Hooking an LED up to a DPDT Switch

[Guybrush]

Hey all

I'm currently putting together a circuit which requires a DPDT footswitch rather than the normal 3PDT.

Would anyone be kind enough to spell out how to connect an LED to this? You know the standard LED is on when pedal is engaged, off when disengaged. I've not used DPDT switches before so I'm not familiar with how to do it.

Here's a pic of how the build odc says to wire the switch to the board. I'd be grately appreciative if someone could add the LED connections to it.




Also, will it be possible to hook the circuit up to a test rig which uses a 3pdt so I can make sure the board is all working before connecting the jacks and foot switch?

Thanks guys

[drolo]

Since all the pins of the switch are used already there is no place to add a LED. Unless you could use one of the middle pins for it without affecting the actual circuit. But We would have to see the rest of the schematic for that. 

[mgwhit]

Since all the pins of the switch are used already there is no place to add a LED. Unless you could use one of the middle pins for it without affecting the actual circuit. But We would have to see the rest of the schematic for that. 

Drolo is right.  As long as as you want to power the LED at the same time that you power a given FETSW it probably won't be complicated to attach the same solder lug to the CLR and the anode of the LED (in series).  Seeing a schematic would help.

But do you really have to use a DPDT?  Every 3PDT can be thought of as a DPDT plus a linked SPDT.  As long as there aren't physical constraints (space?) against using a 3PDT, you could use 2 poles as your DPDT and use the third pole to ground your LED.  That's essentially what all the standard true-bypass 3PDT wiring schemes do, they just wire the non-LED poles differently.

[Guybrush]

Ahh ok.
It's Deadastronaut's Chasm reverb.


I've just found that few other Madbeaner's have built this and incorporated an LED with the DPDT so it must be possible.

Here is a pic of mmlee's build where you can see the LED. It looks like he's used the method you both mentioned.



Thanks for the help.

[mgwhit]

Drolo is right.  As long as as you want to power the LED at the same time that you power a given FETSW it probably won't be complicated to attach the same solder lug to the CLR and the anode of the LED (in series).

That looks like exactly what is happening in the photo.

But do you really have to use a DPDT?  Every 3PDT can be thought of as a DPDT plus a linked SPDT.  As long as there aren't physical constraints (space?) against using a 3PDT, you could use 2 poles as your DPDT and use the third pole to ground your LED.  That's essentially what all the standard true-bypass 3PDT wiring schemes do, they just wire the non-LED poles differently.

Since you don't have space constraints, you could do this, too.

[flanagan0718]

This is how Jon (Midwayfair) did it with his Hamlet Delay. I have tried it and it does work. The Hamlet was designed for "with Tails" function. It looks like the Chasm is designed the same way. I would try this method. It should work fine.

[Guybrush]

Wonderful. Thank you!

[mmlee]

Ha, wasn't expecting to see my build pop up. Just do what I did in that pic, I've had no issues and I was following the schematic to do the build rather than build doc so I must have done it for a reason.

[davent]

Millenium II works well, true bypass and led switching with a DPDT switch.

http://www.geofex.com/article_folders/millenium/millen.htm

[mmlee]

I like the millennium bypass, not so much in a chasm though, no more tails....

[upthepunxxx]

Thats what I was going to suggest.

http://tagboardeffects.blogspot.com/2014/01/millennium-bypass-2.html

Millenium II works well, true bypass and led switching with a DPDT switch.

http://www.geofex.com/article_folders/millenium/millen.htm

[flanagan0718]

Not to offend anyone but I think you want to stay away from the Millenium bypass stuff. It is a great option for other builds but you loose the tails if you use it. In some effects not having TB is a benefit. This build would benefit from the tails option IMO.


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[davent]

I assumed the Chasm was true bypass, trying to remember how i got around tails in my Echo Base which i did use the millenium in.

[Guybrush]

Ha, wasn't expecting to see my build pop up. Just do what I did in that pic, I've had no issues and I was following the schematic to do the build rather than build doc so I must have done it for a reason.

Sorry mate I was going to message you and ask about it but thought it better to use the Tech Help board so that the answer's can be seen by others with the same issue in the future.

I think you're method seems the simplest so I'll give it a shot.

Thanks for all the help. It is greatly appreciated.

[upthepunxxx]

No offense taken hombre! Didn't fully realize that's what  the build was. Also never built any verb or delay effects before, so that's good to know! Thanks dude!

Not to offend anyone but I think you want to stay away from the Millenium bypass stuff. It is a great option for other builds but you loose the tails if you use it. In some effects not having TB is a benefit. This build would benefit from the tails option IMO.


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