Delay — effect atlas

10 effects · 1,103 captures. Echo effects, from simple stereo delays to cross-feedback and tempo-synced designs. The click-and-tail probe gives each echo as a signed tap, so the cards show the actual delay-line topology, the recirculation period, the loss per repeat and whether feedback inverts polarity.

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

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

knob_counts = {'Cross Delay': (9, 1), 'Ctrl Delay 1': (8, 3), 'Ctrl Delay 2': (7, 4), 'Delay L,C,R': (9, 2), 'Delay L,R': (9, 2), 'Delay L,R St': (9, 2), 'Echo': (12, 1), 'Tempo Cross Delay': (9, 1), 'Tempo Delay 1': (6, 3), 'Tempo Delay 2': (6, 3)}
show(cards.family_overview(df, 'Delay', knob_counts, curves))

Show code

iviz.family_fig(df, curves, 'Delay').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.

Identical curves (under 0.5 dB apart), so the same processing at these settings — a shared tone stage, or, for an EQ left flat, no shaping beyond the capture chain: Cross Delay = Ctrl Delay 1 = Ctrl Delay 2; Delay L,R = Delay L,R St = Echo; Tempo Delay 1 = Tempo Delay 2. Less reliable in detail (repeat captures differ by over 3 dB, usually a running LFO): Echo, Tempo Cross Delay. 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. Curves that overlap exactly mean those effects do the same thing to your tone at these settings.

In other words, the main points:

• Most shaping: Tempo Delay 1, 22 dB from peak to deepest cut.
• Same tone curve (within 0.5 dB): Cross Delay = Ctrl Delay 1 = Ctrl Delay 2; Delay L,R = Delay L,R St = Echo; Tempo Delay 1 = Tempo Delay 2.
• Least repeatable in detail (usually a running LFO): Echo, Tempo Cross Delay.

Show code

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

Echo map: where every repeat lands

Delay times and feedback describe an echo pattern in numbers; this chart shows the pattern itself, in time and across the stereo field.

Show code

import kinetics, kviz, wviz, rviz
show_parts(kviz.echo_parts(df, curves) + wviz.echo_parts(g))

What it shows. One click sent to both channels through each delay at its default settings, and every echo that comes back, drawn like notes on a stave: one line per effect.

How to read it. Time after the click runs left to right. On each effect's dotted line, a dot above the line is an echo in the left speaker (cyan), below it the right (amber), on it the centre (white); bigger dots are louder echoes. The thin line joins the echoes in order, so a zig-zag is a ping-pong delay.

What it found.

• Cross Delay bounces between left and right (5 echoes read, typically 280 ms apart).
• Ctrl Delay 1 stays in the centre (3 echoes read, typically 830 ms apart).
• Ctrl Delay 2 stays in the centre (3 echoes read, typically 615 ms apart).
• Delay L,C,R bounces between left and right (9 echoes read, typically 140 ms apart).
• Delay L,R bounces between left and right (10 echoes read, typically 140 ms apart).
• Delay L,R St bounces between left and right (6 echoes read, typically 290 ms apart).
• Echo alternates sides in pairs (10 echoes read, typically 140 ms apart).
• Only echoes within about 45 dB of the loudest are read, so long feedback tails stop early here.

What it shows. A click through each delay with the dry sound mixed in, recorded at every tested setting of one time control. Every echo that came back is a dot.

How to read it. Time after the click runs left to right; each row is one setting of the control, lowest at the bottom. Cyan dots (upper of each pair) are left-speaker echoes, amber (lower) right; bigger dots are bigger echoes. A column of dots that leans to the right is an echo this control moves; a column that stands straight is one it leaves alone. Use the slider to change effect and control.

What it found.

• The 28 echo lines that follow a fine (14-bit) time control move 0.1000 ms per step (smallest 0.1000, largest 0.1000); Yamaha documents 0.1 ms.
• Lag moves its echo 0.996 ms per step (documented as 1 ms).
• 12 controls move echoes on one side only (Delay L,C,R Delay Time L, Delay L,C,R Delay Time R, Delay L,R Delay Time L, Delay L,R Delay Time R, Delay L,R St Delay Time L, Delay L,R St Delay Time R, Delay L,R St Feedback Time L, Delay L,R St Feedback Time R, Echo Delay Time L1, Echo Delay Time L2, Echo Delay Time R1, Echo Delay Time R2); 11 move both sides together (Cross Delay Delay Time L to R, Cross Delay Delay Time R to L, Ctrl Delay 1 Delay Time, Ctrl Delay 2 Delay Time, Delay L,C,R Delay Time C, Delay L,C,R Feedback Time, Delay L,R Feedback Time 1, Delay L,R Feedback Time 2, Tempo Cross Delay Lag, Tempo Delay 1 Lag, Tempo Delay 2 Lag).

