Amazon.com: Security-01 AC to DC 18V 1A Power Supply Adapter,Plug 5.5mm x 2.1mm,Center Positive,UL Listed FCC,XH1800-1000w,Compatible with for 18volt 100mA-1000mA Equipment : Electronics
Amazon.com: 18V Negative Center Power Supply AC DC Adapter for 18V Guitar Effects Pedals, 18VPDL : Musical Instruments