Originally Posted by Art M
Replace all those "defective" EI core transformers with Proper Toroidal core transformers then you can quit bad mouthing people.
DF96 "A mains transformer is likely to be slightly asymmetric with respect to stray capacitance from the primary to other nearby stuff"
I was thinking in terms of mitigating the Unbalanced capacitive issue from the primary leads to the core ? Nice symmetry with windings v.s the Toroidal Core mechanicals.
Replace all those "defective" EI core transformers with Proper Toroidal core transformers then you can quit bad mouthing people.
DF96 "A mains transformer is likely to be slightly asymmetric with respect to stray capacitance from the primary to other nearby stuff"
I was thinking in terms of mitigating the Unbalanced capacitive issue from the primary leads to the core ? Nice symmetry with windings v.s the Toroidal Core mechanicals.
Quite the opposite. What I said meant, since the typical audiophile has no formal training in the world of electronic technology... we will at times stumble over something that improves the sound, but are totally inept in our wording when trying to describe it. That's all.
That was not my intent. If I had hi-snobbery I would see no need to be here. I am here to learn.
So... are you saying?
If I came here and said that I reversed the AC phase by turning the plug upside down in the outlet? Instead of saying I reversed the polarity? We could have avoided a very rough intro?
Would that have been the way I should have worded it?
Not exactly, the mains live and neutral you can say have been reversed in polarity as has been said by others, but once they have gone through a transformer they have become galvanically isolated and so the resultant AC is not referenced to earth which is what makes the neutral what it is. So the 12V AC output of your PSU has no polarity of any kind and it makes no difference which way round it is connected.
> Does anyone here remember having toy trains? If AC has no polarity? What made the train able to go in reverse?
I remember the power-pack having a rectifier, outputting DC. So just swap the wires.
Slightly before my time (before Selenium rectifiers), model trains were indeed AC. (Actually a "universal" AC/DC motor, but reversing DC polarity reversed both the armature and the field so they always went forward.) Deluxe locos had a reversing mechanism. Each time the power went to zero, a stepping relay flipped the field connections. Forward, stop, backward, stop, forward. To stop-start the same way you had to blip the power twice.
Nowadays model trains have more CPU power than a moon-rocket and can go any which way.
I don't see how this illuminates the audio question.
I remember the power-pack having a rectifier, outputting DC. So just swap the wires.
Slightly before my time (before Selenium rectifiers), model trains were indeed AC. (Actually a "universal" AC/DC motor, but reversing DC polarity reversed both the armature and the field so they always went forward.) Deluxe locos had a reversing mechanism. Each time the power went to zero, a stepping relay flipped the field connections. Forward, stop, backward, stop, forward. To stop-start the same way you had to blip the power twice.
Nowadays model trains have more CPU power than a moon-rocket and can go any which way.
I don't see how this illuminates the audio question.
Every component I now have has a toroidal transformer. If I flip the plug at the outlet and measure by connecting to a ground on the chassis of the PSU with nothing else connected to it? One plug orientation will read lower than the opposite plug orientation. Every time.
now... If I connect the PSU to power a component that requires and external PS? And, this time take the same kind of measurement at the component? The same phenomena takes place. One plug orientation at the wall outlet will give a higher reading than the opposite orientation at the component's chassis.
This can be measured and verified.... I do not claim in the least to know what is the actual cause. But, we have been taught the lower reading will give the lower noise (distortion) added to the music. And, my ears testify to that being true. When the lower level is found the music becomes audibly smoother and more relaxed.
I may not know what is taking place when the lower plug setting is determined by a VOM... But, my ears have been telling me its a good procedure to follow.
Like I said. You can verify it for yourself. Just make sure what ever component you measure is isolated and not connected to any other component. Remove all interconnects.
I understand how that would be the case with a piece of equipment when using it's internal transformer, I'm at a loss as to how or why it would also be the case with an external transformer. I have no means to verify it myself unfortunately as all my equipment has internal transformers.
Does the component connected to the external PSU have an earthed chassis?
Does the component connected to the external PSU have an earthed chassis?
Thank you. After I asked the question I thought that might be the case.