---

Cross Delay

Show code

show_card('Cross Delay')

Cross Delay: what the measurements say

Recap. A delay with 10 tested controls, 9 of which measurably change the sound. Beyond mix and level, the biggest lever is Delay Time R to L: loss per pass -33.0 → -16.3 dB. 1 does nothing with the others at default. Measured with 105 captures: 55 on the main sweep + tone probe (one control at a time), 22 on matched probes (impulseTail ×19, stereoRouting ×3), 28 two-control pairs.

Technical explanation. At default settings: output -29.9 dBFS RMS (crest 17.0 dB); stereo width 0.70, L/R correlation +0.01; spectral tilt +0.40 dB/octave; 100% of the impulse response's energy in its first 5 ms; decay T30 2.13 s, EDT 2.71 s.

Structure:

• set delay times: P1 420 ms, P2 560 ms
• no direct sound (fully wet); first arrival at 420 ms; 100% of the echo energy lands on a sum of set delays
• L: 560 ms (+0 dB) = 560, 980 ms (-16 dB) = 420 + 560, 1540 ms (-33 dB) = 420 + 560 + 560
• R: 420 ms (-0 dB) = 420, 980 ms (-17 dB) = 420 + 560, 1400 ms (-33 dB) = 420 + 420 + 560
• 20% of echo times are shared between the two channels

Two-control pairs captured: Delay Time L to R×EQ High Gain, Delay Time L to R×EQ Low Gain, Delay Time L to R×Feedback Level, Delay Time R to L×Delay Time L to R, Delay Time R to L×EQ High Gain, Delay Time R to L×EQ Low Gain, EQ High Gain×EQ Low Gain (interaction analysis in the main notebook).

Caveats:

• EQ Low Freq did nothing because the matching gain sits at 0 dB in the one-at-a-time design

Plain explanation: The control to reach for first is Delay Time R to L: loss per pass -33.0 → -16.3 dB. After that, Delay Time L to R, EQ High Gain and EQ Low Gain make the next biggest differences. DryWet sets how much of the effect you hear and how loud it is. EQ Low Freq made no measurable difference with the other controls at default. At default the tail takes about 2.1 s to die away. At default left and right are largely independent, so it sounds wide.

In other words, the main points:

• 9 of 10 tested controls measurably change the sound; 1 does nothing with the others at default.
• Biggest lever beyond mix and level: Delay Time R to L, 16.7× the smallest change that matters (loss per pass -33.0 → -16.3 dB).
• At default: stereo width 0.70, decay T30 2.13 s, output -29.9 dBFS RMS.
• Main caveat: EQ Low Freq did nothing because the matching gain sits at 0 dB in the one-at-a-time design.
• Still to measure: T1, T13, T2b, T5 (see TESTS_NEEDED.md).

Show code

show_knobs('Cross Delay')

barely changes the soundchanges it a lot■no measurable changeall to default

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.

Not shown, because these recordings show no measurable change from them: EQ Low Freq.

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

show_gapfill('Cross Delay')

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-L-to-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 1 to 1,638 at raw 16383.

Delay-Time-R-to-L · 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 1 to 1,638 at raw 16383.

Feedback-High-Damp · sweepTail. Played: a sweep followed by silence. The line is dB treble per repeat: how much treble each repeat loses compared with the one before; here it goes from 13.8 at raw 0 to 14.5 at raw 10, dipping to 13.3.

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 -0.499 at raw 1 to -0.5 at raw 127, dipping to -15.2.

Input-Select · 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 -15.4 at raw 0 to -15.3 at raw 2, dipping to -15.7.

---

Ctrl Delay 1

Show code

show_card('Ctrl Delay 1')

Ctrl Delay 1: what the measurements say

Recap. A delay with 11 tested controls, 8 of which measurably change the sound. Beyond mix and level, the biggest lever is Feedback Level: decay time 0.03 → 7.98 s. 3 do nothing with the others at default. Measured with 106 captures: 59 on the main sweep + tone probe (one control at a time), 23 on matched probes (impulseTail ×23), 24 two-control pairs.

Technical explanation. At default settings: output -27.6 dBFS RMS (crest 15.0 dB); stereo width 0.07, L/R correlation +0.99; spectral tilt +0.37 dB/octave; 100% of the impulse response's energy in its first 5 ms; decay T30 3.50 s, EDT 5.40 s.

Structure:

• set delay times: P1 420 ms
• a direct sound is present; 85% of the echo energy lands on a sum of set delays
• L: 0 ms (+0 dB) = direct, 830 ms (-16 dB) = unexplained, 1660 ms (-33 dB) = unexplained
• R: 0 ms (-0 dB) = direct, 830 ms (-17 dB) = unexplained, 1660 ms (-33 dB) = unexplained
• 100% of echo times are shared between the two channels

Two-control pairs captured: Delay Time Offset×Delay Time, Delay Time Offset×EQ High Gain, Delay Time×Feedback Level, EQ High Gain×Delay Time, Feedback Level×Delay Time Offset, Feedback Level×EQ High Gain (interaction analysis in the main notebook).

