MOD 4: TRUE BYPASS SWITCHING
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
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
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
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
. Best of luck!