Airwindows has released Slew2 for Mac OS X and Windows, a free plug-in in AU and VST formats.
Here's what Airwindows (Chris Johnson) says:
"This plugin is just the anti-aliasing technology I was experimenting with in 2010, applied to Slew, my simple slew clipper. I thought it was going to make the slightly grungy Slew smoother (Slew is a clipper, and can be expected to have clipper-like qualities). That anti-aliasing code was a bit odd. It's possible I made a mistake somewhere."
"If so, I'm keeping it, and now what I invented is out for VST also, and free to all."
Slew2 doesn't act anything like Slew. What it does, is it puts a particular behavior on the extreme highs. Set to an intermediate value, it's an acceleration limiter. Cranked all the way up... well, check out the video. It behaves like one of the nodes in Average (also coming to VST) with a 100% cancellation, but the point of total cancellation is also the Nyquist frequency. Slew2 produces a very natural-sounding brickwall filter exactly at that frequency, with the response falling off faster and faster until it's totally gone when you hit the Nyquist limit (digital sampling theory: at 44.1K (CD quality) it is 22.05K where the treble cuts off).
People are using this for de-essers, and it's pretty much ideal for any sound that must not be overwhelming in the super highs. The peculiar character of the rolloff means it's suitable for almost anything because it won't affect lower treble, and the fact that it's really a clipper means you can use the slider to set a thresholdwhere, the harder you push Slew2, the more it'll refuse to let more brightness through.
Many Airwindows plug-ins are now free and you can support Chris via Patreon.
Airwindows plug-ins released this year include: