NUSofting has released Mac AU/VST3 versions of the freeware effect Sosir Freeze-Delay. The 64-bit VST3 for Windows is available at the same page.
The idea of Sosir was to create a bowed sound (by freezing the input) from a plucked sound (roughly speaking: guitar pluck to bowed strings).
There are two stages:
- Digital virtual bow.
- Delay line with feedback and modulation by LFO.
There is also a small reverb at the end, but that's optional.
Use the "Sound Choice" selector to change the base timbre and duration of the bowed sound. Then you have the other controls to adjust it to your needs: "bow" dry/wet, sub octave doubling, filters LowPass HiPass.
When the delay Time is set to about the same or less of the "arcata" duration, the repeats (by delay feedback) would merge in a long sustained sound, this make it sound more like the infinite reverb you know.
Note. That there are two different "Wet" controls: the mix of "bow" effect and the mix of delay effect.