Caveats:

• EQ High Freq, EQ Low Freq did nothing because the matching gain sits at 0 dB in the one-at-a-time design

Plain explanation: The control to reach for first is Feedback Level: decay time 0.03 → 7.98 s. After that, Delay Time Offset, EQ High Gain and Delay Time make the next biggest differences. DryWet sets how much of the effect you hear and how loud it is. EQ High Freq, EQ Low Freq and Feedback High Damp made no measurable difference with the other controls at default. At default the tail takes about 3.5 s to die away. At default the output is close to mono.

In other words, the main points:

• 8 of 11 tested controls measurably change the sound; 3 do nothing with the others at default.
• Biggest lever beyond mix and level: Feedback Level, 31.4× the smallest change that matters (decay time 0.03 → 7.98 s).
• At default: stereo width 0.07, decay T30 3.50 s, output -27.6 dBFS RMS.
• Main caveat: EQ High Freq, EQ Low Freq did nothing because the matching gain sits at 0 dB in the one-at-a-time design.
• Still to measure: T1, T13, T5 (see TESTS_NEEDED.md).

Show code

show_knobs('Ctrl Delay 1')

barely changes the soundchanges it a lot■no measurable changeall to default

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.

Not shown, because these recordings show no measurable change from them: EQ High Freq, EQ Low Freq, Feedback High Damp.

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

show_gapfill('Ctrl Delay 1')

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 2.11 at raw 1 to 7.64 at raw 14860.

Delay-Time-Offset · impulseTail. Played: a single click followed by silence. The line is ms recirculation: the time between successive repeats; here it goes from 420 at raw 0 to 1,486 at raw 127.

Delay-Transition-Rate · impulseTail. Played: a single click followed by silence. The line is ms recirculation: the time between successive repeats; here it goes from 830 at raw 1 to 498 at raw 48.

Feedback-High-Damp · sweepTail. Played: a sweep followed by silence. The line is dB treble per repeat: how much treble each repeat loses compared with the one before; here it goes from 13.6 at raw 0 to 13.9 at raw 10, peaking at 14.5, dipping to 12.2.

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 -0.521 at raw 1 to -0.522 at raw 127, dipping to -15.2.

---

Ctrl Delay 2

Show code

show_card('Ctrl Delay 2')

Ctrl Delay 2: what the measurements say

Recap. A delay with 11 tested controls, 7 of which measurably change the sound. Beyond mix and level, the biggest lever is Delay Transition Rate: first right echo 615 → 2 ms. 4 do nothing with the others at default. Measured with 106 captures: 59 on the main sweep + tone probe (one control at a time), 23 on matched probes (impulseTail ×23), 24 two-control pairs.

Technical explanation. At default settings: output -27.3 dBFS RMS (crest 14.7 dB); stereo width 0.35, L/R correlation +0.76; spectral tilt +0.38 dB/octave; 100% of the impulse response's energy in its first 5 ms; decay T30 2.60 s, EDT 3.94 s.

Structure:

• set delay times: P1 420 ms
• a direct sound is present; 85% of the echo energy lands on a sum of set delays
• L: 0 ms (+0 dB) = direct, 615 ms (-16 dB) = unexplained, 1230 ms (-33 dB) = unexplained
• R: 0 ms (-0 dB) = direct, 615 ms (-17 dB) = unexplained, 1230 ms (-33 dB) = unexplained
• 100% of echo times are shared between the two channels

Two-control pairs captured: Delay Time×Delay Time Offset, Delay Time×Feedback Level, Delay Transition Rate×Delay Time, Delay Transition Rate×Delay Time Offset, Delay Transition Rate×Feedback Level, Feedback Level×Delay Time Offset (interaction analysis in the main notebook).

Caveats:

• EQ High Freq, EQ Low Freq did nothing because the matching gain sits at 0 dB in the one-at-a-time design

Plain explanation: The control to reach for first is Delay Transition Rate: first right echo 615 → 2 ms. After that, Feedback Level, Delay Time and Delay Time Offset make the next biggest differences. DryWet sets how much of the effect you hear and how loud it is. Control Type, EQ High Freq, EQ Low Freq and Feedback High Damp made no measurable difference with the other controls at default. At default the tail takes about 2.6 s to die away. At default it has a moderate stereo spread.

In other words, the main points:

• 7 of 11 tested controls measurably change the sound; 4 do nothing with the others at default.
• Biggest lever beyond mix and level: Delay Transition Rate, 62.1× the smallest change that matters (first right echo 615 → 2 ms).
• At default: stereo width 0.35, decay T30 2.60 s, output -27.3 dBFS RMS.
• Main caveat: EQ High Freq, EQ Low Freq did nothing because the matching gain sits at 0 dB in the one-at-a-time design.
• Still to measure: T1, T13, T5 (see TESTS_NEEDED.md).

Show code

show_knobs('Ctrl Delay 2')

barely changes the soundchanges it a lot■no measurable changeall to default

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.

Not shown, because these recordings show no measurable change from them: Control Type, EQ High Freq, EQ Low Freq, Feedback High Damp.

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

show_gapfill('Ctrl Delay 2')

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 1 at raw 1 to 7.64 at raw 14860.

