vimsynth/modules/catch

modules/sources/CATCH

CATCH

The rack's SHORT-TERM MEMORY: a micro-looper with no start command. It is always listening — recording into a ring nobody named — and the catch gate does not start it, it says KEEP WHAT JUST HAPPENED. Play something, decide afterwards that you wanted it, and it is already there. Length is in BEATS off clk (down to a sixteenth, which at any usual tempo is a grain rather than a phrase). Three ways to play the loop back: tape (a speed, forwards or backwards), stretch (grains creeping through it, so it plays at pitch while moving slower than it was recorded) and env (your PLAYING interrupts it — loud stops the playhead dead, quiet lets it crawl, which is time-stretching by touch). Dropping catch erases and re-records in place. dub overdubs, and fade below 1 makes the loop a delay you play into. keep promotes the caught loop into a bank slot, where GRAIN, SLICE and SMPL can get at it. Reach for it for glitch, stutter, texture from live playing, or anything described as caught, fleeting, half-remembered.

The CATCH card as vimsynth draws it: its title bar, 10 knobs, 8 inputs down the left edge and 3 outputs down the right
CATCH on an empty rack — 32×30 cells, knobs at their defaults. Press a in the app and pick CATCH to get this card.

inputs

Down the left edge of the card, top to bottom.

laudio
What it listens to, left. It is recording this whenever catch is low — always, without being asked.
raudio
The right side. Normals from l, so one cable in is a mono looper.
clktrigger
The beat the loop's length is measured in. Patch the same CLOCK the rest of the patch runs on and the loops line up with it. With nothing here a beat is assumed to be half a second (120 BPM) until two edges have been seen.
catchgate
KEEP WHAT JUST HAPPENED. The rising edge stops the recording and takes the len beats that already went by; while it stays high the loop plays. Dropping it does not pause — it goes back to listening, which means recording over the loop.
dubgate
Overdub: play the loop AND write on top of it. fade decides how much of the previous pass survives each time round.
keeptrigger
Writes the caught loop into bank slot slot, where GRAIN, SLICE and SMPL can reach it — short-term memory promoted to long-term. It goes in mono, as everything the bank holds does.
speed cvcv
Moves playback speed, summed with the knob. Through zero and negative, so a slow LFO here rocks the loop backwards and forwards.
clock cvcv
Moves the whole thing's rate in octaves, summed with the knob — 1.0 is an octave up and twice the speed.

outputs

Down the right edge, in the same order.

laudio
The loop, left. Silent while it is listening — it has nothing to say until you catch something.
raudio
The right side. With spread up in tape mode this plays the loop FORWARDS while the left plays it backwards, which turns one caught chord into a room.
thruaudio
The input, untouched, so this drops into the middle of a chain without a MIXER to split the signal.

knobs

Left to right across the face — the dials in the picture.

modetape · stretch · env= tape
How the loop plays back. tape runs a playhead at speed, forwards or backwards — the one that keeps the audio recognisable. stretch reads it with overlapping grains that creep through the loop slower than it was recorded, so it holds its pitch while slowing down. env hands the playhead to your PLAYING: see sense.
len1/16 · 1/8 · 1/4 · 1/2 · 1 · 2 · 4 · 8= 1
How long a loop is, in BEATS of whatever is patched into clk. 1/16 and 1/8 are grains and stutters; 1 and 2 are phrases. Changing it does not disturb a loop already caught — it decides what the NEXT catch takes.
speed-4 … 4 x= 1 x
Playback speed in tape mode, ±4×. Negative is backwards, and reverse is not a special case anywhere — it is a negative rate, so it can be swept through zero.
stretch-1 … 1= 0
How far stretch pulls the reading rate away from the playing rate. 0 plays the loop as recorded; up slows the walk through it without changing pitch; negative walks BACKWARDS through the loop while every grain still plays forwards, which is the sound of a tape being rewound while it plays.
sense0 … 1= 0.5
How loud the input has to be to interrupt env playback. Low is touchy — the smallest sound stops the loop dead. High and only a hard hit does it. The trick the mode exists for: crank it, then tap the strings gently, and the loop slows to a crawl instead of stopping.
clock-3 … 1 oct= 0 oct
The rate the whole thing runs at, in OCTAVES — the pedal's CLOCK knob, which is a sample rate. Down one is half speed and an octave lower, and the loop takes twice as long to get round. For the grit that a real falling sample rate brings with it, patch a CRUSH: this is the speed, not the quality.
fade0 … 1= 1
How much of the previous pass survives an overdub. 1.0 is a loop that never decays. Below it the loop is a DELAY you play into — every pass a little quieter — and around 0.5 a phrase is gone in a few bars.
spread0 … 1= 0
How far the two sides diverge. In tape the right side plays forwards while the left plays the same loop BACKWARDS, so one caught chord becomes a room.
mix0 … 1= 1
Dry/wet. At 1.0 you hear only the loop, which is usually right — the input is already on thru.
slot0 … 63= 0
Which bank slot keep writes to.

more

The full reference — every parameter curve, the patching notes and the worked examples — lives in the manual: docs.vimsynth.com/modules/catch. In the app itself, :help CATCH opens the same page without leaving the rack.