Review on 🔌 DROK USB Cable DC 5V Boost to 9V 12V Step Up Voltage Converter 1A, USB to 9v/12v Step-up Volt Transformer Power Regulator Line with LED Display by Non Dollarz

I wanted something that would power my guitar pedalboard with a simple battery powered USB connection so I could play anywhere without worrying about an outlet . Serves its purpose fully and is durable. I glued a 9V/12V switch to the 9V position so I wouldn't accidentally over-voltage my pedals, and for this application you'll need a connector to reverse the polarity of the output connector. I also have a connecting cable to connect multiple pedals to the same power supply. It produces a very smooth output voltage. The only issue I had was that one of my USB battery packs was emitting an audible hiss on the output that this power supply didn't filter, but it was the battery pack, not this source. Works great and is worth the money!