Liquid ejection apparatus and liquid ejection head

A liquid ejection apparatus comprising:

• an ejection portion including a piezoelectric element driven by a drive signal, a pressure chamber filled with a liquid and having a volume that changes according to driving of the piezoelectric element, and a nozzle ejecting the liquid in the pressure chamber according to a change of the volume of the pressure chamber;
• a first wire to which a first drive signal of the drive signal is supplied;
• a second wire electrically coupled to an element electrode of the piezoelectric element;
• a detection circuit detecting a potential of the element electrode varying according to a vibration remaining in the piezoelectric element after the driving of the piezoelectric element;
• and
• a check device checking an ejection state of the liquid in the ejection portion based on a detection result of the detection circuit,
• wherein the detection circuit includes a first amplifier circuit, and the first amplifier circuit includes
• a first amplifier having a first input terminal, a second input terminal, and a first output terminal outputting a signal based on input to the first input terminal and input to the second input terminal,
• a first resistor electrically coupling a first node electrically coupled to the first input terminal and a second node electrically coupled to the first output terminal, and
• a second resistor electrically coupling the first node and the second wire, and
• the first wire is electrically coupled to the second input terminal.