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My Yamaha 3300 has a 2 pronged outlet and a chasis ground and no where in the manual does it tell the user how to use the ground.

I'd assume there are some extra protection circuits in these type of units to prevent the user from being electrocuted.


Actually I always thought the only reason for this ground was for phono use.
 

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There is no functional use for a ground on any appliance, and its sole purpose is to provide an electical path from the appliance's metal body to your house's grounding system. Thus, if any electrical anomaly occured with the appliance which connected a hot circuit to the appliance's chassis, the breaker in your house would trip and protect from getting zapped by touching the appliance.


Phonos don't have a functional use for ground either. Now, you can have tons of issues with ground noise, etc, but that is a different topic altogether.


No receiver "uses" a ground for anything but grounding its chassis to the house.
 

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You do not need to ground your receiver. As the last poster pointed out it serves no purpose.
 

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Quote:
Originally posted by dm
Could not grounding the chassis help in RFI/EMI shielding?
RF interference would have little impact on a home theater receiver. Only in rare circustances such as living next to an airport radar or TV station would RFI be of concern and grounding the chassis probably wouldn't stop it anyway. The only source of EMI would be the 60 Hz power line and that penetrates the chassis anyway in the form of a power cord.

Unnecessary grounding on the other hand can introduce hum problems through ground loops.
 

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Quote:
Originally posted by NightHawk
RF interference would have little impact on a home theater receiver. Only in rare circustances such as living next to an airport radar or TV station would RFI be of concern and grounding the chassis probably wouldn't stop it anyway. The only source of EMI would be the 60 Hz power line and that penetrates the chassis anyway in the form of a power cord.

Unnecessary grounding on the other hand can introduce hum problems through ground loops.
I have a HTPC in my stack which while not a TV station, does generate a fair amount of RFI. It can be seen as patterns on certain channels tuned in on my VCR. Iron beads and chokes help on the various signal lines coming and going from the equipment.
 

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Almost all two pronged appliances use the grounding plug method where one pin is larger than the other so it can only be plugged in one way. This is to ensure that the body of the unit is not closer to the hot side than to the earth ground side. Other than that, all components are ground referenced to each other through the use of shielded cables. Equipment is much less susceptible to ground noise than it used to be as power is filtered and reformed by almost all the components in your stereo individually. Phono players would still have to be grounded to the amp or preamp they are connected to, but it is just so they have the same ground reference to reduce hum and rumble, not to ground the turntable itself. The reason you need to ground a turntable is because the needle is not electrically connected to the turntable. The only thing that is powered in the turntable is the motor to turn the record, not any of the audio path. In all your other stereo components (CD, DVD,etc.) the audio connections have a ground reference on the shield portion of the connector, phono uses a differential, or balanced signal, with no ground, so the ground pin is to provide audio reference ground between the devices.
 

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Quote:
My Yamaha 3300 has a 2 pronged outlet and a chasis ground and no where in the manual does it tell the user how to use the ground.
I'm not familiar with that receiver but is the "chassis ground" right next to the connector for the AM antenna? If so, it's meant to be used to provide a ground plane connection for a single-ended AM antenna. Nothing to do with the AC power. Check your manual in the section about hooking up the antennas.
 

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Perhaps a better question might be why do most separate power amplifiers have 3 prong power cords with ground pin and most receivers (which have 2-7 amplifier channels in them) only have two prong power cords?
 

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Quote:
Originally posted by EMT
Perhaps a better question might be why do most separate power amplifiers have 3 prong power cords with ground pin and most receivers (which have 2-7 amplifier channels in them) only have two prong power cords?
i've often wondered this aswell...:confused:
 
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