Metasonix

Metasonix is a brand of analog synthesizers and audio processors known for their unique, vacuum-tube-based circuits. The company was founded in 1999 by Eric Barbour and is based in California.

Not DIY
Metasonix has not officially offered any DIY products or kits. However, Eric Barbour has published schematics and technical information for some of his designs and some enthusiasts have used this information to build their own versions of Metasonix modules or modify existing ones.