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Merlino: DIY mains cable

[TNT Merlino]
[The Magician]
[Italian version]

During this last decade a pletora of special audiophile mains cables have invaded the HiFi market, causing many skeptical reactions among audiophiles.
Many HiFi enthusiasts still don't believe in the improvements that can be achieved by using a special interconnect or speakers cable, you can imagine the reaction when the first special mains cables appeared...
What the h@#l could a mains cable do to my HiFi system? This was the main(s) :-) question. I'll leave the answer to a separate article, inviting you to read some of our Inter.views where famous HiFi cable designers explain why a mains cable does have some influence on the sound of a system, by now I'd like to propose you a cheap and easy to build mains cable, called Merlino (The Magician).

The problem

HiFi cables are normally expen$ive and, God only knows why, audiophiles prefer a brass or gold plated knob to a special interconnect or speaker cable.
Furthermore, cable tests are not easy to do at home, since normally dealers won't let you bring home miles of special and expen$ive cables so that you can realize that they actually make some audible difference.
So, usually, you are forced to BUY a cable and then TEST it into your system...and not always the change is for better. Testing mains cables is even harder, since the differences are normally subtler and the break-in period is longer.
So what should you do to test if a mains cable can make any difference to the performance of your system?

The Solution

Build a mains cable by yourself, preferably spending almost nothing so that, even if you can't hear any difference at all, the amount of money spent on the experiment is negligible.
The next step is then browse your TNT-audio magazine searching for good and cheap DIY projects.
The Merlino DIY mains cable is the answer. A rather old answer since this project has been on-line (on the Italian edition of TNT-Audio) since 1996.
Now I've decided to improve the design a little bit and to propose it to the worldwide audiophile crowd.
Many commercial audiophile mains cables work following the same easy principle: a mains cable should be shielded (exactly like the interconnects) to avoid electromagnetic interference being trasmitted and/or received by the cable itself.
In other words one should build a sort of a semi-balanced mains cable.

How can we build it?

Yes, Virginia, I've said this is an easy and cheap DIY project. More sophisticated and difficult to build mains cables will appear in the near future so, if you find the following to be pretty trivial, stay tuned for more complex designs :-)

All you need is a shielded mains cable, easily available at any electric/electronic parts store. A shielded mains cable is a three conductor + a copper (metallic) shield like the one you can see in the picture below.

[CY shielded cable]

The one shown above is available on the RS catalogue (model CY) but any similar cable will work just fine. For example the one used by me (see the Merlino picture on the top of this page) is an industrial shielded cable with three 2.5 mmq twisted conductors and a strong copper shield.
To build your own Merlino you should connect the shield to the ground wire at ONE END ONLY, namely at the end of the cable that goes into the wall socket, leaving the shield FREE at the other end (near the HiFi component, that is), exactly like you do for a semi-balanced interconnect.
The idea is to use the shield to capture the interferences travelling through the cable and GROUND them to earth. The other two conductors must be connected as in a standard cable.
So, since repetita iuvant: connect the three wires to the component plug (or SOLDER them directly into the cabinet, this voids your warranty) and leave the shield free at this end. Then connect the shield to the ground wire just into the plug that will go into the wall socket, the other two wires being connected as usual.
The only difference with a standard 3-conductor mains cable is the fact that there's a shield and that this shield should be connected on ONE SIDE only. I hope it is clear enough. If not, take a look at the picture below that shows you how to connect the wires and the shield into the wall plug.

[CY shielded cable]

Use good quality plugs only and complete your Merlino installing two ferrite rings (or clamps) at each end of the cable like in the picture on the top of this page.
See, for example, the ferrite clamps that are available on the RS catalogue.

[Ferrite clamps]

Now your Merlino is ready to rock: like any other cable even this one needs some break-in, 24 hours are sufficient for the best results (believe it or not...the sound gets better after the break in).

How much does it cost?

An industrial shielded cable like the one used by me for my Merlino costs few $ per meter (2 or 3$ per meter) and 1 meter is normally sufficient for each application.
Add the two plugs (still few $) and two ferrite clamps (10 $, maybe less if you're lucky) and your Merlino will cost you less than 15$, all included.
A big saving can be achieved by using the ferrite rings that are used in any video/printer cable of your old computer.
If you want you can even add a mains filter to get the best filtering/shielding results.

Does it work?

The Merlino is quite surprising, given the price. Amplifiers and CD players seem to sound more dynamic and lively, punchy and articulated. The most audible effect can be heard in the high range, cleaner and more refined, like a veil (oh yes, always the same veil :-)) had been taken off your system, probably it is the effect of the reduced harm caused by the electromagnetic interefences.
Even the soundstage is wider and more focused and the overall sound of your system seems to have much more breath and air.
Of course I've compared the poor-man's Merlino with some commecrcial HiFi mains cable. If one considers the quality/price ratio then there's nothing to compare, definitely.
Without taking into account the huge price difference I'd say that other AC special cables may sound different and not always better. By different I mean that, for example, one of these (Next Tecnos) sounded warmer and smoother than the Merlino but even less open and dynamic.
Another one was pretty similar, just slightly more refined though not as punchy as the Merlino is.
What I'd like to state clear is: the Merlino isn't the best AC cable ever made nor it is a serious contender for the ultra-expen$sive cables that cost thousands of dollars.
It is a simple and cheap DIY project that can make the approach to special mains cables easier. The audiophile who finds the Merlino to be an audible improvement over the stock mains cable could be THEN seriously interested in testing and evaluating (and hence purchasing) better and more sophisticated mains cables.
Of course, not necessarily a more expen$ive cable sounds (always) better of a cheap DIY design...every improvement should be evaluated by means of serious and extensive listening tests, as usual.
Also, one should be aware of the fact that the effect of any cable into a stereo system is strongly component+ears+room dependent and that for mains cables one should add even another variable: the mains quality of your house.


Now, PLEASE, before hitting the mailto below and sending me dozens of messages and flames yelling that a main cable can't make ANY difference I'd suggest you to take a deep breath, relax and go to the nearest hi-end dealer and ask for a comparision test between a special mains cable and the stock one.
Everyone I know who has made this test, even if strongly skeptic, now swears by the importance of a good mains cable inside a GOOD HiFi system.
And I mean, inside a GOOD HiFi system because if you think that a 10$ (or 1000$) shielded cable will turn your '80s HiFi rack into a thousand dollars HiFi system...well, you should have your head checked by a trained technician ;-)

© Copyright 1996-98 Lucio Cadeddu

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