3PDT foot switch wiring, many different ways.....

[trancedental]

I replaced the faulty foot switch in my Vox V810 Valve Tone pedal which is a 808 type pedal, it works fine but the footswitch still pops when turned on/off. Maybe the layout I used was not right & causes the popping.

There are a lot of different ways to do wire these up,so I had a look at my SRB 808 pedal & it is wired exactly the same as this attached layout diagram.

http://rudemechanicaloz.files.wordpr...ypass-diag.jpg

Seems all the pedals with 3PDT true bypass wiring that I currently have are using different layouts to each other?

I think I'll give this SRB switch layout a try but would like to know what layouts everyone else here is using for their foot switch wiring & why some are perhaps better than others?

[tjk3052]

That switch wiring is fine. Sounds like you need a pull down resistor. Pull down resistors are a large value (~1-2Mohm) and are connected from the PCB input to ground. Sometimes one is needed at the output as well. They discharge the input/output caps, which is what's causing the pop.

[trancedental]

I've put another 3PDT switch in, with the new wiring layout, it works fine without any popping, BUT the LED light comes on when the effect is bypassed & turns OFF when the effect is active!!!

I'm thinking this pedal has a weird LED circuit, because the LED itself can't be in the wrong way or it wouldn't work would it? They only work with one polarity from my limited knowledge

[limbe]

If the LED worked when it was wired as in the diagram you supplied,it will work with another 3DPDT switch if the switch is wired right.
My personal preference when wiring those switches,is to treat 2 sections as a DPDT switch for the signal wiring and the third section as a SPDT (Single pole switch) for the LED.It sounds as if your LED is connected to ground when the pedal is "off" instead of "on".

[pt1911]

Here is the switch wiring i use. It is the simplest one i have found. I don't understand when some people use such complex wiring systems. Hope it helps.



Sent from my SCH-I405 using TDPRI

[limbe]

trancedetal! In your photo,I can´t see any wire that is connected to lug 1!
According to your schematic the resistor from the LED should be connected to that lug.
Is it now soldered to that lug? (I am aware that this could be a stupid question.)

[steve440]

This is the one I use. The benefit is when bypassed the input to the effect is grounded. This will get rid of any leakage from your input capacitor and will help to decrease any pops when engaged. The benefit is more noticable on higher gain effects as the pop is normally amplified.

[limbe]

Steve.The wiring you use and the wiring in the diagram trancedental posted are both correct and will do exactly the same thing.Ground the PCB-boards input in bypass mode.The difference is in the photo trancedental posted.There are only 5 wires leaving the switch.There should be 6 as in your and his diagram to make it work as intended.
Where is the lead coming from the resistor that is connected to the negative side of the LED?

[steve440]

Limbe

Solder it onto the board on the positive side.

Steve

[limbe]

I guess I was very unclear this time.I see you are trying to help me Steve.
I know how to wire the switch and so do you.
It is trancedental who has a problem. Your wiring diagram is of course correct.
trancedentals diagram is also correct.(follow his link in the first post.)
On the photo of the switch though,there is 1 wire missing.The one that should be connected to lug 1 on the switch.
If trancedental has corrected the wiring after the photo was taken ,I don´t know.

[trancedental]

Thanks for the help & responses.

I've not had the chance to get back to this but have worked out that the Vox V810 has a different way of wiring up the bypass / LED switch. I seem to remember some article on the net somewhere saying it was similar to a RAT 2 pedal which has a 2PDT switch fitted, which was the same type as the faulty one I replaced in my Vox originally. There's a main PCB & a daughterboard for the LED with headers connecting them up with the input / output / foot switch.

Here's some schematics http://www.sugardas.lt/~igoramps/vox...schematics.gif

Another one http://romzin.comxa.com/data/img/elec/vox_v810.jpg

Maybe this is why it works the wrong way around? And could explain the noise when turing off & on. There's a transistor Q4 (2SC1815?) involved in the bypass circuit on both schematics.

It could be an idea to just get a jumper wire from the 9V circuit & add a resistor & LED bypassing the original?

[fender09]

Maybe you guys can help me out. I found this 7 fuzz on the web and decided to build it. I used the schematic/diagram below and the wiring for the 3pdt footswitch.

My goal was to not use a 9v battery and just use a plug adapter and I also added an led w built in resistor. How should it be wired?

I did the 3pdt wiring like my picture and placed the shield of the plug adapter where the schem says +9v then grounded the tip of the plug; the third solder place one the plug I didn't use. Then I did TIP from IN jack to 3pdt and IN on schem to 3pdt. Then TIP from out jack to 3pdt and OUT on schem (which is middle of vol pot) to 3pdt.

Something isn't right. The LED works as it switches but absolutely no sound comes out.

Maybe the schem is just screwed and I picked a bad one to build...idk.

[steve440]

trancedental

Sorry, haven't really help much so far. The pedals has the old millenium type bypass as you say similar to the rat. You only need a dpdt switch for this or you can use just 2 poles of your 3 pole switch

Ignore all 3pdt true bypass switching info you may have, and follow this:



Ignore the vero part it's not important

Steve

[steve440]

Fender 09

Do you have a multi meter??

Steve

[trancedental]

Thanks Fender

I'm a bit clueless with pedals as you may have noticed, this is the first one I've messed about with, I've built LA2A / 1176, compressors, Neve Mic Pres / EQ's & a Vibroverb but never a pedal LOL!

I've already wrecked two switches, I've just jigged a LED off the 9V & it works OK. I'll finish it that way now.

I'm going to keep things simple, I've got a hunch that the original bypass circuit is causing the popping all along. Although the original DPDT switch was faulty so I had to replace it.

[fender09]

I have a mulit-meter! What needs to be done?

Thanks!

[limbe]

I am very sorry.I took for granted that the photo you posted was a picture of the original switch.I should have smelled a RAT.As long as I am here I want to ask a question.
If the switch is the only thing that has been removed,why not use the original wiring shown in the correct Russian schematic? http://www.sugardas.lt/~igoramps/vox...schematics.gif

[fender09]

Steve 440

What do I need to measure with my meter?

[steve440]

Make sure you've got continuity on your signal into/out of the board
Check you have 9v into the board
Make sure you have ground continuity between board and enclosure with input jack plugged in
If you have 9v on board +&- then measure the 3 pins of each transistor to ground. You should have something like this (your results may vary slightly)


Collector 1.2-8v
Base >1v
Emitter - milivolts

A pictur or 2 of the guts would help if possible

Steve

[trancedental]

Originally Posted by limbe

I am very sorry.I took for granted that the photo you posted was a picture of the original switch.I should have smelled a RAT.As long as I am here I want to ask a question.
If the switch is the only thing that has been removed,why not use the original wiring shown in the correct Russian schematic? http://www.sugardas.lt/~igoramps/vox...schematics.gif

I replaced the original which was faulty, sometimes it didn't operate at all & when it did it usually popped!

First I tried a 3PDT with the LED bottom of the third row, worked OK but still popped, I then wrecked that one trying different layouts trying to solve the popping problem.

The next 3PDT was wired up after I started this thread. I'm 100% sure that the LED & circuit causes the popping problem, plus the LED cable is now to short to reach to the switch............!!!

So I just done the job another way