I’ve been playing around with Softube’s virtual copy of the Buchla 259e Twisted Waveform Generator and I got curious about the wave folder. I found the following paper: http://www.dafx17.eca.ed.ac.uk/papers/DAFx17_paper_82.pdf
A diagram in the paper led me to building a wavefolder using a spline node. I didn’t attempt to reduce the inevitable aliasing, but I think it has a interesting character. In the original hardware, the folder is driven by a sine wave, but I thought this might be more flexible. I also added a cross-fade with the unfolded wave since at a fold level of 0 there is no output from the folder. It’s a bit of a kludge, but it sounds OK.
I’m hoping to eventually be able to recreate these drones using Audulus:
07/25 Version 2.0 removes the cross fade and adds multiple folders. An “order” control crossfade between 4 different folders with increasing folds.
||higher amplitudes cause more folding|
||controls the symmetry of the output waveform - 50% is symmetrical|
||controls the number of folds (V2.0 only)|
||controls both the folding amount and the crossfade|
|2.0||Wave Folder V2.0.audulus (34.8 KB)||07/25/2019||added order control and revised folder scaling|
|1.0||Wave Folder V1.0.audulus (8.7 KB)||07/24/2019||initial upload|