yeah got it working.

It seems SvPascal didn't like a constant instead of a explicit string when declaring external methods.
I had

Code:
const
  bassdll = 'bass.dll';

function BASS_SetConfig(option, value: DWORD): BOOL; stdcall; external bassdll;
...
and had to change it to:
Code:
function BASS_SetConfig(option, value: DWORD): BOOL; stdcall; external 'bass.dll';
...
And I wasn't sure you could use DLL's like this since 'external' wasn't highlighted as a keyword.