Delay-Time-Offset · impulseTail. Played: a single click followed by silence. The line is ms recirculation: the time between successive repeats; here it goes from 420 at raw 0 to 1,160 at raw 127.

Delay-Transition-Rate · impulseTail. Played: a single click followed by silence. The line is ms recirculation: the time between successive repeats; here it goes from 615 at raw 1 to 253 at raw 48.

Feedback-High-Damp · sweepTail. Played: a sweep followed by silence. The line is dB treble per repeat: how much treble each repeat loses compared with the one before; here it goes from 13.6 at raw 0 to 14.1 at raw 10, peaking at 15.8, dipping to 13.4.

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 -0.48 at raw 1 to -0.48 at raw 127, dipping to -15.2.

---

Delay L,C,R

Show code

show_card('Delay L,C,R')

Delay L,C,R: what the measurements say

Recap. A delay with 12 tested controls, 9 of which measurably change the sound. Beyond mix and level, the biggest lever is Feedback Time: echo tail T30 0.01 → 8.60 s. 2 do nothing with the others at default. Measured with 120 captures: 67 on the main sweep + tone probe (one control at a time), 25 on matched probes (impulseTail ×25), 28 two-control pairs.

Technical explanation. At default settings: output -29.0 dBFS RMS (crest 19.1 dB); stereo width 0.64, L/R correlation +0.17; spectral tilt +0.52 dB/octave; 29% of the impulse response's energy in its first 5 ms; decay T30 2.23 s, EDT 3.40 s.

Structure:

• set delay times: P1 420 ms, P2 560 ms, P3 340 ms, P4 500 ms
• no direct sound (fully wet); first arrival at 340 ms; 100% of the echo energy lands on a sum of set delays
• L: 340 ms (-6 dB) = 340, 420 ms (+0 dB) = 420, 840 ms (-22 dB) = 340 + 500, 920 ms (-16 dB) = 420 + 500, 1340 ms (-38 dB) = 340 + 500 + 500, 1420 ms (-33 dB) = 420 + 500 + 500
• R: 340 ms (-6 dB) = 340, 560 ms (-0 dB) = 560, 840 ms (-22 dB) = 340 + 500, 1060 ms (-17 dB) = 500 + 560, 1340 ms (-39 dB) = 340 + 500 + 500, 1560 ms (-33 dB) = 500 + 500 + 560
• 33% of echo times are shared between the two channels

Two-control pairs captured: Delay Time L×Feedback Time, EQ High Gain×Delay Level C, EQ High Gain×EQ Low Gain, EQ Low Gain×Delay Level C, Feedback Time×Delay Level C, Feedback Time×EQ High Gain, Feedback Time×EQ Low Gain (interaction analysis in the main notebook).

Caveats:

• EQ High Freq, EQ Low Freq did nothing because the matching gain sits at 0 dB in the one-at-a-time design

Plain explanation: The control to reach for first is Feedback Time: echo tail T30 0.01 → 8.60 s. After that, EQ High Gain, EQ Low Gain and Delay Level C make the next biggest differences. DryWet sets how much of the effect you hear and how loud it is. EQ High Freq and EQ Low Freq made no measurable difference with the other controls at default. At default the tail takes about 2.2 s to die away. At default left and right are largely independent, so it sounds wide.

In other words, the main points:

• 9 of 12 tested controls measurably change the sound; 2 do nothing with the others at default.
• Biggest lever beyond mix and level: Feedback Time, 38.7× the smallest change that matters (echo tail T30 0.01 → 8.60 s).
• At default: stereo width 0.64, decay T30 2.23 s, output -29.0 dBFS RMS.
• Main caveat: EQ High Freq, EQ Low Freq did nothing because the matching gain sits at 0 dB in the one-at-a-time design.
• Still to measure: T1, T13, T2b, T5 (see TESTS_NEEDED.md).

Show code

show_knobs('Delay L,C,R')

barely changes the soundchanges it a lot■no measurable changeall to default

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.

Not shown, because these recordings show no measurable change from them: EQ High Freq, EQ Low Freq.

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

show_gapfill('Delay L,C,R')

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-C · 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 2.26 at raw 1 to 124 at raw 16383.

Delay-Time-L · 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 1 to 341 at raw 16383.

Delay-Time-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 1 to 341 at raw 16383.

Feedback-High-Damp · sweepTail. Played: a sweep followed by silence. The line is dB treble per repeat: how much treble each repeat loses compared with the one before; here it goes from -6.59 at raw 0 to 3.93 at raw 10.

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 -0.495 at raw 1 to -0.494 at raw 127, peaking at 5.6, dipping to -4.32.

Feedback-Time · 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 5.61 at raw 1 to 5.6 at raw 16383, dipping to -17.3.

---

Delay L,R

Show code

show_card('Delay L,R')

Delay L,R: what the measurements say

Recap. A delay with 11 tested controls, 9 of which measurably change the sound. Beyond mix and level, the biggest lever is Delay Time L: first left echo 500 → 1638 ms. 2 do nothing with the others at default. Measured with 113 captures: 62 on the main sweep + tone probe (one control at a time), 23 on matched probes (impulseTail ×23), 28 two-control pairs.

