Did mess about with something that more follows the actual bass, but sounds like you don't need it now. Here it is anyway if you want to mess about;
There's also a bit on the end where I foolishly attempted to play it in 16ths...
Sounds like something from 1980s Iron Maiden... Interesting through the Guitar Rig 'Harmonic Synthesiser' though - bit 70s...
...one for another day..