2500 Modular
Unveiled in 1970 under the name, Tonus, Inc., this was ARP's first synthesizer. Modular in design, it uses [color-coded] sliders for patching, doing away with other modulars' messy cords. However, the sliders introduced problems with cross-talk. [Where patch cords are necessary, and they are for some things, the 2600 uses mini-jacks, not 1/4-inch] It was available in custom configurations. Along with Philip Dodds [ARP vice-president of engineering], the 2500 made a cameo appearance in Close Encounters of the Third Kind (1977,1980), where it helped man communicate with the visitors from outer space through music and mathematics.