How To Build A True Bypass Loop Pedal

How To Build A True Bypass Loop Pedal

If you’ve ever wanted to build a simple true bypass loop pedal then it’s not as hard as you think!


We’ll also discover how to add tuner out and master bypass.


While you can buy something simple like Radial BigShot EFX True Bypass Effects Loop Switcher. Or even a more complex looper like the JOYO PXL4.


However, building exactly what you need is actually quite simple when you know what you’re doing.



What You Need

You need a few tools including a soldering iron and solder, wire cutters. If you have a vice, then that will help to speed up the process. Also, try to find a piece of wood to work on.


All of these true bypass loop pedals have 5 basic components: Mono jack socket(s), 2.1mm DC power socket, 3PDT footswitch, 5mm LED, LED holder and 4.1k resistor [you will need to match this to your LED]. You’ll also need wire and an enclosure. You can pick all of these up fairly cheaply and easily.


I recommend buying a pre-drilled enclosure, especially if you’re building more than one loop.



Single True Bypass Loop Pedal

Single True Bypass Loop Pedal


This is the most basic idea and the best starting point. You’ll need 1 x 3PDT footswitch, 4 x Mono Jack sockets, 1 x LED, 1 x Resistor, 1 x 2.1 mm DC power socket and wire.


Once you’ve got it all wired together, then you’ll need an enclosure and an LED socket. Again, start with this, as the more complex versions of this circuit are just this one multiplied.



Double True Bypass Loop Pedal

Double True Bypass Loop Pedal


This double looper is just two singles joined together.  As you can see the output of the first loop feeds the second.


You’ll need 2 x 3PDT footswitches, 6 x Mono Jack sockets, 2 x LED, 2 x Resistor, 1 x 2.1 mm DC power socket and wire. Also, you’ll need an enclosure and 2 x LED socket.



Double True Bypass Loop Pedal with Tuner Out/Mute

Double True Bypass Loop Pedal with Tuner Out Mute


This is just a triple looper with the return of the first loop missing! You can use the tuner loop as a mute for changing guitars or for feeding a tuner so you can silently tune. 


You’ll need 3 x 3PDT footswitches, 7 x Mono Jack sockets, 3 x LED, 3 x Resistor, 1 x 2.1 mm DC power socket and wire. Also, you’ll need an enclosure and 3 x LED socket.



Four True Bypass Loop Pedal with Master Bypass

Four True Bypass Loop Pedal with Master Bypass


This took me a while to figure out. I remember trying to kill time on a flight by trying to solve how to add a master bypass.


Basically, the 4 loops sit within one master loop which allows for them to be bypassed. It’s a really cool idea and super useful if you’re running a few different guitar fx pedals.


You’ll need 5 x 3PDT footswitches, 10 x Mono Jack sockets, 5 x LED, 5 x Resistor, 1 x 2.1 mm DC power socket and wire. Also, you’ll need an enclosure and 5 x LED socket.



Four True Bypass Loop Pedal with Master Bypass and Tuner Out/Mute

Four True Bypass Loop Pedal with Master Bypass and Tuner Out Mute

This is highly complex and I’d recommend building each loop on a breadboard. Once you’ve got it working, then build and add the next one. You’ll see that I’ve placed the tuner out before the master bypass.


You can use the master bypass function to preset pedal combinations, which you can bring in and out by hitting the master switch.


You’ll need 6 x 3PDT footswitches, 11 x Mono Jack sockets, 6 x LED, 6 x Resistor, 1 x 2.1 mm DC power socket and wire. Also, you’ll need 6 x LED socket and a super large/custom enclosure.



Sucess stories!

Since writing this post a few years ago, I’ve gotten a few emails from people who’ve tried to build one of the above or their own modified version of it. I’d love to hear from you if you have. So , here are some reader’s pictures of their success. Enjoy!


reader true bypass looper


  • Hi Ashley,
    awesome job…I’m intending to convert a Blackstar amp selector pedal into a 3 loop bypass pedal, so super useful.
    One thing…can’t find what the power source rating should be for your build (9v, 12v,?)

