Timo Rozendal USB Powerthingy (Euro Power Supply)
$6.00 - $49.00
maximum current: 1.8A (and the 5V usage will be added to this)
maximum output current: +12V is 700MA, -12V 150MA
synthCube kit includes everything you need- including the DC-DC step-up module
These kits and assembled modules are offered on demand, click the link to learn more.