Tech — effect atlas¶

6 effects · 697 captures. Special effects — scratch, ring modulation, auto-synth and similar. Few of the standard features apply cleanly; the cards lean on the measured response and stereo behaviour.

Part of the Motif ES effects teardown; the method and the cross-effect findings are in the main analysis (notebook).

How to read a card¶

Each effect gets one card, then a written breakdown.

Header band. The effect's name, category, how many recordings exist, and a one-sentence summary written from the measurements.
Tiles. The handful of numbers that matter most for this type of effect, at default settings. A dash means the value could not be measured, and the small caption says why.
The knob console. One knob per control. Click a knob to select it and move the slider under the knobs to turn it. A knob's ring is its own travel, coloured stretch by stretch: green where turning it barely changes the sound, red where a small turn changes it a lot, grey where nothing measurable happens. A knob outlined in cyan was also recorded together with the selected one, and its ring changes as the slider moves; every other ring shows that knob with the rest at their defaults. Controls that showed no measurable change at all are listed under the console, not drawn.
What each knob does. One bar per control, longest first. Bar length is the size of the change the knob makes, in multiples of the smallest change that matters in practice (1 dB of level, 20% of decay time, 10% of LFO rate…), on a log scale. Colour says what kind of change. ◆ marks readings taken with a test sound designed for that knob. Grey dots are knobs that did nothing with the other controls at default.
Signature panel. The view that best explains this kind of effect: decay curves for a reverb, echo taps for a delay, the input/output curve for a compressor, harmonics against input level for a distortion, the LFO for a modulation effect.
Knob × frequency. Each row is one knob at one tested setting; red means louder than default at that frequency, blue quieter. Modulation effects get a what the knobs touch matrix instead, because a running LFO has no single frequency response.
Stereo. How the left and right inputs reach the outputs.

The breakdown under each card notes the structure the measurements reveal, flags caveats, and names the tests in TESTS_NEEDED.md that would complete the picture. Below it, every knob is charted with the range tested and what it does; hover a bar for the detail.

Show code

In [1]:

import warnings; warnings.filterwarnings("ignore")
import sys; sys.path.insert(0, "..")
import os; os.chdir("..")                   # the cache lives in the project root
import matplotlib.pyplot as plt
from IPython.display import HTML, Markdown, display
import load, knobs, cards, plots, iviz, gapfill, knobviz, vizstyle as V
V.setup()
from matplotlib_inline.backend_inline import set_matplotlib_formats
set_matplotlib_formats("svg")           # figures embed as vector, not PNG
display(iviz.page_css())
df, curves = load.load()
noise = knobs.noise_table(df, curves)
g = gapfill.load()

def show(fig):
    display(fig)
    plt.close(fig)

def show_card(effect):
    show(cards.effect_card(df, curves, effect, noise)[0])

def show_knobs(effect):
    board = knobviz.console(df, curves, effect, noise)
    if board is not None:
        display(board)
    _, main, rh = cards.merged_knobs(df, curves, effect, noise)
    for h in iviz.knob_plots(effect, main, rh):
        display(h)

def show_parts(parts):
    for f, note in parts:           # each chart, then its own explanation directly under it
        f.show()
        display(Markdown(note))

def show_gapfill(effect, stimuli=None, drives_only=False):
    parts = iviz.gf_effect_parts(g, effect, stimuli, drives_only)
    if parts:
        display(Markdown(iviz.GF_INTRO))
    show_parts(parts)

The family at a glance¶

Every effect in the category on the same few numbers, then all of them on one chart — drag the slider to bring one forward, hover for exact values.

Show code

In [2]:

knob_counts = {'Auto Synth': (15, 0), 'Digital Scratch': (11, 0), 'Isolator': (7, 0), 'Jump': (9, 0), 'Slice': (14, 0), 'Tech Mod': (14, 0)}
show(cards.family_overview(df, 'Tech', knob_counts, curves))

No description has been provided for this image

Show code

In [3]:

iviz.family_fig(df, curves, 'Tech').show()

Recap. Why: to compare the tone of every effect in the family on one chart. How to read it: each line is one effect's frequency response, centred on its own median; drag the slider to bring one forward, hover for exact values.

Technical explanation. Each effect's frequency response at the capture baseline — how much each frequency is boosted or cut on its way through — measured by log-sweep deconvolution, smoothed to 1/6 octave, averaged over repeat captures, and shifted to its own median so the chart compares tone shape, not loudness. Drag the slider to bring one effect forward. The chart below this text reads each curve off as three numbers: its peak, the range within 6 dB of the peak, and the span from peak to deepest cut.

