This patch generates a Shepards tone.
The 8 oscillators are modulated in frequency by 8 phase-shifted sawtooth LFOs (1/9*360 to 8/9*360 degrees)
To fade the VCOs in and out, I’ve used 2 methods that can be switched with the switch44:
1: 8 triangle LFOs, offset to have a voltage of 0-10V, with the same phase relationship as the LFOs controlling the VCOs are used to control the volume of each oscillator. It starts at 0 when the VCO frequency is at its minimum, goes up and down and ends at 0 when the VCOs frequency is at its maximum.
2: The VCOs are bandpassed quite strongly (12 pole filter!) between 100Hz and 5kHz, taking care of fading the VCOs in and out.