In earlier version of NuForce, proper grounding was required as the noise has to be directed to ground. With recent upgrades, this is no longer an issue.
Having electrical ground for safty reason has nothing to do with NuForce design. That's fundamental to electronics devices where the case is grounded. Just imagine. What if the live wire connecting from the IEC socket to the power supply become loose and touches the case? If there is no ground, then you could be electrocuted. This could happen to your hairdryer, PC or any electrical devices. What's the chance of that happening? Extremely small since every unit is tested and the IEC wires connecting the PCB is very tight.
You can talk to our distributor/dealers in Sweden, Denmark or The Netherland where many houses have no ground either. We do have customers who use NuForce amplifier without a ground.