--- In
AN1x-list@yahoogroups.com, "Mark Daborn" <darkest.yugo@n...>
wrote: Is there anyone who can help explain to me what a "Self-
Resonating" oscillator is and why the random LFO setting is
called "Sample and Hold" ?
> Maybe you mean a self-oscillating filter? On some filters if you
crank the resonance up all the way, it will oscillate. You then can
adjust the pitch with filter cutoff to tune it. Usually need to turn
level of filter down to avoid speaker/ear damage! "Sample and hold"
goes back to the days of voltage-controlled analog synths. Waves
generated by the oscillators ( or white noise) usually had a signal
strength of 0 to 10 volts. A waveform input is "sampled" by a pulse
signal which produces a voltage corresponding to the point on the
wave that was sampled. The voltage produced is then "held" at that
point until another pulse signal samples the incoming wave's voltage.
If the input signal is white noise, the output will be a random
voltage pulse. Sampling rate is controlled by an internal clock (
knob usually marked in hz like an lfo - 1hz to 1000hz for example.)
In Voltage-controlled analog synths, a random voltage can be used to
modulate pitch, filter cutoff, or just about anything else.