Guide · Guitar electronics

The Greasebucket Circuit Guide

Fender's smarter tone control: how it cuts the highs without the mud, and how to wire one into your guitar.

By Montances Guitar Wiring6 min readWiring guide
Chapter 01 · The basics

What a Greasebucket is

Turn a normal tone knob down and your guitar gets dark, boomy and muddy. The Greasebucket is Fender's fix. It's a different tone circuit that cuts the highs but keeps the sound tight and usable, all the way down.

Fender fitted it to some of its guitars, including the Highway One series. It uses the same tone pot you already have, plus two small capacitors and a resistor. Nothing changes on the outside of the guitar.

Animation: as the tone knob turns down, a standard tone control loses its highs and turns boomy, while the Greasebucket rounds off the highs and keeps the low end tight01 23456 78910 TONESTANDARD TONEBassLo-mid MidHi-midTrebleTone on 10Boomy and muddy GREASEBUCKETBassLo-midMid Hi-midTrebleTone on 10Darker but still clear
Turn a standard tone knob down and the sound turns boomy and muddy. The Greasebucket rounds off the highs but keeps the low end tight.
What it replaces
The single tone capacitor on your tone pot
Parts
0.1µF GBC cap, 0.022µF or 0.047µF tone cap and a 4.7k resistor
On 10
Sounds the same as a standard tone control
Turned down
Smoother and less muddy, with more focus in the mids
Chapter 02 · How it works

How it works

A standard tone control is a pot and one capacitor to ground. As you turn down, the pot's resistance drops and the cap drains more and more treble to ground. On 0, only the lows are left, which is why it sounds muddy.

The Greasebucket changes three things:

  • The 0.1µF GBC cap sits across lug 3 and lug 2. As you turn down, it lets the treble go around the pot's resistance and into the rest of the circuit.
  • The tone cap (0.022µF or 0.047µF) does the actual tone cutting. It sends the highs to ground, just like a standard tone cap.
  • The 4.7k resistor sits between that cap and the grounded back of the tone pot. It stops the tone from ever cutting all the way, so the sound never turns to mud.
Schematic comparison: a standard tone control uses one capacitor from the wiper to ground, while the Greasebucket adds a 0.1µF cap across lugs 3 and 2, and a 0.022µF cap with a 4.7k resistor from lug 1 to groundSTANDARD TONEOne cap. Gets muddy on 0.SIGNAL 3210.022µF Turned to 0, it keeps cutting until only lows are left.GREASEBUCKETTwo caps and a resistor.SIGNAL 321GBC 0.1µF Tone cap4.7kThe 4.7k stops the cut before it gets muddy.
A standard tone control next to the Greasebucket. The extra cap and the 4.7k resistor keep the sound tight when you turn down.
Chapter 03 · Shopping list

Parts you need

PartValueMarkingWhere it goes
GBC cap0.1µF104Tone lug 3 to lug 2
Tone cap0.022µF or 0.047µF223 or 473Tone lug 1 to the resistor
Resistor4.7kYellow, violet, redTone cap to the back of the tone pot
Tone pot250k or 500kYour usual valueAs normal

The tone cap sets how dark the sound gets: 0.022µF is the classic Fender value, and 0.047µF goes darker, which suits many humbuckers.

Capacitors and resistors like these have no polarity, so either lead can go either way.

Chapter 04 · Wiring

Wiring a Greasebucket

Everything happens on the tone pot. Your volume pot stays wired as normal. The diagram shows the tone pot from the back with the lugs pointing down: lug 3 on the left, lug 2 in the middle and lug 1 on the right.