Less reliable in detail (repeat captures differ by over 3 dB, usually a running LFO): Auto Synth, Digital Scratch, Jump, Slice, Tech Mod. These effects move while they are measured, so each curve is one snapshot of a response that sweeps back and forth; read the overall tilt, not individual notches. The LFO maps in the cards and in §14 of the main analysis show the movement itself. Not shown: level (each curve is centred on its own median), anything that changes over time.

Plain explanation: this is the effect's tone — which parts of the sound it makes louder or quieter. Because these effects sweep constantly, think of each line as a single frame of a moving picture.

In other words, the main points:

Most shaping: Jump, 34 dB from peak to deepest cut.
Least repeatable in detail (usually a running LFO): Auto Synth, Digital Scratch, Jump, Slice, Tech Mod.

Show code

In [4]:

iviz.tone_bands(df, curves, 'Tech')

Out[4]:

Chopping and movement, from moment to moment¶

Several of these effects work by switching the sound on and off or moving it; this chart follows each side's size through time.

Show code

In [5]:

import kinetics, kviz, wviz, rviz
show_parts(wviz.motion_parts(g, 'Tech'))

What it shows. Steady noise, the same in both speakers, through each effect at its default settings. Every 10 ms the size of what comes out of each side is compared with the same moment of the noise recorded with no effect.

How to read it. Time runs left to right. A line at 100 is that side at its average size; above is louder, below quieter. Cyan is the left side, amber the right. Lines that rise and fall together are a tremolo; lines that take turns are a pan; the shape of the wave (smooth, pointed, lopsided) is the shape of the effect's modulator. Use the slider to change effect.

What it found.

Digital Scratch: 1.78 times a second, the left side swinging between 64% and 140% of its average; the two sides move partly out of step.
Slice: 8.00 times a second, the left side swinging between 32% and 192% of its average; the two sides rise and fall together.
Holding steady (less than a 10% swing on steady noise): Isolator.
Not drawn: Auto Synth, Jump, Tech Mod.
They move, but no regular rise and fall could be read; a moving delay (as in a rotary speaker) changes the noise in ways this comparison cannot separate from loudness.

Auto Synth¶

Show code

In [6]:

show_card('Auto Synth')

Auto Synth: what the measurements say¶

Recap. An effect with 16 tested controls, 15 of which measurably change the sound. Beyond mix and level, the biggest lever is AM Depth: amplitude modulation depth 0.21 → 1.77. Measured with 139 captures: 76 on the main sweep + tone probe (one control at a time), 35 on matched probes (sustainedStereo ×13, spectralSweep ×13, impulseTail ×9), 28 two-control pairs.

Technical explanation. At default settings: output -27.5 dBFS RMS (crest 15.8 dB); stereo width 0.43, L/R correlation +0.63; spectral tilt +1.22 dB/octave; 46% of the impulse response's energy in its first 5 ms; decay T30 0.45 s, EDT 0.86 s.

Two-control pairs captured: AM Depth×Delay Time, AM Depth×Feedback Level, AM Depth×Mod Depth, Delay Time×Feedback Level, Delay Time×Mod Depth, Feedback Level×Mod Depth, Mod Speed×Mod Depth (interaction analysis in the main notebook).

Caveats:

some long settings decay more slowly than the recording allows; their T30 is a lower bound

Plain explanation: The control to reach for first is AM Depth: amplitude modulation depth 0.21 → 1.77. After that, Feedback Level, Delay Time and Mod Depth make the next biggest differences. Dry Mix Level sets how much of the effect you hear and how loud it is. At default the tail takes about 0.5 s to die away. At default it has a moderate stereo spread.

In other words, the main points:

15 of 16 tested controls measurably change the sound.
Biggest lever beyond mix and level: AM Depth, 31.1× the smallest change that matters (amplitude modulation depth 0.21 → 1.77).
At default: stereo width 0.43, decay T30 0.45 s, output -27.5 dBFS RMS.
Main caveat: some long settings decay more slowly than the recording allows; their T30 is a lower bound.
Still to measure: T1, T4 (see TESTS_NEEDED.md).

Show code

In [7]:

show_knobs('Auto Synth')

barely changes the soundchanges it a lot■no measurable change

Click a knob to select it, then move the slider to turn it. A ring is that knob's own travel: green stretches barely change the sound, red stretches change it a lot. Rings show each knob with the others at their defaults; a knob outlined in cyan was also recorded together with the selected one, and its ring follows the slider.

Gap Fill: each control in physical units¶

Every control stepped on a probe matched to what it does (17 steps for time and rate controls, 9 for the rest), read as the physical quantity it sets: how far a delay tap moves, level or treble lost per repeat, LFO rate and pitch swing, gate length, THD, intermodulation, compressor ratio, knee, attack and release, and where a gate opens and closes. Times are read inside one capture (channel against channel) because Gap Fill runs fully wet and file starts wander by about ±50 ms.

