[Septillion] and [Hugatry] have come up with a hack to manipulate a USB charger into becoming a variable voltage source ... simplify the control of the power supply. The video below shows ...

FlexPower FPO150/250-E2 power supply with 230 V AC input voltage FlexPower FPO150 offline switchmode power supply-battery charger FlexPower FPO75 offline switchmode power supply-battery char - ger ...

D’Addario has launched the XPND Pedal Power Battery Kit ... lengths to connect your pedals to your power supply. If you want something adjustable, then the aforementioned daisy chain system ...