Essentially a 1972 performance/portability refinement of the lovingly designed VCS3, the Synthi AKS added a 30 note non-moving keyboard sequencer to the basic VCS3 synthesizer specs. That is why this suitcase synth is coveted by noise freaks and sound junkies the world over. I must say that I love the pin matrix as well, with its ease of use and visual clarity. My Synthi had a few mods done (by EMS guru, Robin Wood?) to it by a previous owner, but I seldom use them. The sounds that this thing makes out of the box seem more than enough to me. A keeper for sure!