There are a few different modular synth standards in existence but by far and away the most popular one is Eurorack. First standardised by Dieter Doepfer in 1996, his decision to make the specification freely available helped create the dizzying array of innovative brands and modules that we see today. Cheers Dieter! We also stock a selection of Buchla format devices if you want to travel down a different musical path.
Tiptop Audio