Sosir Freeze-Delay is a free “experimental” plug-in for macOS (Intel/Apple Silicon) and Windows (AU/VST3), intended to give you bowing effects with guitar inputs. It’s beautiful for that, but also creates a range of freeze/delay effects, some beyond just the standard infinite reverb. Let the dark ambient drones commence.

Hat tip to SynthAnatomy for seeing this first. NUsofting has a range of free stuff amidst their other unique tools – see below.

Sosir is a stand-out. It’s a “virtual bow” that basically gives you a delay line with feedback, modulation, and freeze. You also get sub-octave doubling in the deal and dry/wet and filter controls.

I immediately set out to try this with AAS String Studio since I’m not a guitarist, plus some modified Ableton Live 12 devices, and of course a lift from some Sinevibes stuff. Here you go. I had to desaturate this, because it’s depressing:

The key note from the developer:

When the Delay Time is set to about the same or less than the “arcata” duration, the repeats (by delay feedback) would merge in a long sustained sound, this makes it sound more like the infinite reverb you
know.

Grab it here:

https://nusofting.com/fertile

And find more freeware from them:

https://nusofting.com/plugin-category/freeware

More examples of this in action, used a lot more as intended:

And more of their other free plug-ins: