It has two special oscillators, two envelopes and a special 2-pole dual filter. It works best when you set your VST host program to 96 kHz sample rate.
This is one of the best free VSTs out there. The sounds are incredible! I've used it in several of my songs. Velvet Strings is my fave! Thank you Land of Cockaigne!
Don't sleep on this one. It looks like one of the thousand other SE synths from the era but it used custom oscillators, filters and envelopes, and has a huge sound.
