18v 5A DC or bigger to 48v should not injury the amp. *I am not sure of your 18v least encouraged amperage rating for your chip, but 3A or even more should really operate. ryanmh1 explained: EDIT: Latest products are "terrific" or "superb" by the "most people Never hear it" https://localtailor.net/California/Displays-&-Holders-Charters-6075216