Update on finding my sound: I couldn't quite get the ooomph out of my Jazz, I'd fiddled with amp settings, the knobs on the bass etc. Sometimes it would sound great at home , but with the band it would fade away or just sound ropey.
A new set of D'addario nickel strings and the bass has twice the output, twice as much bass, twice as much trebble and 99% more va va voom.
Best £18 I ever spent.