Rats, almost missed a very cool project. Only three days and unfortunately just below the funding limit. Yesterday we had a guitar that allows to play amplified without an amplifier. Ripcord goes another way.
Guitarist (and other musicians) who work with pedals or other tool with 9V power will know the problem. Batteries are always empty and if one wants to take a PSU it usually entangles with the cables, you need distribution and so on. Has always annoyed me.
Too bad that most USB-Power Banks works with 5V. It would be fine if you could use them. Here Ripcord comes into play. This small cable claims to that it can transform 5 V from a power bank or a smartphone to 9V. That would be really cool. It allows to get a small amplifier, walk to the mall and earn the 14 € for such a cable with your music..