The POLY555 is the newest DIY analog synth from Oskitone, creator of the OKAY synth.

The POLY555 Kit: https://www.oskitone.com/product/poly555-synth-diy-kit POLY555 Blog post: https://blog.tommy.sh/posts/poly555-synth/ POLY555 assembly guide: https://oskitone.github.io/poly555/