Generating Random Values in the Solo Synth

[AlenK]

Here is a technique to generate a random value for use in modulating parameters of the solo synth and which holds for an entire note. Each subsequent note gets a new random value. This is quite different behavior than the Random waveform offered by the solo synth’s two LFOs. When the Random waveform is used the LFO generates two random values within each cycle; one holds for the first half of the cycle and the other holds for the second half. 

To generate our random value both of the solo synth LFOs are needed as well as a virtual controller. Choose the Random waveform for LFO1. Set the Rate to exactly 126. The setting of the Depth parameter is up to you; it determines the total range within which random values from the LFO will occur. For LFO2 choose one of the pulse waveforms. Set LFO2's Rate and Rise to zero and set the Delay to 001. Set the Depth of LFO2 to 127. In a virtual controller choose LFO2 as the source and the Rate of LFO1 as the destination. Set the depth of the virtual controller to -128. 

With this arrangement pressing a key allows the Random waveform to cycle between values very rapidly. But after a short delay of about 1/16th of a second (roughly 60 milliseconds) the virtual controller forces LFO1's rate to zero, at which point the last random value it output is held until you press another key while no other key is being held. 

Unfortunately, the required minimum delay time still allows the random value to change during the small interval that LFO1's rate is not zero. So there will often be a quick transition ("blip") between two random values at the very start of a note. (Lowering the rate of LFO1 does not appear to help.) Consequently, try to apply this technique to a parameter that is not audibly affected by the “blip.” Also, tones with attack times of 007 or longer on their volume envelopes will effectively mask it. 

An example file is available here. All it does is modify the pitch of a single oscillator with the random value. In practice the value would be used to modify something more useful, such as filter cutoff or, by using another virtual controller, attack time.