A light output device comprises a substrate arrangement comprising a plurality of light source circuits integrated into the structure of the substrate arrangement. Each light source circuit comprises a light source device arrangement (4) having two terminals and a transistor circuit (7). Each light source circuit is supplied with power from an associated pair the power connections (10,11,14,15,20), and at least two light source circuits (4,7) share the same pair of power connections. A set of control connections (18) are provided for receiving external control signals for controlling the transistor circuits (7). A set of non-overlapping electrodes (10,11,14,15,18,20) provide the internal connections between the power connections, the light source device terminals and the transistor circuits, and each light source device is individually independently controllable.