reasonable person would imagine that powering a domestic sound system
should be a fairly straight-forward affair and it should
be but when we start to look for up-market cables and power
conditioning devices, things get complicated pretty quickly. I
get asked about this stuff almost every day and I find it's pretty
easy to explain to someone with a background in engineering or an
electrical trade but a lot of non-technical people struggle with
some of the concepts involved. With that in mind, I'm going to briefly
outline some electrical basics to begin with so that hopefully,
the rest of what follows should make some sense and answer most
of your questions along the way.
What's a Watt? A unit of power which is the ability to do some work.
Named after the guy who invented the steam engine, the Watt is used
to measure power in all kinds of things. In electrical systems,
power in Watts is the product of voltage and current. Volts x Amps
= Watts Example:
An American product that runs on 120Volts and has a 2Amp fuse can
consume 240Watts when it's converted to Australian power
at 240Volts, it has a 1Amp fuse and can consume 240Watts.
Direct Current runs around a circuit in one direction only
Alternating Current constantly changes direction. Metaphorically,
a bicycle illustrates the relationship nicely the movement
of the chain and wheels is like DC and the movement of the rider's
legs is like AC. The pedals covert the alternating leg movement
into direct wheel movement and behave a bit like an electrical device
called a Rectifier which converts AC into DC. The opposite
of a rectifier is called an Inverter which converts
DC into AC.
is the best way of transporting electricity from the power station
to your home because it can travel long distances without much loss
and its power can easily be transformed to energise all kinds of
equipment and appliances using guess what... a transformer!
comes from chemical sources such as batteries and solar panels which
must be connected to an inverter before they can power AC appliances
in your home.
Frequency, measured in Hertz (Hz) or Cycles Per Second (c/s) is
about how often the AC changes direction in Australia, it's
50 times per second and in the USA, it's 60 which has to do with
how fast the generators are turning at the power station.
Power and Dirty Power:
Clean power from the power station gets 'dirty' on its way to your
wall outlet, mostly because of the thousands of PCs, plasma TVs
and other appliances, each adding a bit of their noise to it. The
purity (or otherwise) of the power supply has the potential to influence
the purity of your system's sound. The
desire to have the purest sound has given rise to all kinds of devices
to clean up the electricity before it gets into your Hi Fi system.
When you get involved with clean power systems, you'll hear a lot
about sine waves. Sine is a Latin word (pronounced 'seenay' in Latin,
but we say it the same way as 'sign') which means 'without'. Without
what, you ask? Well basically, unwanted harmonics and noise. Sometimes
you hear about 'pure sine waves' which is tautology because there's
no such thing as impure sine waves because if they have any other
stuff mixed in, they're no longer 'without'. What
we want from any kind of clean power device is a sine wave with
the right voltage, the right frequency and enough Watts to supply
all our toys.
power devices roughly fall into four categories:-
That attempt to scrape noise off of the mains to leave us with
a sine wave.
That de-construct and re-construct the mains to produce a sine
That analyse the mains and inject 'anti-noise' to rehabilitate
the sine wave.
That convert non-mains power into a sine wave (e.g. chemical,
don't really do all that much because they usually operate at frequencies
that are just a bit too high to effectively restore the sine wave
in any meaningful way. Distribution boards with individually filtered
outlets however, can be useful to prevent digital and power supply
noise coming from things like TVs and Blu-rays being injected back
into your analogue components through their power cords. Filtered
power boards may not offer much in the way of power scrubbing but
many of them do offer some additional protection from surges.
are based on the idea that if you build a really big amplifier and
then feed a low-level sine wave into it, it should be powerful enough
to drive any components smaller than it. This does work but it's
an 'American Monster Truck' kind of solution. Regenerators often
have some geeky features that allow you to tweak voltage, frequency
and sometimes even waveform if you're so inclined.
offer a more elegant solution by allowing the mains supply to do
most of the heavy work and injecting a comparatively small corrective
wave that 'patches' the holes in the power company's waveform and
turns it back into a sine wave. If the impurities in the mains wave
amount to say, 10%, a conditioner only needs to work one tenth as
hard as a regenerator (approximately).
more or less produce power without direct input from the mains.
There are several variations on this theme but usually, they involve
a storage battery, a battery charger and an inverter. The battery
can be charged whilst the audio system is switched off and then
disconnected from the charger to drive the inverter when the system
is being used. The advantage is complete isolation from the power
grid and all of its noise (as long as the battery holds up). In
terms of form, fit and function, these devices are closely related
technologically to Un-interruptable Power Supply (UPS) units for
computer servers and also to domestic Solar Power systems.
Here's a bunch of other stuff that tends to make the whole power
issue a bit more confusing.
