Daedalus 0-100V PWM DC Power Supply Motor Speed Controller Switch 6A, Mach3 Supported https://smile.amazon.com/dp/B07ZSXGYXL/ref=cm_sw_r_apan_glt_fabc_3NXFZNGASYPB9DQ5X6B6?_encoding=UTF8&psc=1 I used this one. Just adding a power supply will not control speed without either PWM control or a potentiometer. This will do both. I am using a different board from the stock one so I don't know if the stock board will control speed through this but if not you can use the potentiometer (knob) that comes with it.