A synth which is programmed with a set of patches at the factory, with little or no capability for the user to edit or store changes to the factory patches. Most electric organs and digital pianos can be regarded as present synths. A range of preset synths were produced in the 1970s as a work-around to the problem that the technology of the time made the construction of polyphonic synths very expensive. Manufacturers realized that by replicating certain basic circuit blocks, they could build a polyphonic synth capable of producing a small, limited set of sounds, and so they built units producing sounds which performers of the day most wanted in a polyphonic unit (mainly string and piano sounds; see also string synthesizer). These types of designs went by the wayside in the 1980s when technology improvements made general-purpose polyphonic synths more affordable.