The Spiratone music synthesizer module is a form of Shepard Tone generator. It is a sonic barber pole that creates the auditory illusion of a tone that continually ascends or descends in pitch, yet ultimately seems to get no higher or lower.

It occupies the same space as the tELHARMONIC. To find it, have nothing patched to D-Gate and HOLD H-LOCK for 5 seconds. The sound will dramatically change... you've found the Spiratone inside your tELHARMONIC.



  • Multi Voice Shepard Tone generator inspired by Jean-Claude Risset "Computer Suite from Little Boy: Fall," 1968 & James Tenney "For Ann (rising)," 1969

  • CENTROID sets spacing of the oscillators

  • INTERVAL allows for complete control of modulation depth and direction

  • FLUX adds random pitch fluctuations

  • ∞ octaves of continuous 1V/ Octave pitch control

  • ∞ octaves of quantized pitch control

  • DEGREE Modulation able to be synchronized by clock or gate via D-Gate input

  • Gate Out completes the conversation between Spiratone and rest of system!

  • Utilizes High performance DSP hardware with 24bit, 48kHz codec, 32 bit floating point processing

  • Reasonable power consumption

  • Pairs well with Optomix