AC power (alternating current power) refers to the type of electric power used to supply energy to the instrument from the main electrical grid. Most synthesizers, whether they are hardware or modular systems, require an external power source to operate, and typically, they use an AC power supply to convert the incoming AC voltage to the appropriate DC voltage levels needed by the internal components and circuits.
When connecting a synthesizer to an AC power source, it is essential to ensure that the voltage and frequency specifications of the instrument match those of the local electrical grid. Some synthesizers have built-in power supplies with voltage selectors, while others may require external power adapters or transformers to convert the input AC power to the appropriate DC voltage level(s) required by the device.
Additionally, the quality of the AC power can impact the performance and audio quality of a synthesizer. Clean and stable AC power is crucial for maintaining the integrity of the audio signal and avoiding noise, hum, or other power-related issues. In some cases, musicians and audio professionals might use power conditioners or voltage regulators to ensure a clean and stable power supply for their synthesizers and other audio equipment.