Chordal Ambient Tape Delay Patch

Core Techniques:

  • Harmonic chord progression using Harmonàig/Saïch
  • Cascaded pitch shifting delay
  • Sub-harmonic waveshaping with through-zero frequency modulation
  • Rhythmic textural “bird noise” by oscillator cross-modulation

This is quite a dense patch with a lot of subtle modulation and some interesting waveshaping techniques involved. Fundamentally it is a patch using 3 parallel voices as audio sources which are mixed via multiple crossfaders.

The primary voice is the harmonic aspect which utilises a Saïch controlled by a Harmonàig to define the chord progression basis of the composition. The Harmonàig can either be controlled via CV for preprogrammed/randomly self generated progressions, or can be manually played in Performance Mode. When a new Root note is defined, the GATE output controls the Cèis ADSR which triggers a cascade of events that influence the patch. The Cèis envelope output (acting as an AR) sounds the chords through a VCA which routs to the Lúbadh, which is configured as a tape delay.

Various gate and trigger signals from the Cèis clock two S&H modules as well as toggling signal routing for variations in parameters such as interval offsets on the Saïch (which introduces tension tones to the chords), input mix of the Saïch voice between the Lúbadh’s decks and varies the index ratio of the Cš-L’s complex voice.

There is a parallel bass voice which follows the root of the Harmonàig chord progression and is triggered by the primary voice’s ADSR envelope (Cèis). The tone is produced by the trigger output striking/pinging the I-ō47 filter which is tuned to match the Root of the Harmonàig voice. The percussive tone from the Band Pass output is waveshaped via a tanh[3] channel to restrict its amplitude and add a bit of saturation to the timbre. This signal then modulates a neóni configured in TZFM configuration to act as a waveshaper over the tone.

The High Pass output is converted to an aggressive unipolar positive square wave signal via the AND gate of the eãs. This signal is used in parallel to the TZFM waveshaping to soft sync the neóni at the audio rate of the Root note frequency. This clock signal patched to the soft sync input is toggled on and off via a latching switch (tàin) controlled by the release stage gate output of the Cèis. The result when the soft sync is engaged is a sub-harmonic introduced to the voice. As the voice is triggered at each segment change of the ADSR this gives a longer rhymic meter that nicely matches the harmonic rhythm of the composition.

Finally, there is a generative textural voice which sits in the higher frequency bandwidth to serve as a chaotic percussive element somewhere between hi-hats and bird noises. This comes from a self modulated Cš-L. The sine wave of oscillator B is used as the sound source. The resulting tone is gated through a VCA by the OR logic result of oscillator A’s PWM voice (inverted at the eãs ~ gate) and the clock pulse of the Lúbadh’s left deck. The Lùbadh clock is the stable element in this gating signal as the Cš-L is fundamentally unstable due to extreme cross-modulation.

The cross-modulation is exponential on both oscillators and the wavefolder of oscillator B is used to modulate oscillator A which is in LFO range. The wavefold depth of oscillator B is modulated in addition to the FM depth via the INDEX control.

For final seasoning, an øchd is used to add additional movement to the patch keeping things more dynamic. Vibrato is added to the Saïch voice using the first LFO from the øchd tunes to ~4-5Hz. This vibrato naturally softens the the voice as it is reverberated and echoed in the Lúbadh.