[Steve Eddy]

after 1 foot of dirt, pure clay. its a great ground.

That's nice. What purpose does it serve though with regard to your audio gear?

se

 

[Steve Eddy]

3 pin refers to the socket build into the amplifier? or are we talkin abt the 3 pronged male end of the power cord?

It's all part and parcel of the same thing.



se

 

[money4me247]

It's all part and parcel of the same thing.

so you are saying that amplifiers using a 3-pin socket to a 3 prong power cord is a poor design choice in your opinion? could you link me to amplifier designs using something different. I do think all the amplifiers I've used have a 3-pin socket.

 

[Priidik]

That's nice. What purpose does it serve though with regard to your audio gear?

se

I have done the same thing.
While i can't say for sure if it makes anything sound better, but at least my precious stuff is away from common household garbage. My computer case has 112V 50Hz (of 230), luckily only 1mA on it for some reason, so i get a reminder if i touch my dac and Apple keyboard at the same time

 

[Steve Eddy]

so you are saying that amplifiers using a 3-pin socket to a 3 prong power cord is a poor design choice in your opinion? could you link me to amplifier designs using something different. I do think all the amplifiers I've used have a 3-pin socket.

It's not inherently a poor design choice. In some instances it's required for safety. In fact, that is its only purpose. In the U.S. it is tied to neutral back at the service panel. It's to provide a return path for current should the power supply fail in such a way that hot comes into contact with metal chassis parts that could present a risk of shock to the user. By code, the third pin must be tied to the metal chassis by the most direct means.

It's only required for what are called Class I chassis. In a Class I chassis, a single insulation failure can result in hot coming into contact with metal chassis parts. A Class II chassis, also called "double insulated," requires at least two insulation failures before this can happen. Most consumer audio gear meets Class II specs and typically only uses a two prong polarized plug.

In so-called "high end" audio, the three prong IEC came to be thought of as a sign of "quality," rather than an inability to design a Class II chassis or even understanding what a Class II chassis meant. So consumers had this huge ground loop generator foisted on them when in many cases it wouldn't have been necessary.

Bottom line, neither this third pin, nor a rod stuck in the dirt has any relevance at all to the proper grounding of an audio system. Audio gear all uses internal reference grounds.

se

 

[Steve Eddy]

I have done the same thing.
While i can't say for sure if it makes anything sound better, but at least my precious stuff is away from common household garbage. My computer case has 112V 50Hz (of 230), luckily only 1mA on it for some reason, so i get a reminder if i touch my dac and Apple keyboard at the same time

Hehehe. Where's that smoking singed hair smiley?

se

 

[kevin gilmore]

That's nice. What purpose does it serve though with regard to your audio gear?

se

very low impedance ground rod.
 
what you have not said about the 2 wire double insulated plugs on some equipment
is that the plug is polarized and the neutral wire is connected to chassis ground thru
a 100k - 220k resistor with a small cap, typically .01uf to ground. And if you make
the mistake of using cheater adapters and accidentally flip the adapter, you have
lots of ground noise.
 
For equipment like this, it adds ground noise directly to the chassis, and it eventually
gets thru to the entire audio system.
 
And like you said, this is all about safety anyway, not making a totally quiet audio
system.
 
So with a transformer isolated balanced power 110vac system, you have to make
things safe again. Not that hard really.

 

[Steve Eddy]

very low impedance ground rod

Low impedance to where? The earth isn't a one-way current sink.

what you have not said about the 2 wire double insulated plugs on some equipment
is that the plug is polarized and the neutral wire is connected to chassis ground thru
a 100k - 220k resistor with a small cap, typically .01uf to ground. And if you make
the mistake of using cheater adapters and accidentally flip the adapter, you have
lots of ground noise.

For equipment like this, it adds ground noise directly to the chassis, and it eventually
gets thru to the entire audio system.

I've not seen that in any reasonably modern gear. I've seen it (as well as several other schemes) used in three pin gear in an attempt to isolate the internal reference ground from the chassis which is tied to safety ground.

And like you said, this is all about safety anyway, not making a totally quiet audio
system.

So with a transformer isolated balanced power 110vac system, you have to make
things safe again. Not that hard really.

The ground rod is only for safety from lightning strike, and that's already taken care of in your regular AC mains. In your balanced power arrangement, the third pin need only go to the center tap of your isolation transformer, not to a literal earth ground. That can only cause noise problems.

I remember an epic argument I had with the late Dan Banquer. He insisted that a literal earth ground would make for a quieter audio system. I said just the opposite, it could only make things worse.

He basically called me an idiot, and said that I should talk to someone who REALLY knew about these issues, like Henry Ott, who literally wrote the book on noise.

So I got in touch with Henry and he agreed with me, and said a literal earth ground would only serve to make things worse.

When I told Dan, he threw Henry under the bus and that I should talk to someone who REALLY REALLY knew about this stuff, like Ralph Morrison, who also wrote a book on noise.

So I got in touch with Ralph. And he too agreed with me.

Dan threw Ralph under the bus as well and mentioned some third guy whose name escapes me now, think his first name was Mike. And he too was in agreement with me along with Henry and Ralph.

However in spite of agreement with me from three well recognized authorities on grounding, shielding and noise, Dan went to his grave still believing that a literal earth ground would make for a quieter audio system.

So yeah, you can safely ditch your ground rod. The Lightning safety issue is already taken care of by the ground rod that your normal AC mains is connected to. You only need the safety ground to return to the center tap on your balanced isolation transformer.



se