Fake echo / delay

What it is#

Repeat each melody note after a fixed time (say 3 or 6 pattern rows) at much lower volume, and again even quieter. On a spare channel it becomes a lush echo; on the same channel, placed in the gaps of the melody, it fills space for free. Rule of thumb: first echo ≈ 40 % of the original volume, second ≈ 15 %; delay times that match the tempo (dotted 8th = 6 rows of 16ths) always groove (source: s-037-lab).

How to do it#

Any tracker#

Copy the melody column, paste it 3 or 6 rows lower into a free channel (or into the gaps of the same channel), lower its volume, and optionally use a duller instrument.

SID-Wizard#

Per-note volume is the instrument-column effect $5x (sustain level = note volume), so an echo note is the same note with a lower $5x, or a separate quieter echo instrument. $1D xx (Extra player) delays a whole track by $00–$FF frames and $1E xx delays a single note by up to tempo−3 frames — (unverified suggestion) a duplicated track with $1D gives a delay finer than one row (source of the commands: s-sid-wizard-manual).

LSDj#

Two native shortcuts: Rxy retrig with a decreasing volume digit — the manual's RF4 "retrig the sound every fourth tick, decreasing amplitude (echo effect)" — gives a same-channel echo without extra rows (retrigger); and a second pulse channel playing the same chain a few steps later with a lower E amplitude or a quieter instrument, panned to the other side with O (stereo-panning). Dxx delays a note by ticks for finer offsets than a step (source: s-lsdj-manual).

Hypnogram's groove delay: give the echoing pulse channel a groove whose first line lasts 0A ticks, so every note after it arrives 4 ticks late; the next phrase returns to groove 0 and keeps the offset; a second groove whose last line lasts 2 ticks cancels it — finetune the two pulses apart to thicken (source: s-intense-tech-07-groove-and-tick-tricks-part-2). danimal cannon's rule for a spare channel: double, echo, octave or detune what is already there, "compensate volume to taste" (source: s-chipmusic-lsdj-advanced-tricks).

A delay inside one channel (source: s-painperdu-03-isometric-sav-walkthrough): two instruments that differ only in panning — one L, one R — alternating in a single channel, playing the same phrase offset by three notes. "It's like a delay of this, offset by three, all in one channel." The alternative he names is an AUTOMATE table with L/R and an H (stereo-panning); he used two instruments because those instruments' tables were already busy with pulse-width modulation and a slight vibrato.

Typed echoes, and the two-position lag (source: s-lsdj-and-you-echo-chamber). Write the echo as notes in the gaps, played by a second instrument with the same sound at a lower volume and a shorter envelope — and pitch each echo to the note before last, not to the note it follows: in a C – B – G – E run, the echo after B is the C, the echo after G is the B. Carry the previous phrase's last note in as the first echo of the next so the loop stays continuous. From there: pan the echo instrument to one side ("panned echoes are often used in professionally produced tracks, and the trick works well in LSDJ"), or run an automated table that pans it left and right on alternate notes. Spending a second channel buys a chorus rather than an echo — copy the phrases into pulse 2, shift them one tick later, lower the volume and set PU FINE TUNE to 2, which "will create a sort of chorus effect when the notes play in unison with pulse channel one" (detune). roboctopus's habit is to leave the echoes to the end: "in the final stages of working on a track, I often look for every bit of free space in the patterns and see if I can add an echo here and there."

Sample trackers#

The "standard techno echo" of the 1990s PC scene: copy a column to another channel with an offset of 2 or 3 rows and lower its volume (GBlues, source: s-tw055-panning-debate); pan the echo to the other side of the source, or spread several echoes across the stereo field (Vivid, source: s-tw059-tracking-hints). Alternatives when channels are short: impulse-tracker's retrigger Qxy with a volume decrease, or a looped reverb tail shaped by a volume envelope so the "echo" lives inside the instrument (instrument-envelopes; source: s-tw081-it-tip-of-the-week). Necros's numbers for a lead echo (source: s-tw012-advanced-tracking-tips): copy the track, ALT-J its volume to at least a third lower — 22 from 64; "I hate leads where people copy the track, move it down, and forget to drop the volume" — and offset it two or three rows at speed 6, four or six at speed 3 so the delay sits on the beat; pan it the same distance on the other side of the lead, or hard on the lead's own side (stereo-panning, lead-articulation).

The manuals' own echo tools (sources: s-st3-manual, s-protracker-23d-help, s-ft2-manual): ST3's block mix — "set the skip level to 2 and write the melody. Then copy the melody to an adjacent channel, lower its volume with ALT-J, insert it one row, and mix it with the original melody"; Alt-I/Alt-J multiply volumes by 3/2 or 2/3 "for creating echoes". ProTracker: ED0 delays a note "a little anyway. You can play the same note on two channels, delay one, and get a nice flanging effect", the Edit Op Echo function bakes an echo into a sample ("If you want more room to echo in, just turn up the length of the sample"), and Ctrl+J join-pastes a block over existing notes. FT2's sample editor extension has an Echo command too.

