so my question is pretty straightforward: what are the ways in which this circuit is likely to fail, and how can I protect against that?
I play music (mandolin and viola) and my instruments have piezoelectric pickups, which sound kind of crap connected directly to a mixer.
I've built this buffer circuit (see image) and it works - my instruments sound significantly better. I intend to build it into a module for my instruments for use while performing live.
It is my impression that, because this circuit is so basic there shouldn't be much that can go wrong. Feel free to disabuse me of this notion - but please explain why as I wish to get a clear understanding of what I'm missing.
EDIT 1: I also attempted to measure the current draw, but it's so low (well under 10mA) that my cheap multimeter couldn't measure it, and the 5V USB power bank I was using to power the circuit kept powering down. For this reason, I presume that the voltage levels will generally remain stable during use ... is that a safe assumption?
EDIT 2: Updated circuit design based on suggestions from @richardthespacecat and @analogsystemsrf