Hey Paul, you may want to invest in a clipboard (or small white board) so it will be easier when you have to write or illustrate something on paper.

The poorly named "ground" is the line in a system designated as "zero" for voltage measurements. It must be able to source (provide) or sink (take in) as much current as necessary for the operation of the circuit without changing voltage, i.e., zero resistance (impedance) although in reality the minimal impedance of a properly sized conductor. This "zero" reference is generally a common, unswitched rail, i.e., wire, trace, etc., across the circuit. From this "zero" reference, voltages measured may be positive or negative on the load side of the circuit as needed by the design. Better terms are "common" or "return". The latter because current must have a return path to the power source and convention often designates this as the "zero" reference. The "ground" prong on the plug is the "safety ground" and is strictly a low resistance path from any conductive part of the equipment case back to the breaker should a fault cause the "hot" conductor to come into contact and thus energize the parts someone might touch during common use. This low resistance path produces a high current that trips the breaker "clearing the fault", i.e., turning off the hot conductor. The actual "ground" or earth is the "system ground" which is the ground rod bonded to the neutral. The ground rod provides a low resistance path to the earth for induced high voltage spikes in the wiring from nearby lightening, as well as inductive load switching and switching arcing faults rather than them arcing through insulation shorting motors or igniting something flammable, or, these days, blowing up electronic circuits.

@Chris-ql1pd

3 жыл бұрын

Much better explanation! Well done! Well worth and makes up for the 5 minutes I spent watching this guy scribble on scrap paper..

@Jorge-Fernandez-Lopez

2 жыл бұрын

Great explanation JK Brown, thank you. However, the safety ground is not bonded to the neutral everywhere. Sometimes ground cable (yellow/green in my home) goes directly to earth via the main panel without any connection with neutral. In the main panel, all circuits (phase [hot] and neutral) have also circuits breakers for excessive current, but there's a main differential breaker that detects very quickly any difference of current (30 mA) between neutral and phase. This differential breaker cuts electricity off, before circuits breakers do without need of high currents. Spikes goes through another device in the main panel: surge protectors.

I love it. I had been pondering this all weekend after reading about an amp that had no need for safety ground because it used a double isolated power source. "HOW DOES THE SIGNAL GET GROUNDED THEN?" was my howl into the wind. I was sort of getting nowhere although I did get as far as comparing this sort of circuit with using jump leads on a car. I always wondered why one of the clamps is clipped to the chassis. Some places said it was to 'ground' it. I couldn't understand how it did that with those big fat rubber tyres holding the car off the ground in a beautifully insulated way! But I also thought I was barking up the wrong tree since cars are using batteries with DC power rather than an amp using AC power. I was afraid I might be muddling myself up in a potentially dangerous way. But your video completes the circle that I was so painfully slowly trying to close. From now I think I will call signal ground 'common' instead so I am no longer confused. So great to see it so clearly explained. Your mention of 'ground' in space sealed the deal!

Thank you for answering my questions and saying my name correctly :)

Muy bien explicado!! Un saludo desde España

Great explanation. Crystal clear. Reminds me of 'reference planes' to measure motion in physics.

The power strip in the background has a flickering neon light on its power switch. Might be causing some problems depending on the circuit. Since it's flickering though, might be time to replace the power strip?

@tvtech2582

6 жыл бұрын

This is typical with neon lamps,the electrodes just excite the gas.They cause absolutley no rf interference.

The answer of course correct but what would be nice to know, is the role (if any) of the 3rd wire/"ground" in audio devices (besides safety measure - grounding housing of an electric device)

Well explained !

Something I noticed is that I see many people in US forums complaining that Rega turntables hum a lot over some other TTs but here in the Philippines where we have just two prong plugs with no ground, the Regas actually are quieter than TTs with a ground wire. Any idea why? Is the rega designed for eu style plugs or in my case Philippine plugs more than 3 prong US plugs? I wonder how I can get around totally removing hum from a VPI turntable with the standard RCA plus ground wire configuration. My friend has already dug a hole at the backyard to connect the ground wire to a ground post to eliminate this hum. Such a hassle. :D

@oysteinsoreide4323

5 жыл бұрын

For audio gear it's often best to not have ground. Because some electrical equipment makes noise on the ground circuit and transfer it to audio gear.

This is a great video Paul and one that takes me back to school..I do want to ask you though a 2 part question. So you've listened to valve and solid state I'm assuming so for you which floats your boat or is it a case that either works depending on system..Secondly in the valve (tube) world we have many different kinds of amps. Now if we compare valve to solid state, there has never been to my knowledge in the past or today, a OTL solid state amp..So why has a OTL solid state amp never been built..Or maybe it has I have no idea. Many thanks Garth

Ground is the common return path for total circuit current?

What if I connect the signal GND to actual ground or the chassis to actual ground?

Great explanation, I like Paul's circuit explanations because that is his specialty. The speaker explanations are interesting but I don't think that's his core competency.

UK, Ireland and other countries have 3 pin electric plugs, so is all their equipment grounded?

We can also have a pseudo ground to split the 9V into +4.5V and -4.5V.

You can still buy a ground earth rod to bury in your ground. I've seen old ones in old homes, the rods were about 18 inches long iirc.

So, basically ground = 0v?, or even the negative rail?

@michaelmcdermott4385

3 жыл бұрын

I believe is is basically the point of lowest current overall, but like he said, it depends on how you define it... You could say that the negative rail is ground, but most often, people would reference GND as being the point of lowest overall voltage, usually at 0V.

How can we actually increase the ground in an amplifier

@DasAntiNaziBroetchen

4 жыл бұрын

What?

There is Ground Type A. Connected to the earth. Then there is a ground, type B? Like with a battery. Is B an ersatz ground? For you could not use B ground for a lightning rod for example.

Wat about AC?

Then why do your products have a line level ground at all?

I always learned to refer to it as common in school and ground was referred to as earth .

Haha chingadera reminded me of my old teacher.

@PastafarianLemur

3 жыл бұрын

Yeah the "chingadera" part caught my attention too. XD

ground= negative rail/common negative rail. job done ::-) t.u.#69 no less !

@JohnAudioTech

6 жыл бұрын

Back in the germanium transistor days, there were a lot of positive ground devices. Dual supply devices such as power amplifiers will have the a negative rail, ground and positive rail. So ground is not always the negative rail.

@gizmothewytchdoktor1049

6 жыл бұрын

it's been a long time since positive earth was a common thing ;-) guess that term sort of dates me a bit.

chingadera lol!

@dipsyfriday

6 жыл бұрын

yeah - if he knew what that word meant he might not have said it!

>these little chingaderas LOL

This is a great video Paul and one that takes me back to school..I do want to ask you though a 2 part question. So you've listened to valve and solid state I'm assuming so for you which floats your boat or is it a case that either works depending on system..Secondly in the valve (tube) world we have many different kinds of amps. Now if we compare valve to solid state, there has never been to my knowledge in the past or today, a OTL solid state amp..So why has a OTL solid state amp never been built..Or maybe it has I have no idea. Many thanks Garth (Oh I'm fro Northern Ireland)

@DasAntiNaziBroetchen

4 жыл бұрын

Quick google search tells me they exist: www.transcendentsound.com/son-of-beast.html