[daninjt]

When the guys installed my 3B SST and BP20 they seemed to pay particlur attention to which way the plug was plugged into the power point as if the polarity were an issue.  

For curiosity sake, does it matter which way amps, or components in general, are are plugged in?   In Indonesia they use 2 prong plugs which can be plugged in right side up or upside down.

Cheers,

Dany

[James Tanner]

I will find out for you.

james

[Mike Pickett]

Hi Dany;

From a performance standpoint, it shouldn't matter which way the plug is inserted, as long as it is grounded properly.  The Indonesian plugs we have here seem to ground in both orientations, and the amps will work either way.

However, from a legal/safety standpoint, it does matter, since the fuse, breaker, and power switching are intended to be on the Hot side of the circuit.  If the plug is reversed, this will place the safety components on the Neutral side, which is still effective in case of an overload, but won't protect the amp in the case of an internal short to ground.

This is probably why the installers paid attention to polarity in this case.

Mike

[Phoenix]

First: Excuse me if I don't get the right "technical" words in English...

Here in Germany, the plugs of the Bryston amplifiers are marked by Sun Audio.
The marked pin should be connected to the live wire.

And, if possible, the other equipment should be connected the same way.
However, it is difficult to do so because companies don't mark them often.

As I understood it has something to do with a difference in potential voltage between the units in your setup.
The voltage can be measured and with the plug in the right position this potential voltage can be minimized. CD, amplifier, etc. each have a different potential voltage.

Because the voltage wants to even out in your setup, there is alway a little current flow between your units over the ground of your signal cable.
This is said to deteriorate sound quality.
So the aim is to lower the voltage difference between your units and in your whole system.

So it COULD be important how the plug is connected to the socket.

Don't know if this is correct, but I guess James will find an answer!

[nicolasb]

Phoenix, what you're talking about there is what's usually called a "ground loop", and it's the result of differences between the "ground" or "earth" potential experienced by the different components. It manifests itself as a hum on the output. (One of the advantages of balanced XLR connections compared to unbalanced phono connections is that they don't experience this effect).

But I can't see any way that reversing the Live and Neutral wires in the mains plug would have any influence on the Earth potential.

[Phoenix]

@nicolasb

THX!
A groud loop is called "Brummschleife" here in Germany. Very much the same.

But I can remember that even German Hifi-Magazines (like Stereo, Audio) recommended a few years ago, to change the polarity of the equipment and try to hear a difference. The even suggested to measure it - but I don't know how. I will search for the articles.


EDIT:

....there are many articles.....

for e.g. this one: http://www.vandenhul.com/other/c-care.htm#polarity

[daninjt]

..for the replies, especially the Bryston guys.

[daninjt]

Another question if I may.

What is the polarity switch for on the BP20?

Cheers.

[Yogus]

Another question if I may.

What is the polarity switch for on the BP20?

Cheers.

It reverses "absolute phase".

Don't ask me what effect it has on the sound, because I can't tell the difference whether its orange or green.

It might be useful if you have source components into a balanced input that reverses absolute phase (e.g. Chord DAC64).