Can I add a bypass LED to a Cry Baby?

[bcalla]

A friend of mine asked me if I could install an LED in his Cry Baby.  Seems he played part / all of a set with the wah engaged and didn't realize it until the next break.  He knew something was off but in the heat of performing couldn't focus on solving the problem.  Now it makes sense to have an LED to indicate when the pedal is engaged.

I figured it would be a piece of cake – either replace the DPDT stomp with a 3PDT, or hook a millennium bypass up to the unused lug of the DPDT.

However, he sent me pictures of the switch and it doesn't make any sense to me.  The 4 wires from the board are all attached to the same side of the DPDT switch, with 2 wires connected to one of the corner lugs.  And those 3 wired lugs are each jumpered to the matching unwired lug on the other side. I have no clue what's going on here.  Anyone have any suggestions?

[nate77]

I've done true bypass/led mods to a few crybaby wahs, and it's pretty straight forward. You'll new to find the most appropriate place to set the led so it's visible and doesn't interfere with the other comp

[nate77]

Oops. Premature post ! .....components. I'd be lying if I told you I had never left mine on unaware. Good luck

[CodeMonk]

Have a look here :
http://www.diyguitarist.com/DIYStompboxes/WahTrueBypass.htm

And this : http://www.diyguitarist.com/PDF_Files/WahTrueBypass.pdf

[bcalla]

This is what I'm dealing with:




I am at a total loss how to proceed.  Is anyone familiar with this?

[Seljer]

If that's a DPDT switch they've just shorted the two halves together and are using it as an SPDT (probably cheaper to buy mass quantities of DPDT switches). Its not true bypass at all. It's probably taking the clean signal from the first buffer on the board.

If you want to use the millenium bypass then you'll need to convert it to true bypass, that requires cutting a trace at the input jack and running an extra wire to the switch for the unbuffered signal. Here are some instruction which appear to have your revision of the wah pictured http://stinkfoot.se/archives/546



I installed a LED on my wah on the right side with a little plastic bezel. I scuffed up the surface of the LED with sandpaper so it's diffuse and viewable from all directions.

[bcalla]

Thanks for the answers.  My goal is not necessarily true bypass, it is to light an LED to show that the pedal is engaged.

I thought that the switch might just be a DPDT, but I don't see why they would bother to connect the 2 sides.  If that's what is going on, can I just cut those connections and use the other side of the switch to engage the LED?  Has anyone done this?

The reason I want to get my questions answered is that I don't actually have the pedal to experiment on.  I will be doing this for my friend the next time I am over his house, probably in 2 weeks.  So I want to be prepared with everything I will need.

[Seljer]

As a measure of redundancy and perhaps improved mechanical strength of the so joint I suppose

If you don't need true bypass then, yes, just do as you proposed, just cut the middle bits and use half of the switch for the LED.

[PRR]

This is trivial. They needed a SPDT switch, they used a DPDT switch.

To annoy you, they ran wires through both poles.

Snip the jumpers from one side to the other. Audio will switch fine on the far side.

Now you have an un-used SPDT section. The LED only needs a SPST.



+9V, through resistor (so switch-shorts don't burn the battery), to middle lug. LED from middle lug to ground. If LED don't light, reverse it. If the switch lights when "off", put the LED lead on the other end lug.

5K or 10K, whatever is handy, is a suitable trial value for resistor.

[bcalla]

Thanks for confirming that.  This will make my friend very happy.

[deadastronaut]

i'm doing the same as Paul suggested with my crybaby...i quite like the buffered bypass...

nice simple solution/mod.