H. G: Fortune has released STS-21 Pro, a completely reworked version of the original STS featuring the "eXTended Wave-Transition" method plus "X-Torsion" for unique atmospheres, soundscapes, pads & textures. It features a straightforward user interface with 3 "Lazy"-Buttons for randomizing different sets of parameters.

Features:

• Four digital PCM-wave oscillators powered by 120 (Pro) / 78 (free) selectable waveforms.
• X-Torsion function for oscillators.
• Two "Transit(ion)"-modes.
• Two resonant filters (24db Lowpass and 12 db Highpass).
• Three ADSR-style envelope generators.
• Two LFO (BPM-synced).
• One LFO with shapeable and even pattern like waveforms (BPM-synced).
• One Sample & Hold (BPM-synced).
• One LFO (BPM-synced) for alternate Transition mode.
• Combined LFO as mod-sources for filters.
• Stereo delay.
• Stereo Reverb.

A two voice free version is supplied with 256 patches (1 internal and 1 external bank) - a selection from the whole sets.

Extra features of the Pro version:

• Additional internal and external banks as there are more waves inside. Presets were done by Vera Kinter (VK), Annabelle (ANN), Dimitri Schkoda (DS or no sign), Aron Elvar (AE), Phil Garrison (PG) and HGF.
• Incorporates loading of User Soundfonts & wave files (up to 24 Bit).
• More voices.
• Incorporate 30 waveforms from the STS-17.
• The Pro version will be updated (the free version won't).

The Pro version costs €29. The free version is available for download.