Monday, 1 August 2011
Patch Tips#16 - Analogue Logic
Using the A-172 Min/Max as a voltage limiter.
Today's Patch Tip is taken from this discussion on limiting the output of a Wiard Noise Ring. Self Oscillate's suggestion of using a min/ max module is a simple but ingenious solution that deserves re-posting. Not only can it be used to limit the level of a stream of CVs, applying a threshold in this manner can also clip audio waveforms, dynamically if desired.
"… feed the NR output to a max/min module, together with a fixed voltage which determines the highest allowed pitch. then use the min output. the higher notes will not exceed the fixed voltage, while the lower notes get through unchanged."
As Self Oscillate notes, the benefit of using a min/max module is that, unlike general attenuation, the lower CVs are unaffected. When applied to audio, this results in a 'squaring-off' of the waveform at a pre-determined level. Experiment with the A-172's outputs for positive and negative clipping.
I'd previously used the A-172 and Maths' OR output to trace the peak contour of two sources, but hadn't considered doing the reverse. Thanks to Self Oscillate for this useful application of fuzzy logic!