LOOPSOUNDloops a tape you play from the keyslight / dark

LOOP

LOOP is a loop of tape you record onto and play from the keys. It uses the tape echo's own tape, so the echo is off while LOOP is the SOUND in front. Leaving LOOP gives the tape back to the echo, which clears it: what you recorded is gone when you come back, and the screen says LOOP: TAPE CLEARED as you leave. There is no room for a second tape, and no undo.

loops a tape you play from the keys

Half

SOUND

Reach it

a custom build, FELUCCA_LOOP=1 (else on PHYS)

ALGORITHM

SPEED

Engine

LOOP

Factory sounds

5

Playing it

LOOP records what the other parts send to the delay: a pair running behind (RUDIMENT, ALIVE), the patterns of the other parts, or MIDI coming in. Turn a part's DLY send up on its FX page, switch REC on, and the tape fills; switch REC off and the loop holds as it is. FDBK decides how much of the old loop survives each pass while REC is on, so a low FDBK replaces the loop and a high one layers on top of it. Turn LOOP's own DLY send down, or the keys record themselves back onto the tape.

The tape plays all the time, through the delay's MIX. The keys play it as well, through heads of their own: C4 plays it as recorded, and every other key plays it higher or lower, faster or slower. On the KEYS page, MODE TAPE runs the loop at the key's speed and GRAIN scatters short grains from it at the key's pitch, without changing its time.

SPEED is the whole tape's speed in semitones, so everything on it changes pitch and time together. MOTOR STOP winds the tape down to silence and REV runs it backwards; INERT sets how long either takes, as the weight of the reels would. QUAL trades the tape's length for its fidelity, and a change of QUAL wipes the tape. SPLCE cuts the loop shorter; a new length takes effect when the loop next comes round, so it never clicks. WOW adds the tape's wobble.

The screen shows the tape as a reel: the loop is the coloured arc, the heads are the dot moving round it, and the number is the loop's length in seconds.

MAIN

Pages

TAPE

Knob	Label	Range	Starts at
1	SPEED	-24st .. +24st	0st
2	REC	OFF ON	OFF
3	FDBK	0% .. 100%	79%
4	MOTOR	PLAY STOP REV	PLAY

DECK

QUAL HI records at the full rate in 16 bits, MID at half the rate, LO in 8 bits at half the rate and CASS in 8 bits at a quarter: each step down doubles the tape's length. MID and LO are filtered to about 8 kHz, CASS to about 4 kHz.

Knob	Label	Range	Starts at
1	QUAL	HI MID LO CASS	HI
2	INERT	0% .. 100%	31%
3	SPLCE	1% .. 100%	100%
4	WOW	0% .. 100%	8%

KEYS

POS is where on the loop a key starts. GRAIN is a grain's length and SPRAY how far the grains' starts scatter.

Knob	Label	Range	Starts at
1	MODE	TAPE GRAIN	TAPE
2	POS	0% .. 100%	0%
3	GRAIN	0% .. 100%	31%
4	SPRAY	0% .. 100%	0%

KEYS 2

SCAN moves GRAIN's starts through the loop: at 64 they move with the tape; at 0 they hold at POS.

LOOP is on the sidelines: SQRL-1's build leaves it out. A custom build with FELUCCA_LOOP=1 brings it back, picked on the PAIR page (hold HOME, tap GLO, KNOB 1). Without it, a LOOP sound in a project or a saved sound plays on PHYS.

Knob	Label	Range	Starts at
1	SCAN	0 .. 127	64

Where it comes from

LOOP follows the tape loops of the 1960s and Expert Sleepers' Augustus Loop; the code is databurn's own. The tape is firmware/src/tapeloop.c, from databurn (MIT), and the engine firmware/src/eng_loop.c.