The FAT-O-Caster (c) Users Manual & Guide
Edited 5/10/2010

What it is:

The FAT-O-Caster (c) is a three position ROTARY switch that expands the potential pickup combinations available in your Stratocaster or other "S-type" guitar. It installs where one of your old tone controls was. The FAT-O-Caster (c) does NOT replace your 5-way pickup selector switch - your 5-way still works just like it always did. The FAT-O-Caster (c) works in conjunction WITH the 5-way to give you new combinations. You lose a tone control, but gain a lot of tones!

The traditional Strat 5-way selector gives you only 5 of the seven parallel combinations possible, and no series connections. With the FAT-O-Caster (c), you can get all seven parallel combinations, PLUS two series settings, and a series/parallel setting,  for a total of TEN different pickup combinations.

That's a lot of tones!


Just put your old tone knob back on the FAT-O-Caster (c) switch, and your Strat looks completely stock!


Take off your pickguard.
To wire your lower tone as a "master" tone (like a Telecaster):

1. Move the lower tone control's lead from the mid pup’s lug on the tone side of the five-way over to the COMMON lug on the pups' side of the five-way.
2. Remove the lead from the center tone control at the neck pup’s lug on the tone side of the five-way.

3. Remove the ground leads from the back of the center tone pot.
4. Clip any jumpers between the center and lower tone pots.
5. Remove the center pot and mount the FAT-O in its place.

6. Run an insulated wire (this is the new ground lead) from the back of the volume pot to the lower tone pot,
leaving enough slack to rout it around the FAT-O.
7. Wire a tone capacitor with one leg on the center lug of the tone pot and one leg on the back of the tone pot (ground).


Unsolder the bridge and middle pup's GROUND ("-") leads from where they are currently in your guitar - usually the back of the volume pot. Solder them to the center lugs on the FAT-O-Caster (c) switch, making sure you get the BRIDGE PUP'S ground lead on lug “1” (the one with the string through it), and the middle pup's ground lead on lug "2" (next one clockwise, see drawing).

NOTE: Sometimes there is not enough wire on the ground leads to make it to the FAT-O, so just add on a little "tail" to the lead to get there. Be sure you insulate the solder joint on this "tail" to prevent contact with the pots or any other grounded surface in the control cavity - black electrical tape will work fine.

Three wire pups? MOST COMMONLY, two of the three leads are twisted together and soldered to ground. You will have to determine which wire of the two that goes to ground is actually the coil’s “-” lead, and which is the ground/shield drain. The easiest way to do this is to unsolder them from ground and separate them. With a multimeter set in the 20k ohm range, touch one probe to the pickup’s “+” lead, and then try the other probe on each of the other leads. The pickup’s “-” lead should show you the impedance reading for the pickup – typically between 6k and 8k for a Strat. The ground lead will show “open” – no resistance, no continuity. Solder the ground lead back to ground, and solder the pup’s “-” lead to the switch as instructed above.


The red lead is soldered to the 5-way switch. It goes on the third lug (would be the bridge lug) of the second pole of the selector switch (the side used to connect the tone pots). Please see the drawing.

The black lead is added to the neck pup's lug on the 5-way. It's the wire that will allow the ground (or "negative") lead of the bridge and middle pups to go back through the neck pup for the "Series" settings, and allows the neck pup's hot lead to go to the 5-way switch's output for the "Neck Always On" setting.

The bare wire is soldered to (any) ground.

Put your pickguard back on, and you're ready to rip!

How it works:

To reference the rest of these instructions,
we'll say that the pickup selections on the 5-way are numbered like this:
(1) = neck; (2) = neck and middle; (3) = middle; (4) = middle and bridge; (5) = bridge.

Basically, it re-routes the hot and ground leads of the pickups to different places in the guitar's curcuitry. Each of the three "clicks" connects the pickups' leads to a specific point in the guitar's wiring to get the desired combination of pickups and series/parallel wiring. These "clicks" - I call them "NOTCHES" - are named for how they route the pickups into the circuit.


NOTCH ONE (tone control on "10") is "NORMAL"
It is selected when you have the knob turned completely CLOCKWISE. The FAT-O-Caster (c) routes the Bridge pup's hot to the 5-way switch (where it would be, stock), and its ground to the guitar's ground, along with the Middle pup's ground.. Plain ol' Strat tones.

NOTCH TWO (tone control at "9") is "BRIDGE with NECK"
It is the first "click" as you turn the knob COUNTER-CLOCKWISE . This jumpers the NECK pup's output so that when you select the bridge pup, you get the neck pup as well. As you work the your Strat's 5-way pup selector switch, from neck to bridge, you will hear: (1) Neck alone; (2) Neck and Middle pups; (3) Middle; (4) Neck, Middle and Bridge; (5) Neck and Bridge.

Those LAST two tones are the tones EVERY Strat player sez they wish they had!

NOTCH THREE ( tone control at about "8") is "SERIES with NECK PICKUP"
When you select (5) on the 5-way, instead of just the Bridge pup you will get the Bridge and Neck pup in SERIES. In (3), you have the Middle and Neck pup in SERIES. In (4), you have both of those tones, parallel. In (2) and ( 1), you hear the Neck alone.

Pickups wired in series make the current flow through first one coil and then the other, effectively doubling the resistance/impeadence of the circuit. In a very real way, the Neck and Bridge (or Neck and Middle) coils become rather like a single big humbucker! This is usually characterised as a "fatter" sound than that produced by a single-coil pickup - though on your Strat, still plenty bright. It's a good way to add some "ooomph" that Bridge pickup's "lead" tone, and some "sass" to the middle pup..

Here's a link to a TONE CHART - where the heck ARE all these tones?

How the heck did I come up with this? The long story...

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