Technical explanation. At default settings: output -30.2 dBFS RMS (crest 17.2 dB); stereo width 0.69, L/R correlation +0.04; spectral tilt +0.48 dB/octave; 29% of the impulse response's energy in its first 5 ms; decay T30 2.37 s, EDT 3.17 s.

Structure:

• set delay times: P1 420 ms, P2 560 ms, P3 500 ms, P4 650 ms
• no direct sound (fully wet); first arrival at 420 ms; 100% of the echo energy lands on a sum of set delays
• L: 420 ms (+0 dB) = 420, 920 ms (-22 dB) = 420 + 500, 1070 ms (-22 dB) = 420 + 650, 1570 ms (-39 dB) = 420 + 500 + 650, 1720 ms (-45 dB) = 420 + 650 + 650
• R: 560 ms (-0 dB) = 560, 1060 ms (-23 dB) = 500 + 560, 1210 ms (-23 dB) = 560 + 650, 1710 ms (-39 dB) = 500 + 560 + 650, 1860 ms (-45 dB) = 560 + 650 + 650
• 0% of echo times are shared between the two channels

Two-control pairs captured: Delay Time L×Delay Time R, Delay Time L×EQ Low Gain, Delay Time L×Feedback Time 1, Delay Time L×Feedback Time 2, Delay Time R×EQ Low Gain, Delay Time R×Feedback Time 2, EQ Low Gain×Feedback Time 2 (interaction analysis in the main notebook).

Caveats:

• EQ Low Freq did nothing because the matching gain sits at 0 dB in the one-at-a-time design

Plain explanation: The control to reach for first is Delay Time L: first left echo 500 → 1638 ms. After that, Delay Time R, EQ Low Gain and Feedback Time 2 make the next biggest differences. DryWet sets how much of the effect you hear and how loud it is. EQ Low Freq and Feedback High Damp made no measurable difference with the other controls at default. At default the tail takes about 2.4 s to die away. At default left and right are largely independent, so it sounds wide.

In other words, the main points:

• 9 of 11 tested controls measurably change the sound; 2 do nothing with the others at default.
• Biggest lever beyond mix and level: Delay Time L, 12.5× the smallest change that matters (first left echo 500 → 1638 ms).
• At default: stereo width 0.69, decay T30 2.37 s, output -30.2 dBFS RMS.
• Main caveat: EQ Low Freq did nothing because the matching gain sits at 0 dB in the one-at-a-time design.
• Still to measure: T1, T13, T2b, T5 (see TESTS_NEEDED.md).

Show code

show_knobs('Delay L,R')

barely changes the soundchanges it a lot■no measurable changeall to default

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.

Not shown, because these recordings show no measurable change from them: EQ Low Freq, Feedback High Damp.

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

show_gapfill('Delay L,R')

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-L · 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 1 to 1,638 at raw 16383.

Delay-Time-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 1 to 1,638 at raw 16383.

Feedback-High-Damp · sweepTail. Played: a sweep followed by silence. The line is dB treble per repeat: how much treble each repeat loses compared with the one before; here it goes from 10.7 at raw 0 to 10.5 at raw 10, dipping to 10.2.

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 -0.362 at raw 1 to -0.362 at raw 127, dipping to -10.6.

Feedback-Time-1 · 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 -22.9 at raw 1 to -11.6 at raw 16383.

Feedback-Time-2 · 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 -22.9 at raw 1 to -11.6 at raw 16383.

---

Delay L,R St

Show code

show_card('Delay L,R St')

Delay L,R St: what the measurements say

Recap. A delay with 11 tested controls, 9 of which measurably change the sound. Beyond mix and level, the biggest lever is Delay Time L: first left echo 500 → 1638 ms. 2 do nothing with the others at default. Measured with 109 captures: 62 on the main sweep + tone probe (one control at a time), 23 on matched probes (impulseTail ×23), 24 two-control pairs.

Technical explanation. At default settings: output -29.7 dBFS RMS (crest 16.6 dB); stereo width 0.71, L/R correlation +0.00; spectral tilt +0.48 dB/octave; 29% of the impulse response's energy in its first 5 ms; decay T30 2.78 s, EDT 2.14 s.

Structure:

• set delay times: P1 420 ms, P2 560 ms, P3 500 ms, P4 650 ms
• no direct sound (fully wet); first arrival at 420 ms; 100% of the echo energy lands on a sum of set delays
• L: 420 ms (+0 dB) = 420, 920 ms (-16 dB) = 420 + 500, 1420 ms (-33 dB) = 420 + 500 + 500
• R: 560 ms (-0 dB) = 560, 1210 ms (-17 dB) = 560 + 650, 1860 ms (-33 dB) = 560 + 650 + 650
• 0% of echo times are shared between the two channels

Two-control pairs captured: Delay Time L×Delay Time R, Delay Time L×EQ Low Gain, Delay Time L×Feedback Time L, Delay Time R×EQ Low Gain, Delay Time R×Feedback Time L, Feedback Time L×EQ Low Gain (interaction analysis in the main notebook).

