Wut

No reason you wouod need an amp if you have a receivers to plug it into unless the receiver causes static or something.

I’ve been considering a pair of these saw them for like $150 CAD the other day seems like a good price.

Are you deaf?

If there is corrosion you need to get rid of it as soon as possible, or it will ruin them. But with the way most iems are designed dont know how you would do that without damaging them.