B22/Active Ground Query

[Steve Eddy]

Quote:

Originally Posted by amb /img/forum/go_quote.gif I'll just cite the M³ (and PPA, Pimeta, etc) as an example of why that current does NOT go to ground because it's easier to illustrate.

No need to complicate and confuse the issue with some apples and oranges example, just tell me where the current goes after it reaches the ground channel's negative rail in the situation we've been talking about.

Quote:

If you're referring to a private message I had with someone, it's only because two doesn't divide into an odd number of amplifier boards very well, and it's too much to ask one σ22 PSU board to power five β22 channels.

But there are only five channels because one of them is the ground channel.

And since the active ground channel doesn't divert current away from ground, and since it can't provide or constant supply current draw, then what purpose would the ground channel be serving?

k

 

[Beefy]

Quote:

Originally Posted by Koyaan I. Sqatsi /img/forum/go_quote.gif No need to complicate and confuse the issue with some apples and oranges example, just tell me where the current goes after it reaches the ground channel's negative rail in the situation we've been talking about.

You really like arguing, just for the sake of arguing, don't you?

 

[amb]

It's not an apples and oranges comparison. The amplifier doesn't "know" whether the ground is "real" or "virtual", and the current flow is the same in all cases. Essentially, that current ends up back at the power transformer which supplies the raw AC.

Look, it's obvious that you're not convinced about the benefits of a ground channel. If that is so, do without one. Be happy.

 

[Ferrari]

Quote:

Originally Posted by Koyaan I. Sqatsi /img/forum/go_quote.gif ... just using a passive ground. k

Why not just take all the liberty, do it and be happy???

 

[Steve Eddy]

Quote:

Originally Posted by Beefy /img/forum/go_quote.gif You really like arguing, just for the sake of arguing, don't you?

No, I don't. And this isn't an argument for the sake of arguing, it's an argument for the sake of getting at the truth.

amb claimed that the ground channel diverted the current from ground.

I believe this claim is absolutely incorrect. So I'm asking amb to substantiate it.

k

 

[digger945]

If you'll hold on a second, I think I may be able to compose a little something that will perhaps help you to better understand. I hope.

 

[cfcubed]

nevermind.

 

[Steve Eddy]

Quote:

Originally Posted by amb /img/forum/go_quote.gif It's not an apples and oranges comparison. The amplifier doesn't "know" whether the ground is "real" or "virtual", and the current flow is the same in all cases. Essentially, that current ends up back at the power transformer which supplies the raw AC.

You claimed, in the context of the B22, that the active ground channel diverted the load current from ground. In other words, the load current doesn't go to ground. Instead, it goes someplace else other than ground, thereby preventing ground from being contaminated by the load current.

The someplace else it goes, instead of to ground, you said was the ground amplifier's negative rail.

Well, it can't just go there and stop. Nor can it spill out onto the floor or evaporate into the air.

It has to continue on to someplace else. And as I said in a previous post, that someplace else is ground, which is contrary to your claim that it doesn't.

Now, I'm fully prepared to be wrong here. So all I'm asking is the simple question, where, in the context of the B22, does the current go from the negative rail if it doesn't go to ground?

And if I'm not wrong here, then it doesn't serve people to be told that the active ground diverts the current away from ground when that's simply not the case. Surely you would agree to that, wouldn't you?

k

 

[Steve Eddy]

Quote:

Originally Posted by digger945 /img/forum/go_quote.gif If you'll hold on a second, I think I may be able to compose a little something that will perhaps help you to better understand. I hope.

And I'll do the same.

k

 

[digger945]

If you can imagine the left positive amp board sending a positive or negative going voltage down the wire to the headphone transducer, through the transducer and then returning along the other wire, the ground wire if you will, back to the active ground amp's output terminal where it is looking for a place to go. It then travels along the active ground amp's feedback circuit up to the input of that same active ground amp, where it is compared with signal ground, which is tied to power supply ground through a 1k resistor, it measures the difference of the two and sends that signal through the various stages in the active amp board to the output devices, which then try to hold the output of that same active ground amp as close to steady as they can, by using, if necessary, whatever they need (as dictated from the input) from the positive or negative rails, and making the output voltage a steady zero.

If the ground wire from the headphone needs a place to sink current, the amp does that though the positive rail, if the ground wire of the headphone needs a place to source current, it lets it have it through the negative rail. All this without using the ground that you are accustomed to thinking of, signal ground or power supply ground.

Now I'm sure if I made any mistakes that someone will be bold enough to point them out to me

Just trying to help, and maybe learn a thing or two myself.

 

[digger945]

Quote:

Originally Posted by Koyaan I. Sqatsi /img/forum/go_quote.gif And I'll do the same. k

Well I'm taking a break to go to the post office and pick up my new Stax. Don't even ask me how they are grounded

 

[amb]

Quote:

Originally Posted by Koyaan I. Sqatsi /img/forum/go_quote.gif So all I'm asking is the simple question, where, in the context of the B22, does the current go from the negative rail if it doesn't go to ground?

I had already answered that, to the power transformer. But in the case of a 3-channel amp, it's irrelevant, because all that current summed to zero on the rails and got cancelled.

 

[johnwmclean]

Has anyone seen the movie 'Envy' with Jack Black and Billy Crystal? Remember the famous 'Vapooriser'....

Where does the poop go? It's gotta go somewhere, but where?

 

[Steve Eddy]

Quote:

Originally Posted by amb /img/forum/go_quote.gif I had already answered that, to the power transformer.

No it doesn't. It goes to ground.

First, the transformer's not even in the circuit most of the time. The load current's not going to sit around playing solitaire waiting for the next refresh cycle.

Second, the power transformer's dumping current into the reservoir caps, while the amps draw current out of them.

k

 

[Steve Eddy]

Quote:

Originally Posted by johnwmclean /img/forum/go_quote.gif Has anyone seen the movie 'Envy' with Jack Black and Billy Crystal? Remember the famous 'Vapooriser'.... Where does the poop go? It's gotta go somewhere, but where?

Yup! Saw it.

k