Fender Stratocaster volume and tone

The knobs

Volume

Turning it down puts the top part of the track in series with the pickups. That damps their resonant peak before the level drops much.

Tone 1

Works in the neck and neck + middle positions. Turned down, the shared cap sits across the pickups through the pot and the peak moves down.

Tone 2

Works in the three middle positions, and on the bridge with the option on.

Switch positions

Neck

The neck pickup alone, with Tone 1.

Neck + middle

Neck and middle in parallel. Both tone pots are connected, so each works on both pickups, and together they load the pickups slightly more than either alone.

Middle

The middle pickup alone, with Tone 2.

Middle + bridge

Middle and bridge in parallel, with Tone 2 on both.

Bridge

The bridge pickup alone. The switch leaves the tone pots out, so neither tone control works here unless the Tone 2 on bridge option is on.

Parts

Neck

The neck pickup’s own voltage, from the string moving in the magnet’s field near the neck. Each pickup’s response is measured against this voltage.

Coil R

5.94 kΩ, The neck pickup coil’s resistance, measured on a vintage-style Strat single coil (5.94 kΩ DC, 2.96 H at 1 kHz).

Coil L

2.96 H, The neck pickup coil’s inductance, measured on a vintage-style Strat single coil (5.94 kΩ DC, 2.96 H at 1 kHz).

Winding C

120 pF, The capacitance between the neck coil’s turns, across its output. A typical figure, not a measurement.

Middle

The middle pickup’s own voltage, from the string moving in the magnet’s field between the other two. Each pickup’s response is measured against this voltage.

Coil R

5.94 kΩ, The middle pickup coil’s resistance, measured on a vintage-style Strat single coil (5.94 kΩ DC, 2.96 H at 1 kHz).

Coil L

2.96 H, The middle pickup coil’s inductance, measured on a vintage-style Strat single coil (5.94 kΩ DC, 2.96 H at 1 kHz).

Winding C

120 pF, The capacitance between the middle coil’s turns, across its output. A typical figure, not a measurement.

Bridge

The bridge pickup’s own voltage, from the string moving in the magnet’s field near the bridge. Each pickup’s response is measured against this voltage.

Coil R

5.94 kΩ, The bridge pickup coil’s resistance, measured on a vintage-style Strat single coil (5.94 kΩ DC, 2.96 H at 1 kHz).

Coil L

2.96 H, The bridge pickup coil’s inductance, measured on a vintage-style Strat single coil (5.94 kΩ DC, 2.96 H at 1 kHz).

Winding C

120 pF, The capacitance between the bridge coil’s turns, across its output. A typical figure, not a measurement.

Volume

250 kΩ, Volume, 250 kΩ audio taper, fed from the switch. Even at full it loads the pickups with its whole track.

Tone 1

250 kΩ, Tone 1, 250 kΩ audio taper, used as a variable resistor in series with the tone cap. The switch’s second pole connects it in the neck positions.

Tone 2

250 kΩ, Tone 2, 250 kΩ audio taper. It’s connected in the middle positions, and in the bridge position with the option on.

Tone cap

47 nF, One tone cap shared by both tone pots. Fender has used everything from 22 nF to 100 nF over the years.

Bleed cap

1 nF, Treble bleed cap across the volume pot’s top half. It keeps the treble as the volume comes down.

Bleed R

150 kΩ, Sits in parallel with the bleed cap so the treble lift doesn’t get too big at low volume settings.

Pickups and load

Each pickup is a voltage behind its coil’s resistance, inductance and winding capacitance. All three use the same measured single-coil values. The middle pickup is in phase with the others, as on most recent Strats, where it’s reverse wound to cancel hum. With two pickups on, each one loads the other through its coil. Without the string model, the graph adds them as if their voltages were equal and in phase. On a real string each harmonic reaches the two pickups at a different strength and sign, and that’s what makes the in-between positions sound the way they do. The string model uses a 25.5 in scale, with the pickups measured from the bridge saddle at about neck 6.3 in, middle 4 in, bridge 2 in under the low E to 1.5 in under the high E (measured by Swell Amplification, approximate). The neck pickup sits under where a 24th fret would be. The bridge pickup is slanted, with its treble end closer to the saddles. Harmonic n reaches a pickup x from the saddle scaled by sin(nπx/L), with L the string length, so a pickup near a node barely picks that harmonic up, and two pickups can cancel it. The string is ideal and each pickup is a point under it (a real pickup’s wider window softens the top harmonics). The slant is assumed to be even across the strings, with no saddle intonation. The treble bleed option puts 1 nF in parallel with 150 kΩ across the top half of each volume pot. Other values are common too, and you can change both. The cable is about 15 feet (450 pF) into a 1 MΩ amp input.