In my previous column, we began a two-part series on
Fender’s Delta Tone system,
which includes “no-load” pots.
After introducing the Delta Tone
in 1997, Fender made it a feature of the American Standard
Stratocaster, and the system
is still in use today. For a full
description of the Delta Tone
system, check out the January
2011 installment of Mod Garage
on premierguitar.com/jan2011.
Now, let’s take a closer look
at no-load pots. Visually, it’s
easy to identify a no-load pot,
because of the detent dimple on
the back of its enclosure. This is
the mechanical spot where the
pot clicks and goes completely
open, removing itself from the
circuit. Other than having this
dimple, a no-load pot looks like
any other guitar potentiometer.
The CTS no-load pots that are available from
Fender aren’t very expensive, but if you like
the tone pot you already have and don’t want
to replace it, it’s not difficult to mod it to
no-load specs—that’s assuming you can live
without the detent function.
pliers, start this operation by
bending the pot’s case tabs open.
Next, remove the metal housing
and lift out the carbon wiper
tray with the soldering lugs.
Place it in front of you exactly
as shown in the photo shown
here. Though your potentiometer might be a little different, it
should look similar to this one.
Now take a sharp razor
blade, X-ACTO knife, drill bit,
Dremel tool, or a small needle
file and cut the trace, right at
the red line shown in the photo.
Personally, I like to use a special
file made for guitar nuts for this
work, but you can use whatever you have at hand. Scrape
off approximately 1/8" of the
carbon and clean this area with
a dust brush or a similar tool.
That’s it.
Next, reassemble the pot
and use the needle-nose pliers
to push back each of the four
case tabs. Reinstall the pot on
the pickguard and resolder the
wires. Voilà! With the pot fully
opened, it will remove itself
from the circuit. Now you have
a no-load pot without any additional costs . . . but without the
detent feature.
A side note: You might read
that covering that area on the
carbon wiper tray with nail
polish will do the same trick as
scraping off 1/8" of carbon. I
don’t recommend this, because
depending on the pot, the polish may not stick to the carbon
taper. The “surgical method”
outlined here is better.
To test your no-load pot,
turn your pot so that the shaft
is facing down and the lugs
are facing up, and connect one
lead of your digital multimeter
(DMM) to the middle lug of the
pot, and the other lead to the
right lug. Next, set your DMM
to resistance. With the pot
turned all the way clockwise to
10, you should receive an open
or “no reading.” If you turn
•;Take;the;pot;apart;as
described in the column.
•;Use;a;punch;to;make;an
inward indentation in the
metal casing.
•;Put;the;nylon;rotor;back;in
the casing and position it so
it covers the indentation.
•;Use;Blu-Tack;putty;adhesive;to
hold the nylon piece in place.
•;Apply;a;40W;soldering;iron;to
the indentation. Hold the iron
against the casing for a while
to build up heat—like when
you’re first learning how to solder wires to the pot casing.
•;Use;a;sharp;knife;to;scrape;off
the melted nylon from around
the indentation.
•;Reassemble;the;pot.
The DIY Detent
If you’re making your own
no-load pot, as described in
this column, and you simply
can’t live without the detent
function, it’s possible to create a detent in a standard
pot. A customer sent me this
procedure and it really works,
but it is a bit tricky, so you
should practice this on some
cheap or worn-out pots before
trying it on your nice new pot.
Considering the low cost of
no-load pots that already have
a detent, I doubt it’s worth the
time. But I want to satisfy the
most hardcore DIY folks, so
here’s the process:
the pot counter-clockwise to 9
or lower, the pot will function
normally, and you should see
readings that are close to the pot
value and that decrease as you
roll back toward 0.
Stay tuned for more Strat
mods in the coming months.
Next time, we’ll talk about the
Fender “Greasebucket” tone
control. Meanwhile, keep mod-ding!
Making your own no-load pot involves cutting the trace on the carbon
wiper tray. The red line indicates the area where you’ll scrape off approximately 1/8" of the conductive carbon.
DIRK WACKER lives in
Germany and is fascinated
by anything related to old
Fender guitars and amps.
He plays country, rocka-
billy, and surf music in two
bands, works regularly as a
session musician for a local studio, and writes
for several guitar mags. He’s also a hardcore
guitar and amp DIY-er who runs an extensive
website— singlecoil.com—on the subject.
