How do I increase the volume on my zansa clip+?
The volume control rocker is on the side of the device.
Seriously though, this little guy puts out plenty of volume by itself. So much so that the EU determined it can be detrimental to your hearing, so they instituted a maximum level. But then, if you read the rest of this thread you already know that and the workaround in case you are affected by it.
The only other way to “pump it up” would be to use a headphone amp. Be careful though, hearing loss happens gradually over the course of several years, and you can never get it back.