Show code

In [8]:

show_gapfill('Auto Synth')

How to read these charts. Each chart is one control. Left to right is the control's raw value as sent to the Motif (low to high setting); the height of the line is the physical quantity that control sets, measured from the recording. The title names the control, then the test signal used.

AM-Depth · sustainedStereo. Played: a held chord, one note per channel. The line is cents pitch swing: how far the pitch bends, peak to peak (100 cents = one semitone); here it barely moves (about 1.38 throughout).

AM-Speed · longSine. Played: a steady 440 Hz sine. The line is Hz LFO rate: how many times a second the modulation cycles; here it barely moves (about 21.4 throughout).

AM-Wave · longSine. Played: a steady 440 Hz sine. The line is Hz LFO rate: how many times a second the modulation cycles; here it barely moves (about 21.4 throughout).

Delay-Time · sweepTail. Played: a sweep followed by silence. The line is s T30: the reverb decay time (extrapolated to 60 dB of decay); here it goes from 3.3 at raw 0 to 2.9 at raw 3700, peaking at 3.44.

Delay-Time-Offset-R · sweepTail. Played: a sweep followed by silence. The line is ms the tap moves: how far the echo moves in time against the other channel; here it goes from 0 at raw 0 to 0 at raw 884, peaking at 453, dipping to -460.

Feedback-Level · sweepTail. Played: a sweep followed by silence. The line is dB per repeat: how much quieter each repeat is than the one before; closer to 0 means more repeats; here it goes from -0.0784 at raw 1 to -0.0603 at raw 127, peaking at 0.121, dipping to -2.12.

Mod-Depth · sustainedStereo. Played: a held chord, one note per channel. The line is cents pitch swing: how far the pitch bends, peak to peak (100 cents = one semitone); here it goes from 0.166 at raw 0 to 0.624 at raw 127, peaking at 25.3.

Mod-Depth-Offset-R · sustainedStereo. Played: a held chord, one note per channel. The line is cents pitch swing: how far the pitch bends, peak to peak (100 cents = one semitone); here it goes from 10.5 at raw 0 to 0.865 at raw 127.

Mod-Speed · longSine. Played: a steady 440 Hz sine. The line is Hz LFO rate: how many times a second the modulation cycles; here it goes from 4.71 at raw 7 to 17 at raw 31, dipping to 3.2.

Mod-Speed · sustainedStereo. Played: a held chord, one note per channel. The line is Hz LFO rate: how many times a second the modulation cycles; here it barely moves (about 5.04 throughout).

Mod-Wave-Type · longSine. Played: a steady 440 Hz sine. The line is Hz LFO rate: how many times a second the modulation cycles; here it goes from 21.4 at raw 0 to 14.8 at raw 3, peaking at 23.

Digital Scratch¶

Show code

In [9]:

show_card('Digital Scratch')

Digital Scratch: what the measurements say¶

Recap. An effect with 11 tested controls, 11 of which measurably change the sound. Beyond mix and level, the biggest lever is Scratch Speed: pitch wobble 220 → 35 cents. Measured with 110 captures: 56 on the main sweep + tone probe (one control at a time), 26 on matched probes (spectralSweep ×13, stereoRouting ×5, sustainedStereo ×5, impulseTail ×3), 28 two-control pairs.

Technical explanation. At default settings: output -18.3 dBFS RMS (crest 13.9 dB); stereo width 0.35, L/R correlation +0.75; spectral tilt +3.92 dB/octave; 5% of the impulse response's energy in its first 5 ms; decay T30 3.21 s, EDT 1.10 s.

Two-control pairs captured: EQ Width×Scratch Depth, Initial Delay×HPF Freq, Initial Delay×Scratch Depth, Scratch Depth×HPF Freq, Scratch Speed×HPF Freq, Scratch Speed×Initial Delay, Scratch Speed×Scratch Depth (interaction analysis in the main notebook).

Caveats:

some long settings decay more slowly than the recording allows; their T30 is a lower bound

Plain explanation: The control to reach for first is Scratch Speed: pitch wobble 220 → 35 cents. After that, Initial Delay, Scratch Depth and HPF Freq make the next biggest differences. DryWet and Input Level set how much of the effect you hear and how loud it is. At default the tail takes about 3.2 s to die away. At default it has a moderate stereo spread.

In other words, the main points:

11 of 11 tested controls measurably change the sound.
Biggest lever beyond mix and level: Scratch Speed, 37.1× the smallest change that matters (pitch wobble 220 → 35 cents).
At default: stereo width 0.35, decay T30 3.21 s, output -18.3 dBFS RMS.
Main caveat: some long settings decay more slowly than the recording allows; their T30 is a lower bound.
Still to measure: T1, T4 (see TESTS_NEEDED.md).

