I gave an example.
Google for "single point grounding."
Here, I'll do the work for you. Click below:
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I'm not asking you to point to an unrelated article on the web. I'm asking
you to prove that star grounding reduces noise in an electric bass. I mean in real life. Not on paper, and not in Spice or some other model.
Set up a controlled experiment and take measurements. Then post the results. That's how science works. Stop taking someone else's word for it, especially when you are taking that word out of context.
A bass only has a
single ground point at the output jack. Every ground point in the bass is therefore at the same ground potential. You seem to be not understanding that. There are multiple components in the bass which must ground to that point. It doesn't matter how they do it, as there is a ground plane set up in the control cavity. Look at the photo of the Gibson Les Paul I posted.
Here's another example: carbon shielding paint. For shielding, it has a fairly high resistance. Yet, it works and does not generate any weird currents. For the noise hitting that paint, it's the path of least resistance to ground, even if it is a couple of ohms. The common return path the paint is connected serves as an adequate zero-voltage reference level.
Star grounding is for when there are powered circuits that use grounds as part of their circuit. As in a tube amp. You have multiple power supplies going on. You have the filament voltage, and the plate voltage, etc. And they all dump into ground. That's where the different currents on a SHARED ground come into play. To a 300v circuit, the 15v circuit is a lower potential.
A bass has none of that. The pickups are generating a meager current, and any RF noise that hits shields is shunted to ground. It does NOT produce a current on the ground plane.
If it did, then 50 years ago the same people who started star grounding amps would have done the same with guitars. I think Leo Fender and the rest were smart enough to know that. They didn't use star grounding because it's
unnecessary.
I think the problem here is you understand a bit about this, but not enough to see where you are in error.
Since you like to point to the internet, lets take a hop over to Wikipedia. While it sucks of most things, the technical articles are usually quite good.
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A ground loop in a system which connects circuits designed to be at the same potential but which are actually at different potentials can be hazardous, or cause problems with the electrical system, because the electrical potential and soil resistance at different points on the surface of the earth can vary.
Notice it says "connects circuits designed to be at the same potential". There is only
one circuit in the bass.
Further (emphasis added):
If two pieces of audio equipment are plugged into different power outlets, there will often be a difference in their respective ground potentials. If a signal is passed from one to the other via an audio connection with the ground wire intact, this potential difference causes a spurious current through the cables, creating an audible buzz at the AC mains base frequency (50 or 60 Hz) and the harmonics thereof (120 Hz, 240 Hz, and so on), called mains hum.
There's your ground loop. TWO pieces of AC powered gear, plugged into two different power outlets, and then
connected together (i.e. THE LOOP) causes current to flow FROM ONE AC OUTLET TO THE OTHER via the circuit grounds. Humming at the main's frequency. Go back and see I said the same thing earlier in this thread.
If you read further in the Wiki article you will see that ground loops and star topology all have to do with noise from the power supply that powers the circuit. Basses have no such AC power supply in them. Batteries don't generate hum either.
We only have ONE circuit ground on a bass. The wires in the at circuit are just like the
ground plane on a circuit board:
http://en.wikipedia.org/wiki/Ground_plane
In electrical engineering, a ground plane is an electrically conductive surface, usually connected to electrical ground.
A ground plane on a printed circuit board (PCB) is a large area or layer of copper foil connected to the circuit's ground point, usually one terminal of the power supply. It serves as the return path for current from many different components.
In a bass we have many different components connecting to a single ground plane which is generally made up of the shielding, which includes the potentiometer cans (backs).
These are tied together to form the ground plane, which then has a single connection to the circuit's ground, at the output jack. This then connects to the amp's power supply ground via your patch cord. Just as on a circuit board, there is a length of copper (wires) carrying the ground.
)
Which, BTW, makes me think it was the reason why he was a dumb-ass about the whole situation.....
