Unbalanced audio refers to a type of audio signal connection that uses a single conductor to transmit the audio signal, along with a ground reference. This type of connection is more susceptible to interference and noise, particularly over longer cable runs, when compared to balanced audio connections.
In modular synthesizers, unbalanced audio connections are commonly used due to their simplicity and lower cost. The most common types of connectors used for unbalanced audio in modular synths are 3.5mm (1/8 inch) or 6.35mm (1/4 inch) TS (Tip-Sleeve) connectors. The tip of the connector carries the audio signal, while the sleeve serves as the ground reference.