Show code

In [10]:

show_knobs('Digital Scratch')

barely changes the soundchanges it a lot■no measurable change

Click a knob to select it, then move the slider to turn it. A ring is that knob's own travel: green stretches barely change the sound, red stretches change it a lot. Rings show each knob with the others at their defaults; a knob outlined in cyan was also recorded together with the selected one, and its ring follows the slider.

Gap Fill: each control in physical units¶

Every control stepped on a probe matched to what it does (17 steps for time and rate controls, 9 for the rest), read as the physical quantity it sets: how far a delay tap moves, level or treble lost per repeat, LFO rate and pitch swing, gate length, THD, intermodulation, compressor ratio, knee, attack and release, and where a gate opens and closes. Times are read inside one capture (channel against channel) because Gap Fill runs fully wet and file starts wander by about ±50 ms.

Show code

In [11]:

show_gapfill('Digital Scratch')

How to read these charts. Each chart is one control. Left to right is the control's raw value as sent to the Motif (low to high setting); the height of the line is the physical quantity that control sets, measured from the recording. The title names the control, then the test signal used.

Auto-Pan-Depth · stereoRouting. Played: bursts sent left only, right only, both in phase and both out of phase. The line is dB L/R isolation: how well left and right are kept apart; higher means less bleed; here it goes from -61.8 at raw 0 to -68.5 at raw 127, peaking at -61.

Auto-Pan-Speed · stereoRouting. Played: bursts sent left only, right only, both in phase and both out of phase. The line is dB L/R isolation: how well left and right are kept apart; higher means less bleed; here it goes from -63 at raw 0 to -62.4 at raw 127, peaking at -61.2, dipping to -65.

Initial-Delay · sweepTail. Played: a sweep followed by silence. The line is s T30: the reverb decay time (extrapolated to 60 dB of decay); here it goes from 2.84 at raw 0 to 3.11 at raw 4600, dipping to 2.67.

Scratch-Depth · sustainedStereo. Played: a held chord, one note per channel. The line is cents pitch swing: how far the pitch bends, peak to peak (100 cents = one semitone); here it goes from 0.0212 at raw 0 to 65.5 at raw 127, peaking at 86.4.

Scratch-Speed · longSine. Played: a steady 440 Hz sine. The line is Hz LFO rate: how many times a second the modulation cycles; here it goes from 0.336 at raw 0 to 10.4 at raw 31.

Scratch-Speed · sustainedStereo. Played: a held chord, one note per channel. The line is Hz LFO rate: how many times a second the modulation cycles; here it goes from 0.326 at raw 0 to 1.81 at raw 127, peaking at 8.04.

Isolator¶

Show code

In [12]:

show_card('Isolator')

Isolator: what the measurements say¶

Recap. An effect with 7 tested controls, 7 of which measurably change the sound. Beyond mix and level, the biggest lever is Mid Level: changes output level by +5.2 dB. Measured with 67 captures: 24 on the main sweep + tone probe (one control at a time), 15 on matched probes (spectralSweep ×15), 28 two-control pairs.

Technical explanation. At default settings: output -20.2 dBFS RMS (crest 13.0 dB); stereo width 0.33, L/R correlation +0.78; spectral tilt -0.63 dB/octave; 100% of the impulse response's energy in its first 5 ms; harmonics H2 -73 dB, H3 -43 dB re the linear response.

Two-control pairs captured: High Level×High Mute, High Level×Low Level, High Mute×Low Level, Mid Level×High Level, Mid Level×High Mute, Mid Level×Low Level, On Off×Low Level (interaction analysis in the main notebook).

Plain explanation: The control to reach for first is Mid Level: changes output level by +5.2 dB. After that, High Level, High Mute and Low Level make the next biggest differences. At default it has a moderate stereo spread.

In other words, the main points:

7 of 7 tested controls measurably change the sound.
Biggest lever beyond mix and level: Mid Level, 5.2× the smallest change that matters (changes output level by +5.2 dB).
At default: stereo width 0.33, output -20.2 dBFS RMS.
Still to measure: T1 (see TESTS_NEEDED.md).

Show code

In [13]:

show_knobs('Isolator')

barely changes the soundchanges it a lot■no measurable change

Click a knob to select it, then move the slider to turn it. A ring is that knob's own travel: green stretches barely change the sound, red stretches change it a lot. Rings show each knob with the others at their defaults; a knob outlined in cyan was also recorded together with the selected one, and its ring follows the slider.

Jump¶

Show code

In [14]:

show_card('Jump')

Jump: what the measurements say¶

Recap. An effect with 9 tested controls, 9 of which measurably change the sound. Beyond mix and level, the biggest lever is Depth: modulation depth 0.01 → 1.03 by raw 63, then modulation depth 1.03 → 0.18 by raw 127. Measured with 87 captures: 44 on the main sweep + tone probe (one control at a time), 19 on matched probes (rhythmicGrid ×19), 24 two-control pairs.

