Bass amp causes any amp to make funny crakling noises...why?

What kind of bass, and what kind of amp?

Have you tried more than one cable? That’s a pretty common cause of this type of problem. The output jack on the bass could also be the problem. Make sure that it’s a solid connection. Also make sure the pots are clean.

I kind of need to know the model of bass to help you here, though. It is hard to acess the output on some basses (i.e. les paul), and I don’t want you cutting up your instrument before we get anymore info…

Oh. Right. I should read the description.

Check your output jack and make sure there isn’t any crap in there.

Is it an active or passive electronic bass?

active or passive?
and i checked the input thing on the bass with a q-tip…its fine…
could it do with pickups?

Check your pickup connections, on the inside of the bass.

Active/Passive

It’s basically how your guitar is powered.

@roysters5 To put it more simply: as a general rule, if your bass requires a battery, then it’s active. If it doesn’t require a battery, then it’s passive.

@aidje: Yeah. That’s it.

most likely its the connections have you tried different cables?
also it may be the solder on the inside of the bass have you checked that?
spray WD40 lubricant on the jack before you plug into the bass

it could also be background noise from other electrical equipment