User`s manual

Page 28
Voyager OS User’s Manual - The Components
Page 29
Voyager OS User’s Manual - The Components
G – The LFO
The Voyager OS has a dedicated Low Frequency Oscillator (LFO). The LFO produces triangle and square
waves as well as stepped and smoothed Sample & Hold (S&H) signals over a range of approximately 0.2 to
50 Hz. The LFO signal is available as a modulation source on both Mod Busses.
For the Sample and Hold circuit, the LFO’s square wave is used as the S&H Trigger
input, while the Voyager’s Noise source is used for the S&H Input signal. For each
positive-going cycle of the LFO square wave, the voltage at the input of the S&H
circuit is sampled and held until the next cycle. Since the sample source is Noise
(a random signal), the voltage that appears at the output of the S&H circuit is a
random voltage that changes in time with the LFO.
The Voyager’s CV Interface jacks on the back panel of the Voyager allow additional
 exibility with the Sample and Hold circuit. For example, if a plug is inserted into
the S&H Gate input, it will disconnect the LFO trigger; an external gate signal can
then be used to trigger the S&H circuit. Similarly, a plug inserted into the S&H
Input jack disconnects the Noise source from the S&H input. In this circumstance
when the S&H circuit is triggered, the voltage at the tip of the plug is held at the
output of the S&H circuit. This makes it possible to get interesting modulation
patterns such as the ‘staircase’ modulation shown below.
The Voyager’s Sample and Hold circuit can
create more than just random signals –
interesting stepped modulation patterns
are also possible.