First, there's the misnomers... some devices that are called
conditioners are incorrectly named sort of like calling a
fan or an evaporative cooler an air conditioner.
there's combinations of functions that blur the boundaries
a regenerator might contain filters for example.
there's other things like: Ground Fault Interrupters (GFIs),
Core Balance Transformers (CBTs), Balancing Transformers,
Isolation Transformers, Stepdown Transformers, Surge Arrestors,
Voltage Stabilisers and distribution boxes which are all related
to power systems in some way and may exist as separate units or
may be integrated into an all-singing, all-dancing, fully-featured
power gizmo that straddles a couple of categories. For the sake
of clarity, here is an executive summary...
Like the safety switches in your home - OH&S stuff.
Supposed to reduce noise by cancellation individual
results may vary.
much different from the above but can sometimes reduce hum.
If you have one or more components from countries that don't
Might save your gear from a minor voltage spike (but probably
not a big one).
Continuously adjust voltage useful in areas where large
glorified power board really but somewhat fancier than your
work? Yes and no well maybe sometimes let's
just say: Individual results may vary.
The variables are as follows:
Some audio components are clearly much more sensitive to cables
Some components will show you differences between power cables and
In terms of sonic properties, some power cables seem to be more
effective than others,
Interactions between any cable and any given component may not be
repeatable on others,
Sometimes what seems to be going on and what's actually happening
may be two different things. For instance, you might assume that
the benefits of high-end power interconnects result from superior
conductivity well, to quote George Gershwin: It ain't
first 'WTF' power cable moment came when I was trying to track down
a mysterious instability in a high-end CD processor. The processor
worked flawlessly by itself so I was looking for possible interactions
with other elements. I asked the client to bring his interconnects
in to be checked. When I attached his hideously expensive power
cable and plugged it into my $5 Clipsal power board which was plugged
into another $5 Clipsal power board which was plugged into some
40 year old house wiring, I did not expect it to behave any differently
to the generic computer-style cable I had previously used. I was
actually able to see some reduction in background noise on my oscilloscope
using the expensive cable and was forced to conclude that somehow,
the structure of this cable made it behave more like a filter than
a super conductor. I wasn't expecting that.
let's imagine you have a mains interconnect you paid say, $1000
for and you have an opportunity to audition an interconnect worth
say, $2000 and you decide that the more expensive cable sounds better
than the cheaper one. Now, would you assume that the difference
is because the more expensive wire is made out of more precious
material or that it has some magical properties that the other one
could it be that the amp needs a good ground connection to
sound its best and your original cable has a slightly dirty ground
pin and just needs a bit of a clean?
could it be that the amp needs to be floated from ground
to sound its best and the expensive cable has a dodgy ground pin?
could it be that the new cable is shielded and radiating
less electromagnetic interference into all of the other cables around
the back of your system?
could it be that the expensive cable just has better quality
plugs on its ends?
could it be that your amp is just a little bright and the
new cable is just a little dull and the two just seem to complement
access to a fairly sophisticated test set-up, there's no way to
determine precisely what is the mechanism underlying the perceived
sonic difference (notice I didn't say improvement?) This
is why people can get a bit perplexed sometimes when they think
they know the characteristics of a particular cable and then find
it behaves in a totally unexpected manner in a different system.
now, for something completely different "The D.F.M Effect"
was a British television series that used a Candid Camera type of
format but it was produced by behavioural psychologists. One time,
they bought two identical no-name brand chocolate cakes and set
up a taste test in the shopping mall. One cake was labelled chocolate
cake and the other was labelled double fudge mudcake.
All of the shoppers surveyed agreed that they wouldn't mind paying
a bit more for the mudcake because of its superior taste and texture!
This experiment was was intended to illustrate the degree to which
expectation can modify perception.
what if a guy walks into a shop on a Saturday and buys a bunch of
fancy power cables with a view to rewiring his system on Sunday.
First, he discovers that everything has to move about 100cm further
from the wall because his new cables have the bending radius of
high pressure hose. This move reveals an unexpected quantity of
dust and dead insects so some cleaning takes place along with some
tweaking of the setup to get all the cables to sit just right. By
the time he's ready to seriously audition the new configuration,
it's dinner time and any acoustic memory of what the system used
to sound like is now at least 24 hours old. So, do we think this
guy's expectations are psychologically primed to modify his perception
of the result? I mean, if he doesn't perceive a big improvement,
he's going to feel like a complete wood-duck for spending all that
money and his wife's gonna kill him! The Double Fudge Mudcake effect
it could be that the system actually does sound better or
not or maybe exactly the same but because nobody has the
capacity, in their own home, to A/B compare two identical systems,
one with cable A and one with cable B in a double blind test, there
is no empirical proof. I'm
not saying that cables don't make a difference because, in the right
place, they can really put the icing on the cake but, in the absence
of any standard, empirical test, the manufacturers are playing to
a captive audience and they know it.
Emperor's New Clothes Syndrome:
Our cables are so uncommonly fine that they a have a wonderful
way of becoming inaudible to anyone who is unfit for his office,
or who is unusually stupid (with apologies to Hans Christian
Andersen). This is all about perception: Can you hear what I hear?
