How To Do ADA Flanger LED Mod

Created 01/22/23

By Paul J. Marossy


Someone wanted me to add an LED to their re-issue ADA Flanger. It's not too difficult to do, but it's also not that easy to get the existing PCB mounted bypass switch off of the PCB without damaging it, and replacing it with a 3PDT switch. Below is an outline of what needs to be done, which applies to basically all of the ADA Flangers out there. On the older ADA Flangers, which are not true bypass, you'll need to use a DPDT switch in place of the stock SPDT switch.

Here is the patient before our surgical procedure.

The first thing that has to be done is to remove the existing DPDT footswitch from the circuit board. This will be the most difficult part to do. It can be extracted using desoldering braid or by using a good solder sucker. Be careful not to overheat the circuit board and damage it. This will give you a bigger headache! Take your time here on this step.

In order to use the standard blue 3PDT footswitch, you'll have to create some extensions to the solder lugs on the switch. Use something sturdy here but not too bulky. I used clippings from some 1N4001 diodes, which are pretty stout.
If done correctly, the switch will sit just above the circuit board when the footswitch is soldered onto the board. Pay attention to where the center of the switch is in relation to the circuit board. You'll want this to line up with the hole in the enclosure. The top inside nut needs to be 1-1/16" above the top of the PCB. You can also use the old footswitch as a guide.
Once the footswitch is soldered in place you can use the 3rd pole of the foot switch to switch your LED on/off. Here I am temporarily powering the LED using the outlet of the 15V regulator to test it before doing any drilling on the enclosure, to make sure it didn't have any problems with it making popping noises upon switching. Fortunately, I have not had that problem on any of the mods I have performed. I used a 10K resistor fo the blue LED. You'll need to use a resistor value that is appropriate for the LED that you want to use. The ground end of the LED can connect to ground near the footswitch (you can just see the end of the black wire in the picure).
When you're all done and everything is back together you should have something that looks similar to this. The location shown is really the only place to put it due to phyiscal constraints. The LED bezel I used here requires an 8.2mm hole. You can also use a 5/16" drill bit and very carefully use a round file to very slightly enlarge the hole until it firmly fits in the hole.

That's about all there is to it. If you take your time and are careful, you should be able to perform this mod, provided your skill level is up to the task.

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