It all started when I decided to tidy up the wiring at the back of my hifi
system which consists of a Linn turntable, tuner, preamplifier, power
amplifier, tuner, speakers and a Naim CD player. 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.
Throughout my experiments I found that cabling affected my Linn power
amplifier more than any other component.
I pursued one other tip that a web site offered. It is suggested that
Linn LP12 turntables are responsible for polluting the mains and
affecting the sound of a system (even when the deck is not the source).
This is put down to the presence of Valhalla or Lingo circuitry which in
effect produces its own supply of alternating current. So I followed the
advice and have plugged my LP12 into an outlet on another wall.
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
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