An audio signal is an electrical representation of, i.e., is analogous to, a sound waveform. The signal's voltage fluctuates in the same pattern as the speaker cone that reproduces it. Analog synths use oscillators, filters, amplifiers and other electrical components to create electrical signals analogous to the audio wave forms they are trying to represent.
Meaning of ANALOG in English
Guitar English glossary. Английский словарь гитарных терминов . 2012