Technical explanation. At default settings: output -28.5 dBFS RMS (crest 13.7 dB); stereo width 0.35, L/R correlation +0.76; spectral tilt +1.22 dB/octave; 4% of the impulse response's energy in its first 5 ms.

Two-control pairs captured: Depth×HPF Freq, Depth×Resolution, HPF Freq×Resolution, HPF Freq×Speed, Speed×Depth, Speed×Resolution (interaction analysis in the main notebook).

Caveats:

some long settings decay more slowly than the recording allows; their T30 is a lower bound

Plain explanation: The control to reach for first is Depth: modulation depth 0.01 → 1.03 by raw 63, then modulation depth 1.03 → 0.18 by raw 127. After that, HPF Freq, Speed and Resolution make the next biggest differences. DryWet sets how much of the effect you hear and how loud it is. At default it has a moderate stereo spread.

In other words, the main points:

9 of 9 tested controls measurably change the sound.
Biggest lever beyond mix and level: Depth, 20.4× the smallest change that matters (modulation depth 0.01 → 1.03 by raw 63, then modulation depth 1.03 → 0.18 by raw 127).
At default: stereo width 0.35, output -28.5 dBFS RMS.
Main caveat: some long settings decay more slowly than the recording allows; their T30 is a lower bound.
Still to measure: T1, T4 (see TESTS_NEEDED.md).

Show code

In [15]:

show_knobs('Jump')

barely changes the soundchanges it a lot■no measurable change

Click a knob to select it, then move the slider to turn it. A ring is that knob's own travel: green stretches barely change the sound, red stretches change it a lot. Rings show each knob with the others at their defaults; a knob outlined in cyan was also recorded together with the selected one, and its ring follows the slider.

Gap Fill: each control in physical units¶

Every control stepped on a probe matched to what it does (17 steps for time and rate controls, 9 for the rest), read as the physical quantity it sets: how far a delay tap moves, level or treble lost per repeat, LFO rate and pitch swing, gate length, THD, intermodulation, compressor ratio, knee, attack and release, and where a gate opens and closes. Times are read inside one capture (channel against channel) because Gap Fill runs fully wet and file starts wander by about ±50 ms.

Show code

In [16]:

show_gapfill('Jump')

Slice¶

Show code

In [17]:

show_card('Slice')

Slice: what the measurements say¶

Recap. An effect with 14 tested controls, 14 of which measurably change the sound. Beyond mix and level, the biggest lever is Pan Depth: modulation depth 1.87 → 0.44 by raw 63, then modulation depth 0.44 → 1.88 by raw 127. Measured with 152 captures: 94 on the main sweep + tone probe (one control at a time), 30 on matched probes (rhythmicGrid ×21, stereoRouting ×9), 28 two-control pairs.

Technical explanation. At default settings: output -29.7 dBFS RMS (crest 13.9 dB); stereo width 0.33, L/R correlation +0.78; spectral tilt +0.25 dB/octave; 99% of the impulse response's energy in its first 5 ms; decay T30 7.08 s, EDT 0.02 s; harmonics H2 -67 dB, H3 -53 dB re the linear response.

Two-control pairs captured: Drive×Divide Type, EQ High Gain×Drive, EQ High Gain×Pan AEG Type, Pan AEG Type×Drive, Pan Depth×Drive, Pan Depth×EQ High Gain, Pan Depth×Pan AEG Type (interaction analysis in the main notebook).

Plain explanation: The control to reach for first is Pan Depth: modulation depth 1.87 → 0.44 by raw 63, then modulation depth 0.44 → 1.88 by raw 127. After that, EQ High Gain, Pan AEG Type and Drive make the next biggest differences. DryWet sets how much of the effect you hear and how loud it is. At default the tail takes about 7.1 s to die away. At default it has a moderate stereo spread.

In other words, the main points:

14 of 14 tested controls measurably change the sound.
Biggest lever beyond mix and level: Pan Depth, 28.7× the smallest change that matters (modulation depth 1.87 → 0.44 by raw 63, then modulation depth 0.44 → 1.88 by raw 127).
At default: stereo width 0.33, decay T30 7.08 s, output -29.7 dBFS RMS.
Still to measure: T1, T3 (see TESTS_NEEDED.md).

Show code

In [18]:

show_knobs('Slice')

barely changes the soundchanges it a lot■no measurable change

Click a knob to select it, then move the slider to turn it. A ring is that knob's own travel: green stretches barely change the sound, red stretches change it a lot. Rings show each knob with the others at their defaults; a knob outlined in cyan was also recorded together with the selected one, and its ring follows the slider.

