Embodiments of the present disclosure relate to methods and apparatus for peripheral device discovery, the detection of orientation of a connector having multiple degrees of rotational symmetry, and the provision of appropriate signal paths between a host device and a peripheral device. Some embodiments provide a characteristic impedance within the peripheral device that is coupled between rotationally symmetric contacts of the connector and thus enables detection of the connector orientation. The value of the characteristic impedance may be used in some embodiments to determine the type or model of peripheral device. Some embodiments are concerned with the enablement of appropriate signal paths to a peripheral device having a transducer (e.g. a loudspeaker) coupled only to rotationally symmetric contacts of the connector, such as headphones implemented in a "balanced" configuration.