The System 100 is a great and classic analog synth! It's a beautiful semi-modular monophonic synth consisting of 5 module components: the Synthesizer 101, Expander 102, Mixer 103, Sequencer 104, and Monitor Speakers 109. The Synthesizer 101 section is the heart of the system, from which you could add-on any of the other modules of your choice. Different combinations of these components can be used to create systems of varying potential.

The Synthesizer 101 section is a fully self-contained analog mono-synth. It features a 37-note keyboard (with no performance controls, velocity or aftertouch), and lots of sliders to tweak. Its design is similar to the SH-series analog synths. Controls for the VCO, LFO, VCF lowpass/highpass filters, VCA with ADSR, Noise, and Portamento/Glide effects are all within hands reach. There's also a handy A-440Hz tuning oscillator, like on the Minimoog.

The Expander 102 section is a keyboard-less version of the 101, designed to stand upright and behind the main Synthesizer 101. More than one Expander 102 can be added to make your system fatter and fatter! The Expander is identical to the Synthesizer except that it replaces Portamento/Glide effects with a Sample-and-Hold feature for the LFO, the Noise gen. is replaced by a Ring Modulator, and the A-440 tuning osc. is replaced by weak/strong sync inputs and a mix-in jack. The Expander is an excellent way to add more oscillators and synth effects (the s&h and ring-mod) to a System 100. The oscillators can be synced if you have both modules. The 101 & 102 are already internally patched and ready to produce sounds, but that can be bypassed by external patching.