With speaker hook up? Phase correction is tested when you flip the wires on one speaker to find if they are both in phase. Which proves? Reverse the speaker wires of one speaker and one will be playing in the opposite direction to the other. Again... that is not DC running to the speakers. How can AC be directional? Or, what leaves the amplifier terminals something other than AC?
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The component only has the barrel plug connector powering it.
The PSU should be earthed. No? It has a three pronged IEC socket. Unless the IEC inlet is only utilizing the Hot and Neutral? Hmmm...
In almost all transformers the primary is many layers. The layer closest to the core couples more to it than the outer layers. Even with a remotely mounted transformer there is capacitance from the primary to the secondary. That is why with even a wall wart the is a difference in AC primary feeds to chassis noise.
I don't understand that, if the chassis is isolated, how is an AC feed coupling to it?
That's right, that is phase. AC goes in one direction then the other, like waves on the beach
Yes.... even the original wall wart that came with the unit showed the same preferred outlet orientation when chassis noise was measure. It was counter intuitive. For, I had to turn the wall wart so the power leads were facing upward. Intuitively, most would plug it in with the leads dangling down.
Understood.... when they are going like waves like that? When the speaker wires are out of phase? That shows that the AC positive and negative act in a predetermined direction of action. Its not random.
So? If a plug in an outlet for one component is reversed? That component with the reversed plug? Will be "out of phase" with all the other components its connected with by interconnects. There will be some sort of internal conflict?
So...One might want to check to make sure that the plug orientation of all the components in their system are in phase with one another.
This I do know... When I get all my components "in phase" with the AC outlet with how I have been measuring it? The music is smoother and more enjoyable to listen to. That is why I check for plug orientation... It might prove to be a matter of getting all the components in a system to work in phase with one other. That way everything in ones audio system is flowing in the same way acting as a single unit. Possibly whats taking place?
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Two transformers could still be "out of phase". You are not measuring the phase, only the voltage to ground. It is quite possible that a second PSU could measure or be connected differently.
Re-read post 30. It's not a matter of matching each components 'phase'. You are selecting the lowest leakage/noise arrangement per component. One leg will always have more leakage than the other. The higher leakage leg is ideally connected to neutral. Get each component correctly oriented, you have the lowest leakage and lowest noise. There really is no 'matching phase' between components; this isn't a real-time alignment going on, this is impedance selection.
OK ...
Yet..why does my system sound the smoothest after all the component's voltage to their grounds are set for the lowest reading by the VOM - by means of the plug orientation test?
Can you define what is happening when all units in an audio system are set for their lowest voltage to the chassis of each unit? Can this be defined? I have been doing this in all my systems since the late 80's. Its always produced positive results.
Lets look @ Guitar amplifiers for some information that may clarify this post.
The Guitar amp have a "GROUND REVERSE SWITCH" this give the user a little hum or more hum. The switch injects or sucks out some leakage currents into or out the chassis. The switch is connected to the HOT or the NETURAL of the AC LINE then through a capacitor to the chassis. This work to balance out the leakage currents to reduce any hum currents.
The power transformer primary winding is not balanced and the START or FINISH of the winding has more leakage to the core. As you say reversing the primary wires causes the change in hum/leakage currents to the chassis.
I hope this may help.
The Guitar amp have a "GROUND REVERSE SWITCH" this give the user a little hum or more hum. The switch injects or sucks out some leakage currents into or out the chassis. The switch is connected to the HOT or the NETURAL of the AC LINE then through a capacitor to the chassis. This work to balance out the leakage currents to reduce any hum currents.
The power transformer primary winding is not balanced and the START or FINISH of the winding has more leakage to the core. As you say reversing the primary wires causes the change in hum/leakage currents to the chassis.
I hope this may help.
> flip the wires on one speaker
But if you still have Mono??
That's the thing. AC "phase" has meaning only in-reference-to another AC signal. Left and right. Red and Black (on a US split-"phase" 240V feeder).
You may instead be, as someone says, testing for lowest *leakage*. A very different matter.
But if you still have Mono??
That's the thing. AC "phase" has meaning only in-reference-to another AC signal. Left and right. Red and Black (on a US split-"phase" 240V feeder).
You may instead be, as someone says, testing for lowest *leakage*. A very different matter.
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