Gap Fill: each control in physical units¶

Every control stepped on a probe matched to what it does (17 steps for time and rate controls, 9 for the rest), read as the physical quantity it sets: how far a delay tap moves, level or treble lost per repeat, LFO rate and pitch swing, gate length, THD, intermodulation, compressor ratio, knee, attack and release, and where a gate opens and closes. Times are read inside one capture (channel against channel) because Gap Fill runs fully wet and file starts wander by about ±50 ms.

Show code

In [19]:

show_gapfill('Slice')

How to read these charts. Each chart is one control. Left to right is the control's raw value as sent to the Motif (low to high setting); the height of the line is the physical quantity that control sets, measured from the recording. The title names the control, then the test signal used.

Drive · transferSine. Played: a 100 Hz sine at −6 dBFS. The line is dB THD: total harmonic distortion: how loud the added overtones are against the note itself. −40 dB is clean, 0 dB would be overtones as loud as the note; higher on the chart means more distortion; here it goes from -52.1 at raw 0 to -8.31 at raw 127.

Drive · twoToneLadder. Played: two notes together (220 and 697 Hz), stepped from very quiet to loud. The line is dB intermodulation: how loud the extra tones created between two notes are against the notes themselves, which is what makes chords sound harsh; higher means harsher; here it goes from -32.9 at raw 0 to -22.9 at raw 127, dipping to -34.2.

Pan-Depth · stereoRouting. Played: bursts sent left only, right only, both in phase and both out of phase. The line is dB L/R isolation: how well left and right are kept apart; higher means less bleed; here it barely moves (about -57.2 throughout).

Tech Mod¶

Show code

In [20]:

show_card('Tech Mod')

Tech Mod: what the measurements say¶

Recap. An effect with 14 tested controls, 14 of which measurably change the sound. Beyond mix and level, the biggest lever is FB Hi Damp Offset R: echo tail T30 0.03 → 0.84 s. Measured with 142 captures: 76 on the main sweep + tone probe (one control at a time), 30 on matched probes (sustainedStereo ×19, impulseTail ×11), 36 two-control pairs.

Technical explanation. At default settings: output -30.5 dBFS RMS (crest 16.8 dB); stereo width 0.57, L/R correlation +0.34; spectral tilt +0.94 dB/octave; 41% of the impulse response's energy in its first 5 ms.

Two-control pairs captured: Delay Time×FB Level Offset R, Delay Time×Feedback Level, FB Hi Damp Offset R×Delay Time, FB Hi Damp Offset R×FB Level Offset R, FB Hi Damp Offset R×Feedback Hi Damp, Feedback Hi Damp×Delay Time, Feedback Hi Damp×FB Level Offset R, Mod Speed×Mod Depth, Pre Mod HPF Freq×Mod LPF Resonance (interaction analysis in the main notebook).

Plain explanation: The control to reach for first is FB Hi Damp Offset R: echo tail T30 0.03 → 0.84 s. After that, Feedback Hi Damp, Delay Time and Mod LPF Freq make the next biggest differences. DryWet sets how much of the effect you hear and how loud it is. At default left and right are largely independent, so it sounds wide.

In other words, the main points:

14 of 14 tested controls measurably change the sound.
Biggest lever beyond mix and level: FB Hi Damp Offset R, 19.3× the smallest change that matters (echo tail T30 0.03 → 0.84 s).
At default: stereo width 0.57, output -30.5 dBFS RMS.
Still to measure: T1 (see TESTS_NEEDED.md).

Show code

In [21]:

show_knobs('Tech Mod')

barely changes the soundchanges it a lot■no measurable change

Click a knob to select it, then move the slider to turn it. A ring is that knob's own travel: green stretches barely change the sound, red stretches change it a lot. Rings show each knob with the others at their defaults; a knob outlined in cyan was also recorded together with the selected one, and its ring follows the slider.

Gap Fill: each control in physical units¶

Every control stepped on a probe matched to what it does (17 steps for time and rate controls, 9 for the rest), read as the physical quantity it sets: how far a delay tap moves, level or treble lost per repeat, LFO rate and pitch swing, gate length, THD, intermodulation, compressor ratio, knee, attack and release, and where a gate opens and closes. Times are read inside one capture (channel against channel) because Gap Fill runs fully wet and file starts wander by about ±50 ms.

Show code

In [22]:

show_gapfill('Tech Mod')

How to read these charts. Each chart is one control. Left to right is the control's raw value as sent to the Motif (low to high setting); the height of the line is the physical quantity that control sets, measured from the recording. The title names the control, then the test signal used.

Delay-Time · sweepTail. Played: a sweep followed by silence. The line is s T30: the reverb decay time (extrapolated to 60 dB of decay); here it goes from 8.35 at raw 0 to 6.18 at raw 7400, dipping to 6.02.