Caveats:

• EQ High Freq, EQ Low Freq did nothing because the matching gain sits at 0 dB in the one-at-a-time design

Plain explanation: The control to reach for first is Delay Time L: first left echo 500 → 1638 ms. After that, Delay Time R, Feedback Time L and EQ Low Gain make the next biggest differences. DryWet sets how much of the effect you hear and how loud it is. EQ High Freq and EQ Low Freq made no measurable difference with the other controls at default. At default the tail takes about 2.8 s to die away. At default left and right are largely independent, so it sounds wide.

In other words, the main points:

• 9 of 11 tested controls measurably change the sound; 2 do nothing with the others at default.
• Biggest lever beyond mix and level: Delay Time L, 12.5× the smallest change that matters (first left echo 500 → 1638 ms).
• At default: stereo width 0.71, decay T30 2.78 s, output -29.7 dBFS RMS.
• Main caveat: EQ High Freq, EQ Low Freq did nothing because the matching gain sits at 0 dB in the one-at-a-time design.
• Still to measure: T1, T13, T2b, T5 (see TESTS_NEEDED.md).

Show code

show_knobs('Delay L,R St')

barely changes the soundchanges it a lot■no measurable changeall to default

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.

Not shown, because these recordings show no measurable change from them: EQ High Freq, EQ Low Freq.

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

show_gapfill('Delay L,R St')

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-L · 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 1 to 1,638 at raw 16383.

Delay-Time-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 1 to 1,638 at raw 16383.

Feedback-High-Damp · sweepTail. Played: a sweep followed by silence. The line is dB treble per repeat: how much treble each repeat loses compared with the one before; here it goes from 14.8 at raw 0 to 14.1 at raw 10, peaking at 14.9, dipping to 13.6.

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 -0.49 at raw 1 to -0.49 at raw 127, dipping to -15.3.

Feedback-Time-L · 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 1 to 0.0454 at raw 16383.

Feedback-Time-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 1 to 0.0454 at raw 16383.

---

Echo

Show code

show_card('Echo')

Echo: what the measurements say

Recap. A delay with 13 tested controls, 12 of which measurably change the sound. Beyond mix and level, the biggest lever is Delay Time L1: recirculating line 520 → 1638 ms. 1 does nothing with the others at default. Measured with 128 captures: 72 on the main sweep + tone probe (one control at a time), 28 on matched probes (impulseTail ×17, spectralSweep ×11), 28 two-control pairs.

Technical explanation. At default settings: output -29.7 dBFS RMS (crest 19.1 dB); stereo width 0.71, L/R correlation +0.01; spectral tilt +0.47 dB/octave; 29% of the impulse response's energy in its first 5 ms; decay T30 2.17 s, EDT 2.84 s.

Structure:

• set delay times: P1 380 ms, P3 520 ms, P6 760 ms, P7 900 ms
• no direct sound (fully wet); first arrival at 380 ms; 100% of the echo energy lands on a sum of set delays
• L: 380 ms (+0 dB) = 380, 760 ms (-6 dB) = 760, 1140 ms (-22 dB) = 380 + 760, 1520 ms (-38 dB) = 760 + 760
• R: 520 ms (-0 dB) = 520, 900 ms (-7 dB) = 900, 1040 ms (-17 dB) = 520 + 520, 1420 ms (-24 dB) = 520 + 900, 1560 ms (-33 dB) = 520 + 520 + 520, 1940 ms (-40 dB) = 520 + 520 + 900
• 0% of echo times are shared between the two channels

Two-control pairs captured: Delay Time L1×Delay Time R1, Delay Time L1×Delay Time R2, Delay Time L1×EQ High Gain, Delay Time L1×Feedback Level L, Delay Time R1×Delay Time R2, Delay Time R1×EQ High Gain, Delay Time R2×EQ High Gain (interaction analysis in the main notebook).

Caveats:

• EQ Low Freq did nothing because the matching gain sits at 0 dB in the one-at-a-time design

Plain explanation: The control to reach for first is Delay Time L1: recirculating line 520 → 1638 ms. After that, Delay Time R1, Delay Time R2 and EQ High Gain make the next biggest differences. DryWet sets how much of the effect you hear and how loud it is. EQ Low Freq made no measurable difference with the other controls at default. At default the tail takes about 2.2 s to die away. At default left and right are largely independent, so it sounds wide.

In other words, the main points:

• 12 of 13 tested controls measurably change the sound; 1 does nothing with the others at default.
• Biggest lever beyond mix and level: Delay Time L1, 12.0× the smallest change that matters (recirculating line 520 → 1638 ms).
• At default: stereo width 0.71, decay T30 2.17 s, output -29.7 dBFS RMS.
• Main caveat: EQ Low Freq did nothing because the matching gain sits at 0 dB in the one-at-a-time design.
• Still to measure: T1, T13, T2b, T5 (see TESTS_NEEDED.md).