    • Ashley Saunders says:

      Typically 9v (as per the standard guitar pedals) but depends on the LEDs and resistors. Glad you found it useful!

  • Jason says:

    This is super helpful! Thank you!
    Hope you don’t mind a question: Is the power just for the light? Will the switch work without power (minus LED and resister)?

    • Ashley Saunders says:

      Thanks! Always happy to help! Yes, your right, it only needs power for the LED(s). So you could build one without power, LED and resistor.

  • Mike says:

    Any particular resistor value? Looks pretty straight forward. I may have missed that value in the article. Can’t wait to try it.

    • Ashley Saunders says:

      Hi Mike, really depends on the LED you’re using. I believe typically you could use a 100K resistor with a 5mm LED. Hope that helps!

  • Mark Morrison says:

    Hi Ashley!

    Thanks so much for this info! I built a 5 channel switcher (1 tuner/mute). Used the new switches with LED rings built in and it looks great. Also found a guy on ebay that makes colored nylon washers so I could color code the jacks with the LEDs. Hit a snag with an all metal DC jack (I had handy) until I realized it was not made for center negative and was grounding power to the box. Switched to a plastic jack and it’s working great. Experimented with resistor values for my desired brightness and discovered the green LED was brighter so I needed a higher value for that one to match the others. Now I just need to rewire the pedalboard as things have shifted a bit. Love to send a picture. Looks awesome and I couldn’t have done it without you.

    Thanks again,

    • Ashley Saunders says:

      Mark, Thanks so much for this. I’d love to see a picture (happy to add it to the article!). Hope you have a cleaner sounding guitar rig thanks to the looper! Ashley

  • Mike says:

    Do these diagrams configuration ground the input.? To eliminate signal bleed over into the bypass.?? Think I read something about that some where.? I’m going to diy a 6 loop switcher without any master bypass or tuner and I’m trying to get my head on straight before I start..thanks.

    • Ashley Saunders says:

      You need to connect all the grounds to a single point. Good luck, please send me a photo when you’ve built your true bypass looper! 🙂

  • Ken Gibson says:

    What resistor value would you recommend for 3mm 12v leds thanks

    • Ashley Saunders says:


      I’d try a 390 ohm resistor. If that’s not bright enough then try 340 ohm or 440 ohm if too bright. But 390 should be perfect. Let me know how you get on!

  • Arthur says:

    Hi Ashley,

    I followed your example for a double true bypass looper and run a build of it that actually works great when I have all jacks connected to something, it is practically noiseless, but if I did not connect one of the loops it produces a loud and crazy hum, it doesn’t matter which of the lopps are not in use if I Don connect something also just a patch cord to the loop it really hums but if just connect a pedal or a patch on the empty chain it works great. Maybe it is an expected behaviour but I am curious about why this happens.

    Thank you a lot!

    • Ashley Saunders says:

      Hey Arthur, That’s really cool. Thanks for letting me know that you enjoyed building and using a true bypass looper. I think, Arthur that you might have a ground issue. Are all the grounds connected together? Also, you can try adding a ground wire to the enclosure (so long as it’s metal!). Please Let me know if that works?!

  • Arthur says:

    Ashley, you are right it was a grounding issue and a really silly actually, I decided to use closed 6.35 jacks, like used on pcb boards the ground issue is that because I accidentally drill my stomp box to close to the edges for the input A and for the output B, I decided to turned them inner side and I soldered the connection to previos – next ground on the chain in a distinct ground pin of the jack , this kind of jacks have 2 ground pins that only closes the ground line when the jack is in use, and that interruption in the ground line was the origin of the hum, I just bridged them and right now is totally noiseless.

    Thanks a lot for the help!

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