The ARP 2600 is a semi-modular analog subtractive audio synthesizer, designed by Alan R. Pearlman with Dennis Colin, and manufactured by his company, ARP Instruments, Inc. as the follow-on version of the ARP 2500. Unlike other modular systems of the time, which required modules to be purchased individually and wired by the user, the 2600 was semi-modular with a fixed selection of basic synthesizer components internally pre-wired.