tiptop-audio-fold

Tiptop Audio FOLD

Analog wavefolder with four sub-octave divisions

12 HP Eurorack module

The Fold Processor is a 100% analog wavefolder and subdivider module inspired by the Serge wave multiplier. It takes an input signal and folds it using a diode circuit, then feeds that folded signal into a square-and-divide circuit that produces sub-octave divisions spaced one octave apart. The result ranges from subtle harmonic enrichment to wild, pulse-width-modulated octave chaos depending on input type and knob positions.

Features

  • 100% analog diode wavefolder circuit inspired by the Serge wave multiplier middle section
  • FOLD knob with 0 to x6 gain range for progressive wavefold intensity
  • INJECT knob for DC offset into the folding circuit, adding asymmetric harmonic variation
  • CV input for FOLD with bipolar attenuator knob
  • CV input for INJECT with bipolar attenuator knob
  • Square and divide circuit converts folded output to four sub-octave signals
  • Four subdivision gain knobs: divide by 1, 2, 4, and 8 (one octave apart each)
  • Subdivisions mixed to SUBDIV OUT jack
  • Folded signal also available separately at OUT jack
  • Two audio inputs: IN 1 and IN 2
  • Works with pure waveforms from VCO or self-oscillating filter for classic wavefolder use
  • Works with complex signals like samples or drums for analog distortion effect

Controls & Jacks (14)

  • Subdiv ÷4— Gain control for the third subdivision output (÷4 octave)
  • Subdiv ÷8— Gain control for the fourth subdivision output (÷8 octave)
  • Subdiv ÷2— Gain control for the second subdivision output (÷2 octave)
  • Fold— Controls the amount of diode folding applied to the incoming signal, ranges from 0 to x6
  • Inject— Offsets the signal further to add more variations and harmonic content, with V and ^ markers indicating bipolar control
  • Subdiv ÷1— Gain control for the first subdivision output (÷1 octave)
  • Fold CV Atten.— Attenuator for CV modulation of the FOLD parameter
  • Out— Main output from the diode folding circuit
  • Subdiv Out— Output from the square & divide subdivision circuit with all active divisions mixed together
  • Inject CV Atten.— Attenuator for CV modulation of the INJECT parameter
  • Fold CV— Control voltage input for modulating the FOLD parameter
  • In 2— Second audio input jack to the folding circuit
  • Inject CV— Control voltage input for modulating the INJECT parameter
  • In 1— First audio input jack to the folding circuit

How-To Guides

  • Classic Sine Wavefold
  • Sub-Octave Layering
  • Subdivision Chaos Sweep
  • LFO-Modulated Wavefold
  • CV-Controlled Inject Offset
  • Analog Drum Distortion
  • Fold-to-FM Feedback
  • Z-DSP Delay Feedback Insert
  • Fold Before Filter
  • Dual Input Fold Mix

Explore the interactive FOLD panel on BleepDex — tap any control to learn what it does.

8c571ce