techno doesnt sound all that bad actually from other video's I've seen. Playing guitar through it really sucks cause it sounds like piss to begin with, but then the strings make all these harmonics that make the hard drive go nuts. If you hit certain notes it goes all crazy and buzzes like its going to explode. After playing for like 10 minutes at pretty high volume I started smelling funny stuff like the coil was overheating. It was physically hot... I could definitely blow it out with my receiver.
I found the volume was much greater when the coil was sitting directly over one of the magnet poles. I had the platters completely off, but the hard drive had a little better sound with them installed. I think if you have the arm touching the platters it really takes away from the sound. It probably had more to do with more mass in the drive transferring sound into the desk.