Everything you ever wanted to know about POWER

(better grab a coffee... this is a long one).

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Any 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.

Power Basics:-
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.

AC or DC?
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.

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! DC primarily 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.

50Hz or 60Hz?
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.

Clean 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.

Sine waves:
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.

Clean power devices roughly fall into four categories:-

Filters: That attempt to scrape noise off of the mains to leave us with a sine wave.
Regenerators: That de-construct and re-construct the mains to produce a sine wave.
Conditioners: That analyse the mains and inject 'anti-noise' to rehabilitate the sine wave.
Generators: That convert non-mains power into a sine wave (e.g. chemical, gas, battery).

Filters 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.

Regenerators 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.

Conditioners 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).

Generators 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.

Confusion Factors:
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.

Second, there's combinations of functions that blur the boundaries – a regenerator might contain filters for example.

Third, 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...

GFIs and CBTs:
Like the safety switches in your home - OH&S stuff.
Balancing Transformers:
Supposed to reduce noise by cancellation – individual results may vary.
Isolation Transformers:
Not much different from the above but can sometimes reduce hum.
Stepdown Transformers:
If you have one or more components from countries that don't use 240V.
Surge Arrestors:
Might save your gear from a minor voltage spike (but probably not a big one).
Voltage Stabilisers:
Continuously adjust voltage – useful in areas where large variations occur.
Distribution Box:
A glorified power board really but somewhat fancier than your Kambrook.

Do they 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 than others,
Some components will show you differences between power cables and some won't,
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,

Underlying Mechanisms:
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 necessarily so”.

My 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.

So 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 doesn't?

Or – 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?

Or – 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?

Or – 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?

Or – could it be that the expensive cable just has better quality plugs on its ends?

Or – 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 each other?

Without 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.

And now, for something completely different – "The D.F.M Effect"

There 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.

So 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 strikes again!

Now, 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.

The 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!

Ideal Configuration:
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.

Further notes on related issues.

Edison Connectors:
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.

Most 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.

Voltage Variations:
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 Conversion page.

Voltage Surges:
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.

Transformer Buzz:
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.

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