Bejazzled York logo

Bejazzled

Hifi Forum and musings


Mains cables - there is a difference - Mike Ashdown

It all started when I decided to tidy up the wiring at the back of my hifi system. I used to work in the electronics industry – built my own valve hifi in the past - and I am still handy with pliers, cutters and screwdrivers. So I bought a few metres of mains flex – cotton covered, rubber insulated iron cable; I chose this because it would be flexible and hard wearing. I bought new mains plugs and “kettle plugs”, and after an hour or so, had myself a set of cut-to-fit mains plugs. These plugged into a cheap distribution strip with a metre or so of cable, in turn plugged into a wall socket.

I sat back to admire my labours and listen to a record: I was surprised to hear that the system sounded quite different. Not just a bit different: quite different – more thin with a high frequency emphasis. High frequencies sounded clear and detailed – but too forward.

The effects of cabling in the hifi community is not new. Interconnects and exotic speaker cables are easily available and remain controversial. But my knowledge of electronics made me reluctant to believe that a mains cable could affect things much at all. At mains frequencies the affects of inductance and capacitance could not be much; neither could the resistance. Besides we are led to believe that the designers of hifi devote a lot of effort in producing sophisticated power supplies within the equipment. The electrons scurrying around amplifier circuits are much cosseted, smoothed, stabilised and generally protected from the cruel world of savage fields and transients outside. Seemingly not; my ears told me otherwise.

I put the old cables back (the ones which came with the individual units) listened to more music and started to research the subject on the internet.

Indeed, this is a well-trod path, particularly in do-it-yourself area. I searched a number of web-sites. Some stated that the effect of cabling was non-existent, and that those who claimed it was were either out to rob you of your money, or were quasi religious fanatics deluding themselves.

Others listed numerous tweaks and projects for the would-be believer.

One described an effective cheap cable made of solid core screened satellite antenna cable. I made up a couple of leads using this method. One from the mains socket to the power distribution sockets (in-line mains sockets on an extension lead); the other was in the form of a “kettle lead” to plug in the back of a hifi unit. Both had a similar effect: the sound was bright, almost tinny. The bass appeared deeper but less defined. Transients were blurred.

I tried a similar lead using solid core mains cable – the sort that houses are wired with. This had the same effect, although more so – the sound was twangy. Why this should be when so many metres of this cable carries the power from my electricity meter to the power socket is hard to explain. But the results were not imagined. In fact, after all my labours I was keen to convince myself that the system had been improved. However, it hadn’t; it was just different.

I then searched the web for commercial solutions. Many of the most expensive cables seem to use precious metals to a greater or lesser extent and frequently have a metal shield of some sort to the cable, creating a sort of three cored coaxial cable.

I did not have any of this available so I did the next best thing. I stuck aluminium foil to an existing standard hifi “kettle” lead with double sided sticky tape (a delicate process), and finished it with a layer of duck tape for protection. The resulting sound was impressive: not apparent colouration of tone, but much improved clarity and focus. Bass notes were well defined. Even my non-believing wife commented that the hifi sounded particularly sweet. I have since gone on to cover the cable between the mains socket and the distribution block with aluminium, resulting in a continued improvement.

Other web sites offer further advice. Most seem to agree that unswitched outlets are better than switched ones. This presumably is to avoid the risk of contact resistance in the switch. Similarly, the use of mains fuses are frowned upon in mains plugs. Some writers suggest soldering a link across a fuse holder (a dangerous practice for individual, guarantee, and, God forbid, the loss assessor of the ensuing house fire); others go to car boot sales and purchase old fashioned 15 amp plugs and socket, which were found in the kitchens of the 1950s.

Two sites state unequivocally that the left hand socket in a twin wall socket always sounds better. This allegedly has something to do with the positioning of the earth plate within the socket.

Other sites stressed the importance of burning in new mains cables. A speedy way of doing this is to pass a high current through them, such as by plugging kettle leads into a kettle, or using a distributor block to power and electric fire for a while. (checking that the fuse within the plug is not over-taxed).

While some of the above tweaks may be minimal or fanciful, I am in no doubt that my own hifi system running on the mains supply available to me at my home is noticeably dependent upon the mains cables used. It seems to diminish the slight fluffy sound that all solid state amplifiers seem to bring to music. Although my Linn system is only an approximation to my old valve system - to my ears, correct mains cabling brings it a significant step nearer.

NB MAINS VOLTAGES CAN KILL – NOT JUST YOU, BUT YOUR FAMILY. DO NOT WORK ON COMPONENTS THAT WORK AT MAINS VOLTAGES UNLESS YOU ARE QUALIFIED TO DO SO

Go back to Hifi Forum main page Go to the top of this page Website by Agnes