I use the Mainline with the GS-3000x and it makes a fantastic combo.. Keep in mind that the Mainline is very neutral but detailed.. S3X is also very good.. I used it a lot with the Grado Hemp... There might still be a S3X 3.0 kit on sale ... Just ask Doc/Eileen..
But if you want more slam and oomph then maybe C2A or Crack along with a good high impedance headphone will be the way to go..
