Well i dont really know mch about Evanescence but I used this tutorial http://www.youtube.com/watch?v=qV7JIHkM2qw

I know its for deep house chords, but with this ive found some slight tweaking can produce a wide variety of success for techno. Even things as simple as a long attack an LFO, some white noise and then you should have some swirly pads

Dont know how useful this is to you but it has been to me