Plus 1 for echo audiofire 12- when running by itself-never a click or pop-running 8 lines out summed analog and back in.
Presently running Hedd clocking audiofire 12, running 8 out DAW via audiofire 12 summed analog back in via Hedd occasional clicks - but still very operational. Combining Hedd with Lynx PC card with audiofire 12 (firewire) and being operational is testament to Echo
GJ
Newcastle/OZ