Rob Tsou is a partner in Alchemy Yo-Yos, which started in 2007 along with modders Eric Wolff and Radiyoactive's Jaco Greeff. Tsou has been active in the modder scene within the yo-yo community, and has given workshops at the World Yo-Yo Contest for many years. This is what eventually led Tsou to his partnership with Eric Wolff, Jaco Greeff and their development of Alchemy.