Liquid discharge apparatus and head unit

A liquid discharge apparatus comprising:

• a head unit that discharges liquid;
• and
• a digital signal output circuit that outputs a digital signal to the head unit, wherein
• the head unit includes
• a plurality of print heads that discharge liquid, and
• a housing that houses the plurality of print heads,
• a first print head in the plurality of print heads includes
• a substrate that includes a first side, a second side which intersects with the first side, a first surface which has the first side and the second side, and a second surface which is different from the first surface,
• a first nozzle plate that includes a first nozzle row in which a plurality of first nozzles for discharging the liquid are provided in line in a direction along the first side,
• a connector that is provided in the first surface and to which the digital signal is input,
• a first integrated circuit that is provided on the first surface, that is electrically coupled to the connector, to which the digital signal is input via the connector, and that outputs an abnormality signal indicating presence or absence of abnormality of the first print head,
• a first flexible wiring substrate that is electrically coupled to the substrate, and
• a second integrated circuit that is provided on the first flexible wiring substrate,
• the second integrated circuit is located between the first nozzle plate and the substrate, and
• the substrate is provided so that the first surface faces downward and the second surface faces upward in a direction along a vertical direction.