Nuuk said:I was taught that I should have a direct connection between the metal case/chassis and the mains earth and a connection between the main star ground point and the metal case. The second connection being made via a cap and resistor in parallel.
The reason for the first connection is obvious - to carry any high voltages that accidently contact the metal case to ground. But what exactly is the reason for the second connection between case and main star ground?
So what happens when there's no mains earth, as is the case in
Brazil and many other countries?
Carlos
Some time ago I quit using mains earth on my amps.
I mean, what's the use of injecting noise on the precious signal?
Just make the star ground on the case and forget mains earth.
You should have a fuse, mains earth will cause more problems than it solves, specially on buildings, mains earth is not good.
Make it like this, my mini-Krell.
The Cat.5 cable comes from the two RCAs.
This amp is dead silent.
For those who care, this pic was taken with my old, trusty, high-end Canon T90. Good old analog.
I mean, what's the use of injecting noise on the precious signal?
Just make the star ground on the case and forget mains earth.
You should have a fuse, mains earth will cause more problems than it solves, specially on buildings, mains earth is not good.
Make it like this, my mini-Krell.
The Cat.5 cable comes from the two RCAs.
This amp is dead silent.
For those who care, this pic was taken with my old, trusty, high-end Canon T90. Good old analog.
Attachments
carlosfm said:For those who care, this pic was taken with my old, trusty, high-end Canon T90. Good old analog.
How did you process it into digital image? It's nicely sharp.
Regarding mains ground, on my stereo amp I never used it, as it had outboard PS, and never had any problems.
With monoblocks, I decided to attach mains earth to chassis, yet on some amps sent to Europe this created hum problem (seems like earth was missing in ther AC connections) . The chassis had to be connected to signal ground and this fixed the noise problem.
So from now on, I'm also not using earth on the chassis.
Peter Daniel said:
It was scanned directly from the negatives at 6.5 megapixels.
Lens is a Tamron SP 35-80mm f:2.8~3.8 in macro mode.
To fit here, I had to compress the image much more, so you can imagine the original.
Peter Daniel said:
I have mains earth on my living room, where I have my main system.
True, many homes only have mains earth on the kitchen.
Upupa Epops said:What is your " mains earth in living room " ? Well with salt water ? I have " virtual earth " and I have any problems ( maybe because it is on WC, not in kitchen
I call it just earth usually, but we are non-english talking english so... whatever.
You don't have earth on the kitchen?
For the washing machines, the fridge...
No?
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