I'm looking at a Carvin LB76 on craigslist. Just went to the guy's house and tried it out; the bass itself is very nice, but the action is way too high for me. The bridge is about as low as it can get, so I'm thinking that it's all due to tension / truss rod (the neck did seem kinda concave). My question is, since there's no way to return it, how likely is it that I'll be able to get the action low? I don't mind some fret buzzing as long as it doesn't come through the amp. I have no problem taking it to get professionally set-up. I'm comparing it to the action of a new Ibanez SR506. Thanks!