A good 'record' shop?
 

"Bob Latham" wrote in message
...
In article ,
David Looser wrote:
"FedupLurker" wrote

You're wrong again, that's not what it's about. The detachable
figure-of-eight mains connection allowed for system matching. (All
mainstream hardware OEM's from Arcam, through Philips/Marantz to
Sony/ Technics adopted it through 80's into early 90's) Because you
didn't know about it (or the numbskulls of the clique) doesn't mean
that hardware with capability to invert polarity via such a mains
interface and resulted in dramatic sonic differences depending on
polarity to PSU, well...

Do you even know what the word "polarity" means? Because the
badly-written and even more badly thought-out rant above suggests
otherwise.

I would have thought that polarity was a dc consideration not AC. I do
have some electronics knowledge and qualifications and I can't think of
any explanation why reversing a mains lead feeding the primary of a mains
transformer would make the slightest difference. However, it certainly did
appear to at the time.


As Jim pointed out it *can* make a difference because mains is unbalanced.
So if the layout is poor you can get hash from the mains supply coupled into
the signal circuitry and the level of this may depend on which way round the
mains is connected, though in a well-designed unit the effect will be
negligible.

But FUL's phase "hardware with capability to invert polarity via such a
mains interface" is just so much meaningless gobbledegook.

David.

A good 'record' shop?
 

In article , Bob Latham
wrote:


I would have thought that polarity was a dc consideration not AC. I do
have some electronics knowledge and qualifications and I can't think of
any explanation why reversing a mains lead feeding the primary of a
mains transformer would make the slightest difference.

Trivial example of how it could. Consider a PSU designed so that the
'Neutral' wire to the primary goes much closer to sensitive circuitry than
the 'Live' wire.

Since the ac voltage on Neutral is (or should be!) far smaller than on
Live, when connected the 'correct way around' the level of hash injected is
then lower than when the 'wrong way around'.

Similar arguments can apply when the 'wires' in question are actually the
various parts of the windings in the transformer. e.g. if the primary has
many layers of winding then one layer may be closer to the secondary
windings than the others. Hence swapping over Live and Neutral can change
how much mains hash gets though to the secondary, and thus into the rest of
the circuit.

All being well, the makers know what they are doing, take care, and ensure
equipment works fine either way if they've chosen a 'reversable' connector.
But if not... The problem is that makers can be clueless, or careless, or
simply human, so prone to mistakes.

Slainte,

Jim

--
Please use the address on the audiomisc page if you wish to email me.
Electronics http://www.st-and.ac.uk/~www_pa/Scot...o/electron.htm
Armstrong Audio http://www.audiomisc.co.uk/Armstrong/armstrong.html
Audio Misc http://www.audiomisc.co.uk/index.html

A good 'record' shop?
 

"Bob Latham" wrote in message
...
In article ,
David Looser wrote:

But FUL's phase "hardware with capability to invert polarity via such a
mains interface" is just so much meaningless gobbledegook.

I agree it is poorly worded and even technically incorrect but I'm sure we
all know what he meant.


Well I *guess* that he he was trying to obscure the obvious, that a
reversible connector can be reversed, with a load of psuedo-technical
mumbo-jumbo.

David.