Matthias Hermann is a long-time developer of (modular) synth modules. Besides designing and building new modules, he also recreates classics such as the Thomas Henry synth, or parts from succesful vintage synthesizers. More coverage of this DIY project(s) will be published soon.
Matthias writes on his website: “Rather a musician than an electronics engineer I was always looking for new sounds. This finally(?) led me to modular synth. Once I purchased some Doepfer modules for a modular guitar effect the plan rose to build my own modular synth… this was in 2005 and I never held a soldering iron in my hands before.”
On his website you will find a lot of PCB layouts, frontplate designs and building instructions. You can start building your own synth with all these raw materials, but you can also purchase modules through well-known retailers such as Thonk or Schneiders Buero.