Or should the question be: Can your ears detect it and can
your brain process it? I've found that it's better not to
assume that anyone else's hearing is the same as yours. Personally,
I am particularly sensitive to some types of distortion which others
don't seem to mind at all. I also know what's going on in my head
when I see what I call the colour blue but I have no idea what's
going on in your head when you see what you call the colour blue.
Maybe you will get a major revelation by changing a few cables and
that's great... and if you've read this far, you'll have a fair
idea of the many variables that might come into play and
you'll be wary of the dreaded D.F.M effect!
It is not the purpose of this article to promote any particular
power product. In general terms, if you own (or are considering)
a device that can provide clean power, you probably don't need to
spend quite so much on cables why? Because if the power source
is already pure and clean, all you need is to get that pure energy
to the component(s) and an expensive, esoteric cable is unlikely
to make that pure power any 'more pure'. To do the system justice
however, the cable(s) from the clean source should be of reasonable
quality with good connections and shielded to reduce the possibility
of noise induced by electromagnetic radiation. If the clean source
does not have multiple outlets, you will also need a good quality
distribution board, possibly using Edison connectors (see notes
below). Personally, I wouldn't waste a sexy power cord on the inlet
to the clean source as any device worth its money should clean up
the power from your mains outlet - so putting 1.5 metres of precious
metal on the end of 40 metres of dirty old house wiring from the
fusebox is unlikely to provide much of a dividend. Be aware that
some components will always work better when powered from the clean
source and some will work better when powered direct from the mains.
In general, source components and preamps will usually work better
with a clean source but large power amps will sometimes sound better
when powered direct from the wall outlet. This is important to know
because there's no point in buying a massive device that's big enough
to power some huge amp if it's going to sound worse when you could
conceivably get a better result from a smaller device that supplies
just your front-end components.
notes on related issues.
One thing you'll almost certainly discover is that just about everything
that looks any good doesn't have Australian plugs and that's just
because of the small size of our market. The American standard (Edison)
type of connector and cables are quite OK to operate at 240 Volts
which is handy to know if you're planning a special power distribution
system. Standardising the connections within your system to Edison
is a cost-effective solution that opens up a smorgasbord of options
because every company that makes audiophile-grade plugs and sockets
makes them for the U.S. Market whereas there's only one, maybe two
high-end plugs for Australia and no sockets that I'm aware of.
of the good distribution, filtering and conditioning products as
well as cables will have Edison connectors by default and may or
may not have any Australian versions available. Almost all of the
good components produced today have detachable mains cords so you
can still connect any of them to a standard outlet via a standard
cord if you wish. Components with fixed cords can usually be converted
by having an IEC receptacle fitted, if required.
Officially, our mains voltage is supposed to be 230 Volts which
presumably, is intended to bring us into line with the European
standard which has supposedly ratified all of the voltages across
that continent. In the past they were anywhere between 220 and 240.
In practice, the only Australian state that operates on the 'official'
voltage is Tasmania (as far as I am aware, but this information
may be out of date by the time you've read this). The rest of Australia
still operates on the old British standard of 240 Volts which may
vary as much as +/-10% under some conditions. Products designed
to operate on our mains must allow for this degree of variation.
For more information regarding voltages and conversion of foreign
equipment, see the Voltage
A surge can be caused by a few different things but a tree falling
on power lines is probably the most common cause. Think of it as
being like an explosion where the intensity and the degree of damage
depends both on the size of the bang and your distance from the
bang. The closer you are to 'ground zero' the more it's going to
hurt. Surge arrestors will protect you from surges in more or less
the same way as a bull-bar will protect you from front-end collisions
if we're talking about shopping trolleys, bicycles and small
kangaroos, you're OK but a big truck can still kill you!
If you are very close to the site of an incident resulting in a
surge, your surge arrestor will be the first thing that gets vaporised
but if you're a bit further away, it might save some of your
gear. If lightning strikes the pole in front of your house however,
the first thing you'll notice is a big hole in the wall where the
fusebox used to be and everything connected to that will be toast.
Bottom line? The best form of insurance against voltage surges is
-- insurance. Power companies are insured against damage claims
but if your gear is very esoteric and high-end, you might have a
bit of frustration when making a claim because they just don't understand
anything that didn't come from a department store.
Some components usually imported ones will produce
an audible buzz, not from the speakers but from within the unit
itself. This noise comes from the transformer and possibly its mounting
which can include parts of the chassis. Sometimes, the buzz is due
to a poorly constructed or cheap transformer and this can be difficult
to fix. At least some of the noise however will be due to the 'dirt'
in the incoming mains i.e. distortion of the sine wave resulting
in extra harmonics which excite resonances within the transformer's
structure. Feeding clean power into such a component can often reduce
the buzz significantly.