Ungrounding an Amp--Any Danger?

The idea in "star-grounding" is to leave the component with the highest voltage potential -- the amp -- grounded, and to unground everything (everything) connected to it.
BUT, if you want to determine if the hum is intrinsic to the amp, just disconnect all inputs, so that the integrated has ONLY the speakers still connected. If there's hum through the speakers when you turn the unit on, then you'll know that the problem is not due to a ground loop. If there's no hum, then you may want to try star-grounding.

Ground protects you from being shocked in the event of an internal failure. Cheater plugs are routinely used to locate/cure ground loop issues. Violates electrical safety codes, hence the warning.

Defeating a three prong power cable with a "ground lifter" etc., is not only dangerous, it defeats the UL listing (Underwriter Labs is an independant body which tests electrical devices for safety under extreme conditions), and will invalidate ANY and ALL insurance claims that occur as a result of that equipment. The ground is there for a reason (aside from causing ground loops): in the event of electrical fault within the equipment (caused by internal or external forces), the ground acts as a safety to safely shunt excess current away from the chassis and you. Solve your hum problem by finding out what is causing the hum in the first place.

Joe, I'm not sure you're right about grounding thru the amp. Yes it will provide a single ground path, but I understood that "star grounding" is when each component (or each device on a circuit board or chassis) has it's OWN shortest path to the ground point -- thus making the preamp the preferable compoinent to ground, and not the amp.

One thing a lot of people forget to do when using the preamp as the center of the "star", is to make sure ALL directional arrows (if present on the interconnects,) point to the preamp. This insures that all shielding inside the ICs will be connected to ground at the preamp. This isn't 100% true 100% of the time, but MOST cable manufacturers point the arrowheads to the end of the interconnect where they've connected the shield (the other end is not connected). The reason for all the BS about pointing the arrows in the "direction of signal flow" is so the manufacturers can get you to do the right thing without going into an explanation that might be over the head of most consumers.

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Thanks for the warnings. I am recalling a story I heard some years ago about one of the former members of the Yard Birds. He electrocuted himself while tuning his electric guitar. I assume his guitar amp wasn't properly grounded.

The hum is definately in my amp since it remains when I disconnect my CDP. Since it's an integrated, there are not separate power plugs for the preamp and amp. Besides, the preamp is passive.

I have seen several products designed to block RFI and EMI, like the Stillpoints ERS cloth ($20 at Music Direct). Would these products be of any help? If not, the hum is minor enough that I can live with it.