Removing the ground on PC?

I'm sure you already know this, but the presence of a ground connection indicates no double-insulation, so removing the ground does expose you to the small but real risk of electric shock if the casing ever became live.

Is the improvement in sound worth such a risk?

I'm very surprised and bothered by the sheer number of people who disconnect/remove the earth from their PC to solve a hum or noise issue. That earth connection is there for a very good reason - to stop people dying from mains voltage shocks in the event of a component failure.

There are times when the quickest and cheapest solution to a problem is not the smartest, and this is one of them.

Quite frankly, in this day and age of modern high end gear, I'd take an amp/source component straight back to the dealer for a refund if it 'hummed', or have my house wiring checked out, not start stuffing around with mains voltages and risk a live chassis.

Newbee, it's true that your source will be grounded via the IC (if it doesn't have it's own) to the amp's ground pin, provided your amp & source use the chassis as a common ground (usually the case), but that's under normal operating conditions.

The big problem is that IC cables are not designed to take mains voltages, and it will be the outer conductor in the IC that cops it - often a very fine copper braid designed for just a few volts. Using Australia's mains as my example, I doubt a typical IC will stand up to 240VAC at 10amps for long, and in a split second you may be back to having a CD player with a live outer casing. At the very least it would likely burn out the IC and start a fire.

As I said earlier, I'd be looking for the source or cause of the hum, not removing a safety aspect. If a component has a 3-pin PC, then the unit is not double insulated and by law has to be properly earthed. If a fire started due to the removal of an earth pin, I know what your insurance company would say.....