) the input socket is routed straight to the output socket.

In the on position (top centre and top right, along with the bottom centre and bottom right contacts are made) the signal is routed through the PCB and then to the output socket.

If you're using an LED, just use the third pole of a 3PDT stomp for the LED (which will be the same as the wiring on the Beavis drawing using the three left hand terminals).

It's more confusing because the two diagrams you're looking at are rotated 90º from each other, but they are also using a different type of true bypass wiring anyway which adds to the confusion. If you stick to the way it is shown in the Fuzz Factory scheme it would be preferable by some people because the PCB output is grounded when bypassed.
"If anyone is a 'genius' for putting jacks in such a pedal in the only spot where they could physically fit, then I assume I too am a genius for correctly inserting my legs into my pants this morning." - candletears7 - TGP

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kalamaca
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Post by kalamaca »

thank you,

so wiring this up using a 9pin swtich...

should i follow the layout and leave the bottom 3 pins of the 3dpt unconnected to anything

or should it be like in my picture i've made
https://i181.photobucket.com/albums/x10 ... a/3pdt.jpg

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Post by IvIark »

That diagram won't work. In the on position the +9V of the battery is taken straight to gound, or have you just missed off an LED and resistor?

Personally I'd do it like the Fuzz Factory scheme but with the third pole being used solely for the LED. Bear in mind that your diagram is also rotated 90º from the switch shown in the FF scheme and so where yours is shown with the contacts vertically like this:

1 - 4 - 7
2 - 5 - 8
3 - 6 - 9

The setup in the FF scheme has the contacts horizontal like this (omitting the third pole)

4 - 5 - 6
7 - 8 - 9

All the above assumes:

1, 2 and 3 are pole 1
4, 5 and 6 are pole 2
7, 8 and 9 are pole 3

2, 5 and 8 are the common connections for their respective poles in both cases.
"If anyone is a 'genius' for putting jacks in such a pedal in the only spot where they could physically fit, then I assume I too am a genius for correctly inserting my legs into my pants this morning." - candletears7 - TGP

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