FPAAs don't really exist as products you can buy, as far as I know (unlike FPGAs, which are a very mature technology to the point that I suspect there's nontrivial (say, >5%) odds the average HN reader owns something with a FPGA in it somewhere.))
I didn't know about this. It's curious that the article mentions that recently (2016) improved FPAAs were demonstrated. Perhaps an opportunity where there wasn't one before.
I wonder how difficult it would be to re-purpose a modular analog audio synthesizer for this. Since they're direct descendants of analog computers in the first place.
There are ASICs out there that simulate analog synths, such Universal Audio. Brings to mind some interesting pure software approaches if that were the case.