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MOD 4: TRUE BYPASS SWITCHING
Mod Type: Tonal
Difficulty Level: Medium
What You Need:
• Soldering iron
• Spare wire
• Insulation tape OR
• A 2-pole/double-throw
• Wire strippers
• Side cutters
• Short piece of tinned wire
• Wrench for footswitch nut
Our final mod is adding true-bypass switching to the same Vox wah from mods 2 and 3. Although we’re demonstrating this procedure on a wah, it can be applied to any pedal—as long as you can isolate the input- and output-socket wires, and the circuit input and output wires, and follow the instructions below.
I started writing the pros and cons of this mod but swiftly realized such an essay could fill a page or so. There’s plenty of info on it out there, so if you’re inclined to dive into the minutia, go forth and do your research. My take on it is that true-bypass switching is great—but you always need to make sure you have one pedal in your signal chain with a good, quality buffered bypass if you’re running long lengths of cable between your guitar, pedals, and amp. It all has to do with impedance. The low-impedance output of a good, buffered bypass pedal means you won’t get any high frequency loss using long cables.
So, let’s turn our Vox into a true-bypass device. First, let’s have a look at the existing footswitch—the black rectangular box connected to the brown, white, and blue wires (shown below).
The brown wire comes from the input socket, while the white wire goes to the output socket, and the blue wire comes from the circuit’s output. For those of you who have a Jim Dunlop Cry Baby wah, here’s a pic of its switch.
The color code for a Cry Baby is as follows: The green wire comes from the input socket, while the purple wire goes to the output socket, and the two blue wires connect to the circuit’s output.
Okay, back to our Vox wah.
To remove the old footswitch and install the true-bypass one:
1. Desolder all three wires.
2. Now look at the input socket.
See the two wires attached to the tip tag—the brown and green ones? The green wire is the audio-input lead for the wah circuit. Clip it so that it’s no longer connected to the tip tag.
3. Take a 3"-4" spare piece of wire, strip each end, twist the smaller wire strands at each end together to create a single, tightly formed lead, and tin both ends with solder.
4. Strip the end of the green wire that you clipped in step 2. Then twist the green wire together with the new piece of wire prepared in step 3. To solidify their connection, solder them together.
5. Insulate this cleverly extended bit of wiring by either trimming and applying an appropriate length of heatshrink tubing OR wrapping the exposed portion in insulation tape, as shown below.
6. Now let’s take a look at our new switch. Either a 2-pole/double-throw or 3-pole/double-throw will work. This one is a 3-pole/double-throw, but we’ll only use two of the three poles.
Note the nine tags on the bottom. (The piece of tinned bridging wire is on the table below the switch.)
7. Position your switch so it’s in the same orientation as the photo above right—that is, with three rows of three tags, with the holes facing you.
8. Solder a piece of the tinned wire to the bottom left and bottom middle tags.
9. Fantastic. Now remove the old footswitch and place the new footswitch in the vacated space.
10. Solder the brown wire (which is from the input socket) to the left-hand middle tag.
11. Solder the white wire (from the output socket) to the center tag.
12. Solder the blue wire (from the circuit output) to the middle top tag.
13. Solder the extended wire created in steps 3-5 above (which comes from the green circuit-input wire) to the left-hand top tag.
14. Marvelous—you now have true-bypass switching! Your tags should look like the pic below.
Go Forth and Modify
Although the four projects we’ve covered here are intended to be a simple introduction to the world of pedal modding, we’re confident that after you complete one or more and hear, see, or feel the difference it makes, you’ll be eager to do more. I recommend plugging into the giant super brain of the internet, which has a bounty of great mods available for the brave (of course, as with anything online, some are absolute tosh). As an initial port of call, I’d recommend geofex.com, fuzzcentral.ssguitar.com, and diystompboxes.com. Best of luck!