Show code

show_knobs('Echo')

barely changes the soundchanges it a lot■no measurable changeall to default

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.

Not shown, because these recordings show no measurable change from them: EQ Low Freq.

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

show_gapfill('Echo')

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-L1 · 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 1 to 761 at raw 16383.

Delay-Time-L2 · 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 1 to 379 at raw 16383.

Delay-Time-R1 · 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 1 to 901 at raw 16383.

Delay-Time-R2 · 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 1 to 519 at raw 16383.

Feedback-High-Damp · sweepTail. Played: a sweep followed by silence. The line is dB treble per repeat: how much treble each repeat loses compared with the one before; here it goes from 8.43 at raw 0 to 7.96 at raw 10, dipping to 7.7.

Feedback-Level-L · 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 -4.18 at raw 1 to -3.84 at raw 127, dipping to -8.93.

Feedback-Level-R · 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 -6.17 at raw 1 to -6.17 at raw 127, dipping to -9.53.

---

Tempo Cross Delay

Show code

show_card('Tempo Cross Delay')

Tempo Cross Delay: what the measurements say

Recap. A delay with 11 tested controls, 9 of which measurably change the sound. Beyond mix and level, the biggest lever is Feedback Level: changes output level by +13.9 dB. 1 does nothing with the others at default. Measured with 112 captures: 60 on the main sweep + tone probe (one control at a time), 24 on matched probes (rhythmicGrid ×21, stereoRouting ×3), 28 two-control pairs.

Technical explanation. At default settings: output -20.3 dBFS RMS (crest 16.6 dB); stereo width 0.24, L/R correlation +0.89; spectral tilt +1.36 dB/octave; 93% of the impulse response's energy in its first 5 ms; decay T30 0.64 s, EDT 1.04 s.

Two-control pairs captured: Delay Time L to R×Feedback Level, Delay Time R to L×EQ High Gain, Delay Time R to L×EQ Low Gain, EQ High Gain×EQ Low Gain, Feedback Level×Delay Time R to L, Feedback Level×EQ High Gain, Feedback Level×EQ Low Gain (interaction analysis in the main notebook).

Caveats:

• EQ Low Freq did nothing because the matching gain sits at 0 dB in the one-at-a-time design

Plain explanation: The control to reach for first is Feedback Level: changes output level by +13.9 dB. After that, Delay Time R to L, EQ High Gain and EQ Low Gain make the next biggest differences. DryWet sets how much of the effect you hear and how loud it is. EQ Low Freq made no measurable difference with the other controls at default. At default the tail takes about 0.6 s to die away. At default it has a moderate stereo spread.

In other words, the main points:

• 9 of 11 tested controls measurably change the sound; 1 does nothing with the others at default.
• Biggest lever beyond mix and level: Feedback Level, 14.0× the smallest change that matters (changes output level by +13.9 dB).
• At default: stereo width 0.24, decay T30 0.64 s, output -20.3 dBFS RMS.
• Main caveat: EQ Low Freq did nothing because the matching gain sits at 0 dB in the one-at-a-time design.
• Still to measure: T1, T13, T5 (see TESTS_NEEDED.md).

Show code

show_knobs('Tempo Cross Delay')

barely changes the soundchanges it a lot■no measurable changeall to default

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.

Not shown, because these recordings show no measurable change from them: EQ Low Freq.

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

show_gapfill('Tempo Cross Delay')

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-L-to-R · 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 17.3 at raw 0 to 10.8 at raw 19, dipping to 2.02.

Delay-Time-R-to-L · 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 5.19 at raw 0 to 15.4 at raw 19, dipping to 1.07.

Feedback-High-Damp · sweepTail. Played: a sweep followed by silence. The line is dB treble per repeat: how much treble each repeat loses compared with the one before; here it goes from 14.4 at raw 0 to 12.7 at raw 10, peaking at 14.8.

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 -0.475 at raw 1 to -0.475 at raw 127, dipping to -15.3.

Input-Select · 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 -15.5 at raw 0 to -14.9 at raw 2.

Lag · 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 1.94 at raw 0 to 2.43 at raw 127.

---

Tempo Delay 1

Show code

show_card('Tempo Delay 1')

Tempo Delay 1: what the measurements say

Recap. A delay with 10 tested controls, 6 of which measurably change the sound. Beyond mix and level, the biggest lever is Delay Time: decay time 0.03 → 6.16 s. 3 do nothing with the others at default. Measured with 102 captures: 57 on the main sweep + tone probe (one control at a time), 21 on matched probes (rhythmicGrid ×21), 24 two-control pairs.

Technical explanation. At default settings: output -27.4 dBFS RMS (crest 15.2 dB); stereo width 0.06, L/R correlation +0.99; spectral tilt +0.55 dB/octave; 94% of the impulse response's energy in its first 5 ms; decay T30 0.66 s, EDT 0.92 s.

Two-control pairs captured: Delay Time×EQ Low Gain, Delay Time×Feedback Level, Delay Time×Lag, Feedback Level×EQ Low Gain, Feedback Level×Lag, Lag×EQ Low Gain (interaction analysis in the main notebook).

