Vult Nitrous is out. This is my TB-303 filter model. It was modeled after my own 303 prototype. With this filter I think I have achieved a very good compromise of accuracy vs performance. Nitrous stands out very well against the A-103 from Doepfer because the filter circuits are very similar.
A few technical details for the nerds. This is (practically) a 18dB/oct filter. Even when it features 4 poles that should make it a 24dB filter, one of the poles is at a higher frequency than the others. When measuring the slope around the cutoff frequency you can see that it is 18dB.
This update features as well a few bug fixes. The most important is a bug that introduced a bit of noise in Lateralus. This was caused by the tolerance of my solver. A lower value of tolerance produces a more accurate simulation but also means more CPU usage. So now Lateralus consumes a little bit more CPU.