Conventional instruments exhibit more `life' and variation in tonal character than electronic instruments due to the way in which they are played. For example, string instruments and woodwind instruments can exhibit marked tremolo and/or vibrato due to variations in the bowing or blowing. The keyboard of a synthesiser provides a relatively inflexible and expressionless means of playing that does not allow these nuances to be introduced into the sound, and in order to make the sound more `lively' amplitude and frequency modulation must be introduced using LFOs and noise sources.

The ASM320 is a classic LFO design enhanced with the addition of voltage control and a [RESET] input. There are 2 different frequency ranges:-

1. HI - with a range from around 40Hz down to over 1 minute per cycle
2. LO - with a range from around 6Hz down to over 3 minutes per cycle

The [RAMP] and [SLOPE] outputs run at twice the frequency of the [SQUARE] and [TRIANGLE] outputs.

The [RESET] input allows the VC LFO output to be 'reset' to start again from 0V. It will continue in the direction that the slope was changing when the 'RESET] was applied.

The [CV] input allows the output frequency as set by [RATE (f)] to be increased to roughly double.