A True Bypass, Looper, Switcher Box will allow you to achieve "true bypass" by running your pedals though the send and return jacks. When the pedal is switched the signal will go straight from your guitar to your amp bypassing the pedal altogether. You can also chain your pedals together and bypass all of them at once. A basic one loop true bypass box consists of 4 mono jacks (input, output, send and return), 1 x 3pdt switch and a led to indicate when true bypass is on or off.
I added a 9 Volt DC power jack that powers the led, but it won't affect the tone. You can also leave out the led and the DC jack if you like. Wiring a 9 volt battery snap can be added, but I left it out of my wiring diagram.
You can also cascade the loops and have a bypass switch for each one of your pedals for the ultimate in true bypass switching.
A multi-box version can be wired by adding 2 more mono 1/4" jacks (send, return) another 3pdt switch, resistor and led, then wire from the first 3pdt switch (output jack "tip") "middle/center lug" to the (input jack "tip") "top left lug" of the 3pdt switch. Repeat this for each pedal you plan on adding to your pedal board. Now wire or daisy chain all the (send and return) jack "rings" together back to the input and output jacks.
Parts Needed (Basic Version):
- 1 x 1K Resistor (Note: Adjust value for LED Brightness)
- 1 x Loop Status indicator LED
- 1 x Mono quarter-inch jack (Input)
- 1 x Mono quarter-inch jack (Output)
- 1 x Mono quarter-inch jack (Loop Out)
- 1 x Mono quarter-inch jack (Loop In)
- 1 x DC Jack
- 1 x 3PDT foot switch
- 24 gauge stranded wire
- 1 x Enclosure
Also note it's a good idea to use a buffer "line driver" in front of your true bypass looper box to keep your tone alive. One of my favorites is the MC-401 Custom Audio Electronics Line Booster Driver by MXR. You can also build your own buffer/line driver right into the pedal, but that's out of the scope of this project. I attached a wiring diagram below for the IC Buffer if your feeling up to it.