[quote name='MoominGiant' post='722865' date='Jan 24 2010, 09:38 AM']The bass I've got is a Hohner Rockbass. It's got quite a bit of fretbuzz on a couple of the strings, the tone control doesn't work and fiddling with the volume control normally causes the signal to cut out completely - so it's fairly crappy, but playable and doing an OK job.
My personal preference would be to get a new bass (maybe a Warwick Rockbass Streamer or Yamaha RBX 375) but I want to make sure I do what's best for the band's overall sound. If the band ever gets some gigs then I'll be able to justify shelling out for some more kit, so I think I'd rather spend the full budget I've allocated on one item than spread it across both a cheaper bass and amp which I'll want to replace later.
Not much support for the DI to PA option so far though, which I guess points me towards focusing on the amp.[/quote]
I'd get a luthier to set it up properly, adjust the action on the buzzing strings (if you're not able to do it yourself) and get the bits repaired, and then use the rest of the money towards a new amp.
Just sounds like the action's set too low and/or the truss rod needs adjusting, plus some loose connections in need of soldering/rewiring to me.