A pretty specific and weird, but interesting alternative is PureData, a sort of visual programming language where you can build your own "analog" synths and effects.

https://www.youtube.com/watch?v=s7Gv7SR0Nrk

It's very easy to get started, and extremely powerful. Not sure how well it covers your use case, but it's fun.

There's a great introduction to PureData called Designing Sound by Andy Farnell.