Manufacturer: Request For Music

Contact Request For Music

$15.00 $18.00

F_STRETCH — Time Stretch & Granular Processor

Overview

F_STRETCH is a dual-mode time processing module that combines classic granular pitch-lock stretching with varispeed tape-style playback. It allows you to slow down or speed up incoming audio while maintaining pitch or, alternatively, to emulate analog tape speed changes. With controls for grain size, overlap, jitter, stereo width and freeze, F_STRETCH covers a wide range of creative transformations: from subtle texture enhancement to extreme spectral clouds.

Signal Flow (simplified)

Input L/R → Ring Buffer → [Granular Engine] or [Varispeed Engine] → Mix → Output L/R
                                   │
                                   └── Freeze & CV Modulation

Panel I/O

  • IN L / IN R — Stereo audio inputs (R defaults to L if unconnected).
  • OUT L / OUT R — Processed stereo audio outputs.
  • MOD 1–4 — CV inputs, freely assignable to any parameter.

Controls

  • Stretch — Time factor (0.25×–4×). In Pitch-Lock mode, stretches/compresses time while keeping pitch. In Varispeed mode, directly changes playback speed and pitch.
  • Grain — Grain length in milliseconds. Longer grains are smoother but blur transients; shorter grains keep more attack detail.
  • Overlap — Number of simultaneous grains. Higher values = smoother sound but more CPU load.
  • Jitter — Random offset of grain start times (ms). Adds texture, shimmer or noisy edges.
  • Width — Stereo width of the wet signal (0–100%). Uses mid/side expansion.
  • Mix — Blend between dry input and processed output (0–100%).
  • In Gain — Input gain, ±12 dB.
  • Out Gain — Output gain, ±12 dB.
  • Mode — Switch between Pitch-Lock (granular OLA) and Varispeed (tape).
  • Freeze — When enabled, the buffer stops advancing. The captured sound becomes a static, frozen cloud.

Modulation Section

Four CV inputs are freely assignable. Each MOD jack is paired with a small assign button. Click the button to open a dropdown menu and select which parameter the CV controls (e.g. Stretch, Grain, Width, Mix, Freeze, etc.). CV inputs accept –5 V to +5 V nominal range, scaled per target:

  • ±5 V → ±1.0× stretch
  • ±5 V → ±40 ms grain
  • ±5 V → ±2 overlaps
  • ±5 V → ±10 ms jitter
  • ±5 V → ±100% width
  • ±5 V → ±40% mix
  • ±5 V → ±6 dB gain
  • ±5 V → Freeze toggle (above +1 V = ON, below –1 V = OFF)

Suggested Settings

1. Drone Texture

  • Mode: Pitch-Lock
  • Stretch: 2.0×
  • Grain: 80–120 ms
  • Overlap: 6–8
  • Jitter: 3–5 ms
  • Width: 80–100%
  • Mix: 100% Wet

Result: Smooth evolving pad, stereo “cloud” effect.

2. Percussive Loop Tight

  • Mode: Pitch-Lock
  • Stretch: 1.0×
  • Grain: 20–30 ms
  • Overlap: 2–3
  • Jitter: 0 ms
  • Width: 20–40%
  • Mix: 50% Wet

Result: Keeps transients snappy while adding granular body.

3. Frozen Granular Cloud

  • Mode: Pitch-Lock
  • Freeze: ON
  • Stretch: 1.5×
  • Grain: 60–80 ms
  • Overlap: 6+
  • Jitter: 10–20 ms
  • Width: 100%
  • Mix: 100% Wet

Result: Infinite time-stretched drone, very wide.

4. Tape Slowdown

  • Mode: Varispeed
  • Stretch: 4.0×
  • Width: 0–50%
  • Mix: 100% Wet

Result: Dramatic slowing-down “tape stop” effect.

5. Pitch-Lock Vocal Stretch

  • Mode: Pitch-Lock
  • Stretch: 3.0×
  • Grain: 40–60 ms
  • Overlap: 4–6
  • Jitter: 2–4 ms
  • Width: 50–70%
  • Mix: 80% Wet

Result: Vocals drawn out smoothly without losing pitch.

Rhythmic / Percussive

Tight Chop

  • Mode: Pitch-Lock
  • Stretch: 1.0×
  • Grain: 15 ms
  • Overlap: 1
  • Jitter: 0 ms
  • Width: 0%
  • Mix: to taste

Result: Staccato, “sliced” percussion with crisp transients.

Beat Stretcher

  • Mode: Pitch-Lock
  • Stretch: 2.0×
  • Grain: 80 ms
  • Overlap: 4
  • Jitter: 2 ms
  • Width: 30%
  • Mix: 50–100% Wet

Result: Slowed drums that remain tight, with soft smearing.

Ambient / Pads

Frozen Cloud (Alt)

  • Mode: Pitch-Lock
  • Stretch: 3.0×
  • Grain: 200 ms
  • Overlap: 8
  • Jitter: 12 ms
  • Width: 100%
  • Freeze: ON
  • Mix: 100% Wet

Result: Huge shimmering drone from any input.

Shimmer Pad

  • Mode: Pitch-Lock
  • Stretch: 1.5×
  • Grain: 120 ms
  • Overlap: 6
  • Jitter: 15 ms
  • Width: 80%
  • Mix: 70–100% Wet

Result: Lush stereo wash; great into a reverb.

Tape / Varispeed FX

Tape Stop

  • Mode: Varispeed
  • Stretch: sweep 1.0× → 4.0×
  • Width: 0%
  • Mix: 100% Wet

Result: Classic slow-down with pitch dive.

Fast Forward

  • Mode: Varispeed
  • Stretch: 0.5×
  • Width: 0%
  • Mix: 100% Wet

Result: Tape speed-up / chipmunk effect.

Special FX

Glitcher

  • Mode: Pitch-Lock
  • Stretch: 1.0×
  • Grain: 30 ms
  • Overlap: 2
  • Jitter: 20 ms
  • Width: 60%
  • Mix: 50–100% Wet

Result: Stuttering bursts with animated stereo movement.

Stereo Swarm

  • Mode: Pitch-Lock
  • Stretch: 1.0×
  • Grain: 100 ms
  • Overlap: 12
  • Jitter: 8 ms
  • Width: 100%
  • Mix: 100% Wet

Result: Wide, buzzing granular “cloud,” almost reverb-like.

Tips

  • Short grains with low overlap preserve transients but sound choppy.
  • Long grains and high overlap create smoother pads and drones.
  • Use Freeze to capture tiny textures and transform them into endless layers.
  • Modulate Stretch or Width with slow LFOs for evolving stereo ambiences.