The Mains Mans Tips & Tweaks, The Mains Supply

The Mains Supply

How many times have you sat back in your favourite listening chair around midnight or the early hours and noted just how spectacular your hi-fi system sounds? Then have you noticed how the sound deteriorates early evening? What you’re hearing is not just your system, but the mains supply. The bad news is, things are going to get much worse, but there is something you can do to get that ‘Midnight’ sound all of the time. Know Your Enemy!

What you’re fighting in your mains system is not just one problem, but a number of problems, all of which affect the sound of your system. The first problem is earthing, or rather a lack of. In older homes, or homes that haven’t been rewired for the last 20 or more years, it is not unusual to find that your earth is very poor. This can manifest itself as background hash during inter-transient silences, haziness around your images on the soundstage and sometimes glassiness to the midrange and high frequencies. The preponderance of low voltage power supplies especially in PC’s, satellite receivers, power supplies etc. also do a lot of damage to mains integrity and deteriorate sound quality still further.

Further problems in the mains can be found due to the age of the mains grid itself. Quite simply much of the equipment in the National Grid is old, and it’s operating efficiency is not what it used to be. Furthermore the ability of this equipment to deliver tightly regulated 230V / 50 Hz mains is deteriorating. It should also be noted that when the overhead power lines used today were originally installed, the air did not contain the RFI and EMI as it does now, hence the power, before it reaches the substations, is already polluted. We have mainly mobile phone masts to thank for that.

Due to current regulations the voltage delivered to your home can be as much as +/- 10% and this in itself can severely affect the ability of a power amp or A/V receiver to meet it’s specifications. The result is voltage that can swing between 207V and 253V. What is worse is your supplier doesn’t have to do anything about it. Today’s homes and offices also have far more low voltage equipment in them than ever before. The power supplies which drive these devices (like those in an audio system) only use the top and bottom of the sine wave to actually power them. Therefore the hypothetical 50Hz Sine Wave that should be coming out of your socket would, on an oscilloscope, actually have its peaks and troughs flattened off as it’s these peaks and troughs that drive devices that use switch mode power supplies found in so many devices today.

The next problem is the insidious duo of EMI (Electro Magnetic Interference) and RFI (Radio Frequency Interference). This pair are also on the rise with their crimes getting grander by the year. Mobile phones, wireless LAN’s, digital radio and digital satellite TV broadcasting all attack your mains. The aforementioned offenders cause a hideous soup of RFI that your mains just loves to transmit into your audio equipment.
Finally there is a problem of relationship counseling between components across the mains – with many digital components throwing all kinds of noise straight back into the mains supply that then drives your analogue components. This is like having an EMI & RFI source right next to your analogue components. Your Saviours!

It is only in the last few years that the damage which all this mains pollution can do to the final sound of your audio and home cinema system has been recognized and addressed. Fortunately there are many solutions to help deal with mains problems, these range from correct dressing of cables, to highly sophisticated mains regenerators, costing several thousand pounds, which literally give you your own power station in your listening room. In between these two extremes are a variety of mains filters, isolation transformers and mains cables, all of which when used appropriately can yield a big improvement in the sound and performance of your system disproportionate to the costs involved.

For most systems you should consider filtering the power to all components as an essential first step. If you have the budget for a dedicated mains spur please consult your local electrician and run a quality mains power cable from your mains fuse box to a separate consumer unit which in turn is connected to a wall socket near to your hi-fi.

If you cannot fit a dedicated mains spur then at least use an audiophile quality mains wall socket like the Furutech FP-1363., this will improve conductivity and because it is un-switched with no on/off lights will also prevent further ingress of RFI into the mains system. Once the wall socket/s have been addressed the next stage is consideration how to connect your hi-fi system from the wall, dependant on your budget a mains regeneration system costing thousands of pounds can be considered but in the opinion of the author of this blog a far simpler solution costing a fraction of the previous cost will provide an effective solution to a dirty mains supply, the answer is a DC blocker. DC has resided on the UK mains supply for many yeas but not until recently has it been acknowledged and understood. Isotek have addressed the problem with their Syncro Power Cord . A DC blocking mains lead will solve many of the issues that a modern hi-fi system has to face with regards to the mains supply. As the owner of Mains Cables R Us I commissioned my own manufacture of en effective DC blocker called The Excelsior, a white paper has been written about the testing of it.

With The Excelsior or any other DC blocker in place attached to a good quality mains extension block or mains filtering unit such as the Isotek Aquarious or Isotek Sigmas you will have done virtually everything possible to supply your equipment with the best mains supply possible. With these products costing from £500 for high quality, system wide treatment, you will receive a significant improvement in sound (and picture) quality. Support this filtering with a fully shielded mains cable that features a high quality IEC connector from the likes of Furutech or Oyaide and you have already addressed a significant spectrum of mains noise. As your expenditure increases you will find the problem of inter-component interference is addressed through complete isolation of each socket. Further improvements will be wrought by plugging all of your components into isolation transformers, which effectively block noise movement into and out of your equipment whilst providing a very high standard of mains purification. Where nothing but the very best will do mains regeneration is the ultimate solution, giving each component it’s own dedicated power supply. Even at this price point the costs are easily justified once you hear the incredible improvements in sound quality that this sort of equipment can achieve.

You would not run your car on dirty petrol so don’t expect your hi-fi system to perform at it’s best without a clean mains supply. All cables are system dependant, let me know any time if you would like some advice on cable matching to your system.

With a few simple steps you can get the midnight sound, anytime.

David Brook