Delay-Time-Offset-R · sweepTail. Played: a sweep followed by silence. The line is ms the tap moves: how far the echo moves in time against the other channel; here it goes from 0 at raw 0 to -20 at raw 884.

Feedback-Level · sweepTail. Played: a sweep followed by silence. The line is dB per repeat: how much quieter each repeat is than the one before; closer to 0 means more repeats; here it goes from -0.432 at raw 1 to -0.526 at raw 127, peaking at 0.727, dipping to -3.02.

Mod-Depth · sustainedStereo. Played: a held chord, one note per channel. The line is cents pitch swing: how far the pitch bends, peak to peak (100 cents = one semitone); here it goes from 0.00553 at raw 0 to 12.2 at raw 127.

Mod-Speed · longSine. Played: a steady 440 Hz sine. The line is Hz LFO rate: how many times a second the modulation cycles; here it goes from 9.42 at raw 7 to 18.9 at raw 31, peaking at 31.

Mod-Speed · sustainedStereo. Played: a held chord, one note per channel. The line is Hz LFO rate: how many times a second the modulation cycles; here it goes from 5.03 at raw 39 to 5.19 at raw 95, peaking at 9.15.

Revision 36 · 2026-10-15

Revision history

Rev 36 · 2026-10-15: The Distortion drive ladders are re-recorded in the current setup (80 takes) and replace those of 2026-09-28, whose flat-topped waves came from the levels of the setup at the time, not from the effects: with the drive up, each distortion gives a square wave whose tops sag, and its Output Level only scales it.
Rev 35 · 2026-10-12: The main page folds by topic and each family's detail page folds by effect: every section is closed until opened, with one control to open or close them all.
Rev 34 · 2026-10-12: Every sheet: a play button steps through each control's settings; every recorded pair of controls drawn, with whether they simply add or one changes the other; EQ frequency and width controls drawn with their band at full boost. New detailed charts on every board: which controls depend on each other; the EQ bands moving; the ring modulator's pitch against its controls.
Rev 33 · 2026-10-12: Every control on every effect's sheet: all its tested settings overlaid in one cell, and its measured law in physical units where a probe reads one. Misc board: the equalisers' bands at full cut and boost.
Rev 32 · 2026-10-12: Headline findings set apart with larger titles; a note under the three whose graphic shows less than the headline says (Lo-Fi rate, delay feedback, repeats).
Rev 31 · 2026-10-12: Main page: a graphic under each of the eight headline findings (the delay feedback one animated), each with a plain-terms line.
Rev 30 · 2026-10-12: Main page opens with a chart of where every capture went and the central technique in pictures: the sweep, and the spikes the matched filter turns a recording of it into.
Rev 29 · 2026-10-12: Misc board: the ring modulator's carrier pitch against OSC Freq Coarse and Fine, read from the sine takes.
Rev 28 · 2026-10-11: Fifth capture batch in: the Reverb board gains the gap before the reverb starts against Initial Delay, the Chorus and Flanger boards gain the delay length against the delay knob.
Rev 27 · 2026-10-11: Waves: a third page, what the instrument and effect waves measure: the note each one plays, where it starts repeating and how long the loop is, how long it rings, and the harmonics of each pitched wave.
Rev 26 · 2026-10-11: Waves: the instrument and effect tiles now show the opening of the note (its first 8 cycles) instead of the whole take, so the individual waves can be seen.
Rev 25 · 2026-10-11: Waves: a second page for the 955 instrument and effect waves, each drawn as the whole take of one note with one cycle of the sound under it where the wave holds a steady pitch.
Rev 24 · 2026-10-08: Reverb knob pairs recorded (288 takes over the 12 distinct reverbs), so the reverb consoles' rings follow each other too; 799 knob pairs measured in all.
Rev 23 · 2026-10-08: Every family page now opens with a comparison board (one row per effect, shared scales down each column) and control sheets with all tested settings side by side; each family's detailed charts are folded in beneath and the earlier pages are kept as detail pages.
Rev 22 · 2026-10-08: Knob consoles: 2,120 new recordings of knob pairs, so within each effect's four strongest controls every knob's ring now follows every other (679 pairs measured, up from 155). A Waves page shows the 904 drum and percussion waves.
Rev 21 · 2026-10-07: Delay page rebuilt the same way: every delay's echoes side by side, and each control's tested settings next to each other as echo patterns.
Rev 20 · 2026-10-07: Reverb page rebuilt for comparison: one board with every distinct reverb as a row and every measure as a column on a shared scale, then each reverb's controls with all tested settings side by side. The detailed charts are folded in beneath; the earlier page is kept as the detail page. Knob consoles now use a slider for the selected knob, and controls with nothing measurable are listed, not drawn.