Greasebucket tone pot wiring, seen from the back: input to lug 3, a 0.1µF GBC cap across lugs 3 and 2, and a 0.022µF or 0.047µF tone cap plus 4.7k resistor from lug 1 to the back of the tone pot SEEN FROM THE BACK TINPUTFrom volume pot orpickup selector GBC CAP0.1µF (104)TONE CAP SOLDERED TO THEBACK OF THE TONE POT4.7k RESISTORyellow violet red0.022µF (223)-OR-0.047µF (473) Ground the tone pot casing to the volume pot casing
Greasebucket wiring on the tone pot, seen from the back.
  1. Input to lug 3Connect the wire from your volume pot or pickup selector to lug 3 of the tone pot.
  2. GBC cap across lug 3 and lug 2Solder the 0.1µF (104) cap between lug 3 and lug 2. Nothing else connects to lug 2.
  3. Tone cap on lug 1Solder one lead of the 0.022µF (223) or 0.047µF (473) tone cap to lug 1.
  4. Resistor to groundJoin the 4.7k resistor to the tone cap's other lead, and solder the resistor's free lead to the back of the tone pot.
Note

Make sure all metal parts are properly grounded. The tone pot's casing must be grounded to the back of the volume pot, or the resistor has no ground.

Chapter 05 · Two tone pots

Strats and two tone pots

On a Strat, or any guitar with two tone pots, each tone pot gets its own Greasebucket. Buy two sets of parts and wire each pot the same way.

Each tone pot's lug 3 gets its input from the selector switch, just like your stock wiring.

Chapter 06 · Best of both

Making it switchable

Some players love the Greasebucket on bridge and overdriven sounds but miss the classic dark neck tone of a standard tone control. You can have both. Swap the tone pot for a push-pull or push-push pot, and use its switch to choose between the Greasebucket and a standard tone cap.

Want a diagram for your exact setup? Request a custom diagram and we'll draw it for you.

Chapter 07 · Before you solder

Install tips

  1. Double check lug 1. On a stock tone pot, lug 1 is often soldered to the pot casing. Remove that link, or the Greasebucket won't work.
  2. Keep the parts tidy. Trim the leads short and keep the caps and resistor away from the pot casing and other lugs. Use heat shrink in a crowded cavity.
  3. Be quick with the iron. Tin each lug first and make each joint fast so you don't overheat the parts or the pot.
  4. Test before you close up. Plug in and sweep the tone knob. It should get darker without turning to mud, and sound normal on 10.
  5. Ground everything properly. Make sure all metal parts are grounded, and solder all your grounds to the back of the volume pot.

Rather not solder? Choose our pre-wired solderless kits, or let us do it with our wiring services.

Help

Frequently asked questions

What is a Greasebucket tone circuit?

It's a tone control designed by Fender. Instead of one capacitor, it uses two capacitors and a resistor. When you turn the tone down, it cuts the highs without letting the sound turn boomy or muddy.

How is it different from a standard tone control?

A standard tone control keeps cutting treble until mostly bass is left, so it gets muddy near 0. The Greasebucket's 4.7k resistor stops the cut before that point, and the extra 0.1µF cap shapes the sweep. You get a darker sound that stays clear and focused in the mids.

Does the Greasebucket add bass?

No. It's a passive circuit, so it can't boost anything. A standard tone control only seems to add bass because it takes the highs away. The Greasebucket takes less of that low-end weight with it, so it sounds tighter.

Does it change my tone with the knob on 10?

Very little. On 10 the full pot resistance sits in front of the caps, just like a standard tone control.

What parts do I need?

A 0.1µF GBC cap (marked 104), a 0.022µF (223) or 0.047µF (473) tone cap and a 4.7k resistor (yellow, violet, red). You need one set for each tone pot.

Can I use it with humbuckers?

Yes. Use the tone pot value that suits your pickups, usually 250k for single coils and 500k for humbuckers. Many players also pick the 0.047µF tone cap for humbuckers. The rest of the wiring stays the same.

Can I switch between a Greasebucket and a standard tone?

Yes. A push-pull pot or a mini toggle with a DPDT switch can swap between the two, so you get both sounds from one knob.

Tone without the mud

Get a Greasebucket harness

Get a pre-wired harness with the Greasebucket built in, or send us your setup and we'll wire it for you.

Shop pre-wired kitsAsk us a question

More wiring guides: see our treble bleed and push-pull guides, or request a custom diagram.