“DC coupled” refers to a type of input or output connection that allows both AC (Alternating Current) and DC (Direct Current) signals to pass through it without any attenuation or filtering.
An AC signal is a time-varying voltage, such as audio signals or modulation sources like LFOs and envelopes, while a DC signal is a constant voltage level that does not change over time, often used for control voltages or offsets.
A DC-coupled connection can handle both types of signals, which is particularly useful in a modular synthesizer environment, where users may want to process, mix, or modulate various signal types. This means that a module with DC-coupled inputs and outputs can process and transmit both audio and control voltage signals without any restrictions or loss of signal integrity.
In contrast, an AC-coupled connection uses a capacitor to block DC signals, allowing only AC signals to pass through. This type of coupling is often found in audio processing modules where DC offsets might cause unwanted artifacts or distortion.