The Science
of Guitar Tone

Teaching weeks: 12
Signal stages: 12
Assessments: 3
Level: 2000

A vibrating string is not yet a sound, and a sound is not yet a tone. This course follows one guitar signal through every stage that stands between them — string, pickup, circuit, gain, clipping, filter, modulation, delay, amplifier, speaker — and asks the same question at each one: what physically changed, and what did that do to the waveform?

Start at week 01 The whole chain

Method

Tone words describe a listener.
This course describes the signal.

Nothing here is anti-vocabulary — “warm” and “bright” are useful shorthand, and every engineer uses them. They are just not explanations. Each week takes one of them apart and puts back what physically changed, what that did to the waveform, and why the result sounds the way it does.

warm
Upper harmonics rolled off
A filter, a pickup position or a tone control has reduced everything above roughly the fourth harmonic. The fundamental is untouched; its neighbours are not.
Weeks 3, 4, 7
bright
Fundamental weak relative to its harmonics
Sensing the string close to the bridge samples a point where the lowest mode barely moves, so the partials above it dominate the balance that leaves the guitar.
Week 3
aggressive
Partials that were not in the input
Clipping flattens the peaks of the waveform. A flattened wave is a different wave, and its Fourier series contains partials the clean signal never had.
Weeks 5, 6

The course

Twelve weeks, one signal chain

Each week is the next stage the signal passes through, and takes as its input whatever the week before it produced. Two of those stages are transductions — where the signal stops being one kind of thing and starts being another.

Listening bench

One performance.
Three signal chains.

The same dry recording of an open low E runs through all three — the course's one canonical DI take, reused by every guitar demonstration on the site. Nothing about the playing changes between them, so anything you hear change is the processing.

CH 01
Clean
1. DI
2. Neck
3. EQ 6k
4. Gain ×0.5
5. Amp
6. Flat cab
Neck position, little gain, a wide-open filter. Close to the string's own shape.
CH 02
Driven
1. DI
2. Bridge
3. EQ 3k
4. Gain ×1.6
5. Asym. clip
6. Amp
7. Dark cab
Bridge position, a darker filter, and enough gain to round the peaks asymmetrically — still tracking the pick attack.
CH 03
Full chain
1. DI
2. Bridge
3. Gain ×1.2
4. Fuzz
5. EQ 3k2
6. Mod
7. Reverb
8. Amp
9. Dark cab
Every stage engaged at once: a gentler fuzz clipping, modulation, reverb, a darker cabinet — more processed than Driven, not buried by it.

Audio never plays on its own — press play to start, press again to stop. The processing is simplified browser DSP built to make one relationship audible at a time, not an emulation of any particular amplifier or pedal. Week 5 onward takes each stage apart on its own.

Each assessment may only assume what the course has already covered by the time it is due, so the three of them track the chain rather than sampling it at random.

Assessment

Analyse, then manipulate, then design

Two nickel-covered humbucking pickups mounted on the deep red mahogany body of an electric guitar, with the strings running across their pole pieces toward the bridge. — Photo: John Tuggle CC BY 2.0

Start here

Week 01 — where a tone begins, and what is already fixed before a string is touched.

The twelve weeks run in order, and each one takes the previous week's output as its input. If you only read one to see how the course argues, read Week 03, where string motion becomes voltage.

Begin week 01 All twelve weeks

SLOP2186 · Slop University · Semester 1 2027

Tone words describe a listener.This course describes the signal.

Twelve weeks, one signal chain

One performance.Three signal chains.

Clean

Driven

Full chain

Analyse, then manipulate, then design

Where to go next

Tone words describe a listener.
This course describes the signal.

One performance.
Three signal chains.