Analog synthesizer
After the 1960s, analog synthesizers were built using operational amplifier (op-amp) integrated circuits, and used potentiometers (pots, or variable resistors) to adjust the sound parameters.
The earliest mention of a "synthetic harmoniser" using electricity appears to be in 1906, created by the Scottish physicist James Robert Milne FRSE (d.1961).
They were generally "modular" synthesizers, consisting of a number of independent electronic modules connected by patch cables into a patchbay that resembled the jackfields used by 1940s-era telephone operators.
Because many of these modules took input sound signals and processed them, an analog synthesizer could be used both as a sound-generating and sound-processing system.
In 1970, Moog designed an innovative synthesizer with a built-in keyboard and without modular design—the analog circuits were retained, but made interconnectable with switches in a simplified arrangement called "normalization".
In the 1970s, miniaturized solid-state components let manufacturers produce self-contained, portable instruments, which musicians soon began to use in live performances.
The first movie to use music made with a (Moog) synthesizer was the James Bond film On Her Majesty's Secret Service in 1969.
The Polymoog was an attempt to create a truly polyphonic analog synthesizer, with sound generation circuitry for every key on the keyboard.
However, its architecture resembled an electronic organ more than a traditional analog synthesizer, and the Polymoog was not widely imitated.
By the early 1990s, however, musicians from the techno, rave and DJ scenes who wanted to produce electronic music but lacked the budget for large digital systems created a market for the then cheap second hand analog equipment.
In addition, despite the widespread availability during the 2000s of relatively inexpensive digital synthesizers that offered complex synthesis algorithms and envelopes, some musicians are attracted to the sounds of monophonic and polyphonic analog synths.
