Furthermore, all hi-fi, and much other
equipment, relies not on the RMS but on the peak
value, for which suppliers are wholly non-cognisant.
Degraded sound may be caused by the peak value being
way low or high, while the RMS value remains relatively
within limits.Common such
loads in urban areas are the hundreds of idiot-designed
low voltage halogen lamps, the problem being caused by
saturation in the associated low grade, penny-pinching
E-I core transformers, often one per lamp. Along with
the halogen content and the UV rays, a less ecological
form of lighting (and potential way to start a house fire)
would be hard to contrive. Meanwhile, the circulating
‘triplen’ (third, alias 150Hz) harmonics generated by
hundreds of stressed little transformers adds distortions
to the supply that are largely un-filterable. The cheap
switch-mode regulators now frequently substituted for
those toroids are even worse.
In your home, halogens and low energy fluorescent
lamps are OK if you can switch them off when listening.A simple test: with a warmed-up and playing and just
listened to system, and at a time of day that listening
occurs, switch off everything else in your house. Check
the sonic difference. Then power them back up. Try this
again when you know the neighbours are away. Sonic
changes observed indicate the severity of any mains
pollution caused by the immediate environment, and the
interactions that might result, but not more generic local
pollution. No change is the best result for this test.Let’ s reiterate: The AC supply is public, and its capacity
is not finite. Thus, it is obvious that most every device
connected and disconnected to & from the mains,
must affect it, in some or other way. The effect/s may be
subtle, but may be shown by advanced measurements,
calculations, or inferred from principles. Seemingly
subtle effects may be magnified by resonances, or raised
above the noisefloor into audibility when that noisefloor
lowers.For
example, if a CD player pollutes the supply by more than
it needs a clean supply, then placing it on the incoming
side of a single PC will be valuable. With just two PCs,
the permutations increase; a large PC could deal with
just the amplification, with the low level items fed from
a second, smaller PC. In a true dual-mono system, equal
large PCs could handle each stereo side. Or the 2nd PC
might be used to isolate the CD player from the main
supply, double-isolating it from the system proper.Many American designers don’t
realise that their 60Hz transformers, which are 10%
cheaper to make, are under stress when used on 50Hz
mains (in the UK and EU-land), and the stress doubles
when the voltage is remotely above rating.But the overall ‘cocktail effect’, of, for example,
broadband connections spraying RF out of home
phone cabling, and ‘wappy’ wireless products spraying
RF around neighbourhoods, let alone umpteen
mobile phones, or idiot schemes trying to radiate
broadband and TV to us down the AC mains supply,
will, I predict, make the attainment of high-end sound
increasingly dicey in urban and even suburban homes.
RF getting into a high-end system is easily systemic,
meaning that eradication can be complex and require
strong custom solutions.Καλά, μιλάμε για απίστευτη σαλάτα, από αυτές που έχω αποθηκευμένες στο δίσκο για να διαβάζω και να γελάω. Δεν ξέρω, όμως, αν αυτός είναι χειρότερος από ετούτον. Τί λες;Our hi-fi components and systems are steadily and
incrementally improving, giving better analysis and
appreciation of the music we enjoy. At the same time the
potential quality improvements threaten to be undermined
by increasing pollution of the mains electricity on which
are totally reliant.


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