Equaliser resets between tracks.

[tripletremelo]

So I get some distortion on certain songs when the EQ is on, but lowering the pre-amp and playing with the other sliders can get rid of it.

The problem is every time I change tracks it goes back to where it was before. When I look at the equaliser is still looks the same but I can tell it's different.

For example the pre-amp is at -3.3, it sounds good, then it goes to the next track, distortion. I open the equaliser and slide the pre-amp UP, yet it gets quieter. Which means the pre-amp was at even higher even though it says it is still at -3.3

I tried saving a setting, and after it skips to the next track I re-select that preset it's already on, and again it gets quieter.

[hiccup]

You could check if the files have ReplayGain values active, or perhaps have 'volume adjustment' set for them.

[tripletremelo]

Yeah all those settings are switched off.

[phred]

But have you checked the files to see if, as hiccup suggests, replay gain values exist.
You need to use the Tag Inspector to do this. You'll find the Tag Inspector in the Tag Edit window above the tabs.