- Eventide Audio

Home Forums Products Vsig and Preset Development Oscillator and LFO waveforms. Reply To: Oscillator and LFO waveforms.


You’ll find SLFO is even better to make a barberpole effect.  If you investigate one SLFO set to be a master, you’ll see the sync output signal is a bipolar ramp or sawtooth (from -1 to +1).  Then each SLFO set to be a slave receives that sync signal and treats it like the timing belt on a car engine.  One cycle of the master SLFO is like one turn of a car engine crankshaft, and the slave SLFOs respond with one cycle of whatever they are programmed to do, like camshafts opening and closing the engine valves.  You can program the slave SLFOs to have the desired phase relative to the master (e.g., your 0, 45, 90, 135, 180, 225, 270, and 315 degrees).  You can “hard-code” those values of relative phase into the slave SLFOs in VSIG (and not worry about tweaking them from the front panel).  Then what you will find very interesting is patching the master SLFO frequency to a KNOB on the front panel:

  • Dial the master frequency positive — your barberpole goes up.
  • Dial the master frequency to zero — your barberpole stops.
  • Dial the master frequency negative — your barberpole goes down.

I would break the project into two studies:

1) VSIG files to practice using SLFOs to make ramps you can see on the screen (using HMONITOR can show eight on one screen), and

2) VSIG files to check how your ear hears audio effects driven by LFOs.  The VSIG phase shifter module is an all-pass filter (flat in frequency by itself), and it needs to be combined with another signal path to make peaks and notches in frequency that we can hear.