Since the invention of the pulse tube refrigerator, improvements have mainly focused on developing new phase shifters, while the basic structure of the cold head is not changed much. With the combining of step piston pulse tube refrigerator with thermoacoustic refrigerator, a new concept called resonator pulse tube machine is proposed. It is investigated by a numerical simulation, which shows that it can work as a refrigerator or a cold engine depending on the swept volume ratio of the step piston compressor. (C) 2017 Elsevier Ltd. All rights reserved.