The ARP 2600 is beyond a doubt one of the finest analog synthesizers ever produced and it has been used in all genres of music with a lot of famous artists. The ARP 2600 is a unique semi-modular monophonic synthesizer that was designed for professional musicians, but was also user-friendly enough to be used as a teaching instrument. In fact the 2600 was used in a lot of college music departments and it competed directly against the Moog Modular synthesizer. The 2600 was ARP's answer to the modular system, creating a more compact, more stable and more intuitive synthesizer.

While most modular systems of the time were custom ordered and built to the buyer's specification, that flexibility often came at a high cost, both on the wallet and the brain. Instead of picking and choosing from a catalog of individual modules that you (or the manufacturer) then had to mount inside a case and wire together, the 2600 is a semi-modular system with a fixed selection of basic synth modules internally pre-wired and ready to go! Most of these connections can be "re-wired" with patch-cords at clearly labeled patch-points. This made the 2600 more user-friendly, portable and easier to create sounds with.

The 2600's basic architecture consists of a complete analog signal path with three oscillators, one 24 dB/oct filter, one ADSR envelope, one VCA and one mixer section. Additional features include an envelope follower, ring modulator, noise generator, LFO with sample and hold, built-in spring reverb and a pre-amplifier with stereo speakers.

The ARP 2600 was produced from 1971 to 1980 and the 2600 was built in four model generations, with each model being a little bit different, some with changes due to reliability issues, some due to legal issues, and some for cosmetic reasons. It's accepted that while the 2600s became more reliable and serviceable as their production progressed, they also got worse in the sound quality department, especially among models made after 1972. The best sounding models are the oldest ones and the most rarest.