Rev 19 · 2026-10-07: A knob console on every effect: each ring shows where along the knob's travel the sound changes, and turning a knob shows how the knobs captured together with it respond.
Rev 18 · 2026-10-07: Reverb taken apart in time: how fast separate reflections merge into a wash; the tail's colour through time; how alike left and right are at each pitch and through the decay; how smooth each tail is against noise of the same tone; the Reverb Time control against Yamaha's table; and the twenty reverb names compared pair by pair.
Rev 17 · 2026-10-07: Charts that only compared output level or gain are removed from every page except the compressors and gates, where level is what the effect does.
Rev 16 · 2026-10-07: Capture set finished and audited (14,635 takes; the takes recorded through a reverb are all replaced). Corrections: Celeste 1's control shown as Delay is its Feedback Level, and Symphonic's shown as Feedback is its Delay Offset; two Symphonic controls that do not exist on the effect are removed. New charts in time and wave shape rather than level: Delay, where every echo lands as each time control is turned; Distortion, the wave that comes out as the drive rises; Lo-Fi, the output wave sample by sample at each Sampling Freq setting; Chorus and Flanger, the delay line followed as it sweeps; Phaser and Wah, where each notch or peak sits in Hz from moment to moment; Reverb, the separate early reflections in the first quarter second after one click; Modulation and Tech, each side turned up and down from moment to moment.
Rev 15 · 2026-10-06: Pitch Change: a click train in, and when each click comes out.
Rev 14 · 2026-10-06: Distortion: output and distortion against input level on a smooth ramp, harmonics against the pitch of the note, high-note harmonics folding back off 44.1 kHz (no oversampling), a bass note modulating a treble note, input-against-output loops, and the amp and cabinet filters' level and phase.
Rev 13 · 2026-10-06: Lo-Fi on a smoothly rising tone: Word Length sets a clipping ceiling and adds no quantisation noise; the five Lo-Fi effects compared on the same ramp.
Rev 12 · 2026-10-06: Lo-Fi: a rising note against everything that comes out with it, at each sampling-rate setting. Pitch Change: the cluster of lines a shifted note returns as, and the splice window read from it (about 35 ms and 28 ms).
Rev 11 · 2026-10-06: The same routing fault is confirmed for the 1,835 re-takes of 2026-09-30/10-01 (the dry-plus-wet timing takes and the full-rate Lo-Fi takes). No published chart used them; they are withdrawn from the counts and are being re-recorded.
Rev 10 · 2026-10-06: Correction: the all-effects comparison (section 17 of the main report), added earlier today, is withdrawn. Its 625 recordings were made with the Motif's System Reverb left in the signal path and are being re-recorded. New: compressor timing inside the distortion chains, wah filter sweeps, reverb decay per octave band.
Rev 9 · 2026-10-06: Follow-up captures analysed: compressor attack and release against step size, MultiBand Comp 2 band by band, Noise Gate opening, hold and closing times, and distortion on level steps (no sag: the clippers act instant by instant). Release times now require the level to stay recovered for 50 ms, which fixes readings fooled by ringing or by a delay's echo. Capture counts include the overnight batches.
Rev 8 · 2026-10-05: Beyond level curves: gain-reduction speed, release shape, phase-space orbits, harmonic matrices, intermodulation maps, parallel coordinates, a behaviour map and loudness in phon and sone on the Dynamic atlas; harmonic-against-drive matrices (Distortion), stereo LFO orbits (Chorus, Flanger, Phaser, Modulation), an echo map (Delay) and a decay-rate matrix (Reverb).
Rev 7 · 2026-10-04: All figures vector and stacked one per row; control tables replaced by interactive charts; every section in four parts (recap, professional, plain, main points); capture counts include Gap Fill; six more Gap Fill probes analysed (dynamics timing, band staircase, gate ramp, two-tone ladder, tone triplet, pink pluck).
Rev 6 · 2026-10-04: Complete 13-category analysis with detail ladders; all notebooks rebuilt with executed cells and interactive charts.
Rev 5 · 2026-10-01: T28/T29 re-take analysis (dry/wet time references, Lo-Fi full-rate captures); Reverb detail ladders.
Rev 4 · 2026-09-30: Reverb analysis from full 9,876 Gap Fill run; two-voice explanations added to main page sections 1–15.
Rev 3 · 2026-09-29: Gap Fill captures: delay and feedback time laws, LFO maps, drive transfer curves, Lo-Fi rate, early reflections; Gate/Reverse Gate relabelled; interactive charts, atlas links, dark theme.
Rev 2 · 2026-09-28: Gate Reverb time origin fixed; Auto Pan phase and Distortion harmonics computed from data.
Rev 1 · 2026-09-27: First complete report: main analysis and 13 atlas notebooks.