Caveats:

• EQ High Freq, EQ Low Freq did nothing because the matching gain sits at 0 dB in the one-at-a-time design

Plain explanation: The control to reach for first is Delay Time: decay time 0.03 → 6.16 s. After that, Feedback Level, Lag and EQ Low Gain make the next biggest differences. DryWet sets how much of the effect you hear and how loud it is. EQ High Freq, EQ Low Freq and Feedback High Damp made no measurable difference with the other controls at default. At default the tail takes about 0.7 s to die away. At default the output is close to mono.

In other words, the main points:

• 6 of 10 tested controls measurably change the sound; 3 do nothing with the others at default.
• Biggest lever beyond mix and level: Delay Time, 30.0× the smallest change that matters (decay time 0.03 → 6.16 s).
• At default: stereo width 0.06, decay T30 0.66 s, output -27.4 dBFS RMS.
• Main caveat: EQ High Freq, EQ Low Freq did nothing because the matching gain sits at 0 dB in the one-at-a-time design.
• Still to measure: T1, T13, T5 (see TESTS_NEEDED.md).

Show code

show_knobs('Tempo Delay 1')

barely changes the soundchanges it a lot■no measurable changeall to default

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.

Not shown, because these recordings show no measurable change from them: EQ High Freq, EQ Low Freq, Feedback High Damp.

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

show_gapfill('Tempo Delay 1')

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 0.0476 at raw 0 to 15.2 at raw 19.

Feedback-High-Damp · sweepTail. Played: a sweep followed by silence. The line is dB treble per repeat: how much treble each repeat loses compared with the one before; here it goes from 14.8 at raw 0 to 14.5 at raw 10, peaking at 15.8, dipping to 13.3.

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 -0.439 at raw 1 to -0.44 at raw 127, dipping to -15.3.

LR-Diffusion · 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 1.61 at raw 0 to 1.63 at raw 127, peaking at 1.76.

Lag · 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 1.6 at raw 0 to 2.25 at raw 127.

---

Tempo Delay 2

Show code

show_card('Tempo Delay 2')

Tempo Delay 2: what the measurements say

Recap. A delay with 10 tested controls, 6 of which measurably change the sound. Beyond mix and level, the biggest lever is Feedback Level: decay time 6.16 → 1.52 s. 3 do nothing with the others at default. Measured with 102 captures: 57 on the main sweep + tone probe (one control at a time), 21 on matched probes (rhythmicGrid ×21), 24 two-control pairs.

Technical explanation. At default settings: output -27.5 dBFS RMS (crest 15.3 dB); stereo width 0.33, L/R correlation +0.78; spectral tilt +0.55 dB/octave; 94% of the impulse response's energy in its first 5 ms; decay T30 0.66 s, EDT 0.92 s.

Two-control pairs captured: Delay Time×EQ High Gain, Delay Time×Feedback Level, Delay Time×Lag, EQ High Gain×Lag, Feedback Level×EQ High Gain, Feedback Level×Lag (interaction analysis in the main notebook).

Caveats:

• EQ High Freq, EQ Low Freq did nothing because the matching gain sits at 0 dB in the one-at-a-time design

Plain explanation: The control to reach for first is Feedback Level: decay time 6.16 → 1.52 s. After that, Delay Time, EQ High Gain and Lag make the next biggest differences. DryWet sets how much of the effect you hear and how loud it is. EQ High Freq, EQ Low Freq and Feedback High Damp made no measurable difference with the other controls at default. At default the tail takes about 0.7 s to die away. At default it has a moderate stereo spread.

In other words, the main points:

• 6 of 10 tested controls measurably change the sound; 3 do nothing with the others at default.
• Biggest lever beyond mix and level: Feedback Level, 30.0× the smallest change that matters (decay time 6.16 → 1.52 s).
• At default: stereo width 0.33, decay T30 0.66 s, output -27.5 dBFS RMS.
• Main caveat: EQ High Freq, EQ Low Freq did nothing because the matching gain sits at 0 dB in the one-at-a-time design.
• Still to measure: T1, T13, T5 (see TESTS_NEEDED.md).

Show code

show_knobs('Tempo Delay 2')

barely changes the soundchanges it a lot■no measurable changeall to default

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.

Not shown, because these recordings show no measurable change from them: EQ High Freq, EQ Low Freq, Feedback High Damp.

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

show_gapfill('Tempo Delay 2')

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 0.0476 at raw 0 to 15.2 at raw 19.

Feedback-High-Damp · sweepTail. Played: a sweep followed by silence. The line is dB treble per repeat: how much treble each repeat loses compared with the one before; here it goes from 14.6 at raw 0 to 14.1 at raw 10, peaking at 15.4.

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 -0.441 at raw 1 to -0.442 at raw 127, dipping to -15.3.

LR-Diffusion · 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 1.61 at raw 0 to 1.63 at raw 127, peaking at 1.76.

Lag · 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 1.6 at raw 0 to 2.25 at raw 127.

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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.