your choice of 3pdt wiring and why?

[deadastronaut]

as the title says...i see so many different ways of wiring up a 3pdt, i'm just curious as to why you choose one particular way....

please link to wiring pic example of your choice..

[alanp]

I use the Mad Bean Standard Wiring 'cos that's how I got into pedal DIY -- I just wanted a LaVache, since I heard it was a good low gain pedal. (More'n a year later...)

[GoranP]

i use tagboardeffects offboard. it was the first one i found that made sense and it also grounds the board input while bypassed. not saying others don't, it's just the first one i found that did. i stuck to it because i had no reason to change, works like a charm.

[Buzz]

I use the GGG type wiring. Basically because my first pedal was a GGG kit.

I haven't had a problem with it so I haven't changed.

I'm interested in the Millenium bypass though. Save a bit of space and a buck or two.

[guitarmageddon]

I learned on BYOC kits, so use that method- and because it grounds the input in bypass.   The MBP is essentially the same, though it has an additional ground lug connection.
There's a good run-down of mechanical bypass switching and the reasoning behind it at BYOC here: http://byocelectronics.com/board/viewtopic.php?f=9&t=6525

[nomorebetts]

TonePad offboard wiring number 5.  And like other's here just because it was the first one I ever used.  Never had any problems like switch pops.
http://www.tonepad.com/project.asp?id=35

[CodeMonk]

Kind of a variation on this at Beavis : http://www.beavisaudio.com/techpages/StompboxWiring/
I ground the effect input when bypassed and sometime put the LED in the middle.

[R.G.]

A 3PDT is a DPDT with another section that can run an LED. See "The Technology of Bypasses" at Geofex for the variations of the actual bypassing part of the switching and the three ways to do this.

[GGBB]

The third pole adds circuit grounding capabilities to the three DPDT configurations RG points to.  There are four possible grounding options - none, input, ouput, and both:



There are more than four ways to wire the switch, but there are only four things they can do (assuming true bypass and the third pole is for grounding and LED).  I use the circuit input grounding above - nice and symmetrical - wiring lays out neatly.

[GoranP]

to add to the usefulness of this thread, does one care to comment on grounding input only vs grounding both input and output?

[kingswayguitar]

I learned on BYOC kits, so use that method- and because it grounds the input in bypass.   The MBP is essentially the same, though it has an additional ground lug connection.
There's a good run-down of mechanical bypass switching and the reasoning behind it at BYOC here: http://byocelectronics.com/board/viewtopic.php?f=9&t=6525

thank you kindly!

[peterg]

I use no circuit grounding shown on GGBB's post. What is the idea of grounding the circuit? To not have the components 'running' at all times?

[Vallhagen]

I do as the upper right one^^, "Circuit input grounded", at least for most of my builds. I did some thinking about this; "what is the best way", and i find it convenient and intuitive. And symmetrical. I have tried a few alternatives, but now i feel fairly stuck with that version.

One of my builds here: http://www.diystompboxes.com/smfforum/index.php?topic=102861.msg929656#msg929656

[cloudscapes]

I use no circuit grounding shown on GGBB's post. What is the idea of grounding the circuit? To not have the components 'running' at all times?

to avoid bypass pop. when ungrounded, a charge might slowly trickle up in the input/output bypass caps and you'll get DC offset. grounding helps prevent that.

[R.G.]

The third pole adds circuit grounding capabilities to the three DPDT configurations RG points to.  There are four possible grounding options - none, input, ouput, and both:

Actually, you can ground none, input, or output with a DPDT. You do have the ability to ground both with a 3PDT, as long as you wire the LED accordingly so you have the unused terminal connected to ground by an LED-grounding common in the third section.

Output grounded is not terribly useful, as most effects don't make enough noise when bypassed to couple through the air-path capacitance to the signal line which is, after all, completely unconnected.

Input grounded is useful for the minority of pedals that oscillate if their input is left open. In my experience, this is a band-aid for layout or wiring problems, but it may be needed for some pedals.

I'm not sure when grounding both input and output would be needed.

[darron]

http://www.dazatronyx.com/tech/what-is-true-bypass/


figure b:

[GGBB]

http://www.dazatronyx.com/tech/what-is-true-bypass/


figure b:

Unless my brain is not yet fully awake this morning - in figure B above - the center bottom lug does not need to be connected.  Connecting the center middle lug directly to the bottom left lug and to the output gives the same result and requires one less solder joint and one less length of jumper wire.

[darron]

http://www.dazatronyx.com/tech/what-is-true-bypass/


figure b:

Unless my brain is not yet fully awake this morning - in figure B above - the center bottom lug does not need to be connected.  Connecting the center middle lug directly to the bottom left lug and to the output gives the same result and requires one less solder joint and one less length of jumper wire.

That's true. It's not needed. It's there however so that in bypass mode only one pole is needed instead of two, making it theoretically quieter and more reliable.

[GGBB]

That's true. It's not needed. It's there however so that in bypass mode only one pole is needed instead of two, making it theoretically quieter and more reliable.

Look again - you still have this advantage with my adjustment:

[GGBB]

It's quite nice this one - with a couple of rearrangements you can get some very neat wiring:



Not functionally symmetrical, but I love the physical symmetry and how all the leads are on the outsides and especially that there's no lead coming off the center lug.