Airon (1998) calls this channel echo "a primitive version" of a reverb's early reflections; the real thing has to be baked into the sample offline — see reverb-and-compression (source: s-tw118-reverb-and-compression).

Impulse Tracker#

Pulse's own hint: copy the column and set a channel volume M20 at the top of the echo channel — "you won't have to modify the echoing channel from the original", the Dxx slides stay right. StereoMan's reverb-like version: copy the sequence one or two rows later, zero its volumes (Alt-V, Alt-W) and fade every echo note in with Dx0 slides; pan the pair apart (X22/XDD or X80 + S91) for "stunning" results (sources: s-it-manual, s-it-hints).

Single-voice echo in the classic drivers#

Neil Baldwin, describing "another old C64 trick" he reused on the NES: "Instead of using two voices, one playing a melody and the second at a lower volume but slightly delayed, the single-voice method used slightly truncated note lengths and in the gaps in between notes, play the same notes shifted later in time, quickly dropping the voice volume (and then restoring it to play the next melody note)". martin-galway lists "chorusing/echoes" with fast arpeggios as the tricks that made three channels sound like more (source: s-newman-driving-the-sid-chip).

Two forum-era descriptions of the same two tricks on the SID: 4mat loops an instrument's preset "with the gate off so it fades out which gives the echo effect" — the single-voice version (source: s-chipmusic-sid-music-hints-n-tips); n00bstar: "The classic chiptune delay is a single tap delay either 3 or 4 quarter notes behind the original signal", done "by wasting another channel", which is why the delay voice is "the first to get sacrificed" when the arrangement needs the channel (source: s-chipmusic-typical-sid-sounds).

Delayed copies in 256 bytes (Tiny Sid 2, 2006)#

• Jeff's X-Large 5, as Tognon read it in a sid2mid dump before covering it: voices 2 and 3 play voice 1's line two and four notes late on triangle with sustain/release $69 and $29 against the lead's $C9 — "a sort of low echo" — and the whole tune is one pattern stream per voice with equal note lengths, which is why it fitted in 256 bytes (source: s-sidin10-tiny-sid-2-part-1).
• Eric Odland's Miniature Rhapsody copies voice 1's note into voice 2 one frame later (lda voice1Note / sta voice2Note before each update) — a one-frame chorus on the arpeggio for two instructions (source: s-sidin10-tiny-sid-2-part-1).

Tips & pitfalls#

• Same-channel echo only works where the melody has rests — write the melody with gaps first (melody-writing).
• Echo the end of phrases, not every note, when channels are tight.

Echo by shared streams (Galway, Dunn)#

In Arkanoid's tune 6, voices 2 and 3 select their own instrument and then JMP into voice 1's byte-code stream after staggered rests ($BF,$04 / $BF,$01 against voice 1's $BF,$1B) — one pattern played three times with delays, a delayed echo without copying data; tune 7 does it with explicit copies offset by $15/$0B/$01 ticks (source: s-realdmx-galway-arkanoid-player). Dunn's SUCCESS jingle plays the same phrase (FMEL1) on two voices two frames apart (REST,2 first) — a cheap chorus (source: s-realdmx-ocean-dunn-hughes-driver).

Three voices from one nibble stream (xxlarge, under 256 bytes)#

In Ninja/theDream's xxlarge (SIDin #7) the pattern data is a single stream of note nibbles for voice 1; on every advancing call the player shifts the previous voice-1 note to voice 2 and the one before that to voice 3 (mus_v1pos → v2pos, via a buffer, → v3pos), so voices 2 and 3 (triangle, their own sustain/release) trail voice 1 (pulse) by one and two steps — the shared-stream echo of Galway and Dunn reduced to three zero-page bytes (unverified reading of the listing, which the article prints but does not discuss; source: s-sidin07-xxlarge).

Related#

channel-interleaving · melody-writing · arrangement · reverb-and-compression

Sources#

s-037-lab · s-sid-wizard-manual · s-newman-driving-the-sid-chip · s-intense-tech-07-groove-and-tick-tricks-part-2 · s-chipmusic-lsdj-advanced-tricks · s-st3-manual · s-protracker-23d-help · s-ft2-manual · s-tw012-advanced-tracking-tips · s-lsdj-manual · s-tw055-panning-debate · s-tw059-tracking-hints · s-tw081-it-tip-of-the-week · s-it-manual · s-it-hints · s-tw118-reverb-and-compression · s-realdmx-galway-arkanoid-player · s-realdmx-ocean-dunn-hughes-driver · s-sidin07-xxlarge · s-sidin10-tiny-sid-2-part-1 · s-chipmusic-sid-music-hints-n-tips · s-chipmusic-typical-sid-sounds · s-lsdj-and-you-echo-chamber · s-painperdu-03-isometric-sav-walkthrough