https://www.noisebud.se/?page_id=103
Burt are built around a traditional chain of subtractive synthesis but Instead of the traditional way with a nice and clean signal chain Burt adds distortion or exaggerate the signal in every step of the signal path. So even if you start off with a clean sine wave you might end up with something completely different and might even not hear any difference if you change to a saw or square. But be sure of one thing; it will sound like no other synth you heard before!
Call it waveshaping or oscillation by distortion if you like… We call it Burt!