My power Outlets do not have a ground..

[zei]

Will this be a problem for me when putting together the LM4780 kit from audiosector?
It is finnished but i have not started it yet..

/z

[Mick_F]

No, that should not be a problem. Probably you have a little bit more noise, but you will not destroy the amp.

You can make a separate ground connection to a heater radiator or water pipe.

Mick

[zei]

I actualy assembled the amp yesterday night and.. no noise at all.
The sound is incredible

Thanx
Z

[peranders]

As I say about LM3886 and LM4780 (= 2 pcs. of LM3886 chips inside), they are surprisingly good.

To answer your question: As you may have noticed almost no hifi equipment requires protective ground.

[SY]

Without a safety ground, it is mandatory that the chassis and anything the user can touch be double-insulated.

[Christer]

Originally posted by Mick_F

You can make a separate ground connection to a heater radiator or water pipe.

No he can't. That is strictly forbidden and unsafe.


Unfortunately, most swedish homes don't have outlets with ground except in kitchens and bathrooms, so this is a common problem for us. There isn't much to do about it, unless one takes the cost of getting the home rewired. As SY said, equipment should be double insulated to adhere to safety regulations when there is no ground.

[metal]

Hello

Ground connection can be easily made man...here is a suggestion.

If your home's got a small garden, then bring a copper rod of about 80cm long, and 2cm thick...

Don't dig any thingy in the soil, just start inserting the rod in the soil using a big hammer, until there is 10cm left or the rod ubove the soil, try to find an area where the soil is not completely wet, and not completely dry. Then connect a fairly thick wire "Say 2 mil" and bring it to your new outlet for amplifiers !!

When you finish, call the electricity company to do their tests, the impedance should not be more than few milliohms. I think its a tedious work, but worth the trial, I did that my self, and I hade to use two rods, any way, ground connection is not only intended for protection, also all 100Hz hum disappeared from my speakers when I connected the chassis to the ground connection I made, believe it or not, this is an inherent problem, and can only be removed by connecting the ground of the amplifier with the ground from the outlet....



Good luck

Warning
Don't ever try to create a ground connection using water pipes in your home, if a leakage from the amplifier transformers occurs, then all water pipes might carry the hot line potential which is very dangarous and lethal, hence, if you wanna wash your hands, while your feet arenot isolated from the bathroom floor, for example, you will get fried, and get holes in your legs !!

Look at this photo which is for a man who was shocked by a broken lamp wires

[Mick_F]

I assume that there are no houses in which the water-pipe system is not properly grounded. Then, if the case is connected to a potential, your fuse should blow.

Mick

[fcel]

1) 80 cm looks too shallow to me - to be able to achieve few milliohms.
2) You may have cadweld equipment at home to make the connection from the ground wire to the ground rod but I believe most of people do not have it.

So, it's not that simple.

[pinkmouse]

Post #8
I assume that there are no houses in which the water-pipe system is not properly grounded

You might be suprised. All it takes is for a bit of copper to be replaced with the new plastic pipework, and there is no continuity. In the UK, building regs state that every sink, bath or other appliance has to have a separate earth bond wire, run back to the main earth conection.