Eurorack Reference / modules /intellijel/bifold audit site v0.1 — milestone 3
intellijel/bifold

Bifold

Intellijel

Dual channel wavefolder combining a Buchla-style parallel 'deadband' folder (P channel) and a Serge-type serial folder (S channel), with a voltage-controlled crossfader for blending the two channels, plus CV inputs, feedback routing, and symmetry controls.504

Capabilities 2

Wavefolderwavefolder
Two independent wavefolder channels: P channel is a Buchla-inspired parallel deadband folder; S channel is a Serge-inspired serial folder. Both can be blended via a voltage-controlled crossfader.504
Waveshaper / Wavefolderwaveshaper
504

Jacks 9 — 6 in / 3 out

NameSignalVoltageDescription
Inputs (6)
AUX INmixed—When either SYM-X-AUX switch is set to AUX, the signal here is added to the input of the corresponding P or S folding circuit. If nothing is patched in, the MIX [C] output feeds this input (internal normal).504
FOLD P CV INcv-10V to 10VCV input accepting ±10V for externally controlling the amount of folding applied to the Parallel wavefolder. Internally normalled to +5V when nothing is plugged in.504
FOLD S CV INcv-10V to 10VCV input accepting ±10V for externally controlling the amount of folding applied to the Serial wavefolder. If nothing is inserted, the FOLD P [G] signal also feeds this CV input. If neither is patched, +5V is internally applied.504
IN Paudio—Input to the Parallel (P) wavefolder circuit. This circuit is a Buchla-inspired parallel 'deadband' folder.504
IN Saudio—Input to the Serial (S) wavefolder circuit. A Serge-inspired serial folder. If no jack is inserted into IN S, then the signal at IN P also feeds the Serial circuit.504
XFADE CV INcv-5V to 5VCV input accepting ±5V for externally controlling the crossfade between Parallel and Serial folders as heard at MIX [C] output. Attenuvertable via XFADE attenuverter [15].504
Outputs (3)
MIXaudio—Output of the mixed (crossfaded) Parallel and Serial folder circuits.504
OUT Paudio—Output of the Parallel wavefolder circuit.504
OUT Saudio—Output of the Serial wavefolder circuit.504

Parameters 12

NameTypeRangeBehavior
FOLDknob—Sets the initial amount of wavefolding applied to both the IN P and IN S folders. When set fully counterclockwise, no signal appears at any output unless CV is applied to FOLD P or FOLD S CV inputs. Positive CV increases folding, negative CV decreases it.504
FOLD P attenuatorknob—Attenuates the voltage at the FOLD P [G] CV input jack. Fully clockwise: all voltage is used to control folding. Fully counterclockwise: CV is fully attenuated. If nothing is plugged into FOLD P [G], internally normals +5V, so this knob acts as a 0V (CCW) to +5V (CW) attenuator.504
FOLD S attenuatorknob—Attenuates the voltage at the FOLD S [H] CV input jack. Works exactly like the FOLD P [13] attenuator knob but governs the Serial folder circuit instead.504
PHASEswitch—Inverts the phase of the Serial folder signal feeding the XFADE circuit, changing the sonic attributes at the MIX [C] output and enabling ring modulation when XFADE is centered.504
SYM-AUX Pknob—Attenuverter for the Parallel folder's SYM/AUX signal. In SYM position, attenuates a 5V DC offset voltage (affecting symmetry). In AUX position, attenuates the AUX [F] input voltage. Has no effect when the SYM-X-AUX switch is in the X position.504
SYM-AUX Sknob—Attenuverter for the Serial folder's SYM/AUX signal. In SYM position, attenuates a 5V DC offset voltage (affecting symmetry). In AUX position, attenuates the AUX [F] input voltage. Has no effect when the SYM-X-AUX switch is in the X position.504
SYM-X-AUX Pswitch—Three-position switch affecting the Parallel folder input. SYM (up): adds a DC offset of up to ±5V to IN P, affecting wavefolding symmetry; amount controlled by attenuverter [5]. AUX (down): adds the AUX [F] input to IN P (attenuated by knob [5]); if nothing patched to AUX, MIX output is used. X (middle): no external voltage added; input is symmetrical and unmodulated.504
SYM-X-AUX Sswitch—Three-position switch affecting the Serial folder input. SYM (up): adds a DC offset of up to ±5V to IN S, affecting wavefolding symmetry; amount controlled by attenuverter [6]. AUX (down): adds the AUX [F] input to IN S (attenuated by knob [6]); if nothing patched to AUX, MIX output is used. X (middle): no external voltage added; input is symmetrical and unmodulated.504
XFADEknob—Crossfades between the Parallel and Serial folder outputs (or their dry inputs, depending on XFADE P/S switch positions) as heard at the MIX [C] output. When summed value is 0V or negative, only P channel is heard; at +5V, only S channel is heard; between 0V and +5V, a blend of both channels is output.504
XFADE Pswitch—Two-position switch selecting the signal source for the crossfader's P-side (CCW) input. FOLD OUT P (up): the output of the Parallel folder feeds the P-side input. IN P (down): the input of the Parallel folder (dry) feeds the P-side input, enabling wet/dry mixing.504
XFADE Sswitch—Two-position switch selecting the signal source for the crossfader's S-side (CW) input. FOLD OUT S (up): the output of the Serial folder feeds the S-side input. IN S (down): the input of the Serial folder (dry) feeds the S-side input, enabling wet/dry mixing.504
XFADE attenuverterknob—Attenuverter for the XFADE [I] CV input. Fully clockwise: all CV voltage used for crossfading. Fully counterclockwise: full inverse value of CV is used. At noon position: XFADE CV is fully attenuated and does not affect crossfade amount.504

Firmware history 0 versions

No firmware history recorded.

References 2

  1. [504]
    Intellijel Bifold Manual (2021.08.15)manual
    source 504 canonical ↗ archived ↗
    ● verified 2026-05-19
  2. [505]
    Intellijel Bifold product pageproduct_page
    source 505 canonical ↗ archived ↗
    ⚠ verified 2026-05-19 · manufacturer changed since last verified