Decibel Dungeon


Introduction

Hi-fi cabling is one of the most controversial topics in hi-fi circles, although much less so now than a few years ago.
At one time, we all connected our hi-fi together with the skinny cables supplied with the equipment and were quite happy with the bell-wire which joined our 'speakers to our amplifier. Then somebody, somewhere (I wonder who it was) started trying different types of cables and suggested that they could affect the sound of a hi-fi.
At first, many people ridiculed this suggestion including many who were qualified electronics engineers. Perhaps what annoyed the doubters most, was the plethora of over-priced cables which suddenly appeared on the market and sold with all sorts of ridiculous claims. However, as time passed and more people discovered that the type of cable does affect sound quality, the market for exotic interconnects and 'speaker cables grew and the arguments diminished.
The arguments have resurfaced recently as it has been suggested that apart from interconnects and 'speaker cable, the type of cable connecting equipment to the mains electricity supply can also have an effect on sound quality. Many quite respected hi-fi experts still dismiss this theory as rubbish.
I should state which side of the fence I am on regarding this issue so let me say that from my own experiments, I have found that different types of cable (including mains) do affect the sound.
Before I receive floods of e-mails taking issue with me, I would like to qualify what I mean when I say 'different'. This applies to all hi-fi cabling, not just mains cables.
The explanation generally given for the effect of cables on the sound of a hi-fi system goes something like this. Any length of wire or cable has properties such as resistance, capacitance and inductance. These are also the properties which are used to build electrical filters such as loudspeaker crossovers and tone controls. An electrical filter of this type attenuates certain frequencies while allowing others to pass. The result is an effect on the overall tonal quality of a music signal. So the wire or cable is acting like a filter.
Many will still argue that the filter effects caused by a short length of cable are not enough to make an audible difference and it is true that any differences are more noticeable with longer interconnects and 'speaker cables.
I'm no scientist or engineer but I can detect differences in interconnects, even as short as nine inches.
So I accept that there are differences between cables but I don't subscribe to the idea that one cable sounds better than another. A cable might sound good in one system but not in another. Bearing in mind that the sound we hear from our loudspeakers is the result of the signal traveling through a variety of cables, connectors and electronic components, it is impossible to praise, or blame any one as there are so many variables.
Sometimes, there is a type of cable which does seem to work well in a majority of systems but most of the time, the only way to know if something works in your system is to try it. I have certainly found it worthwhile to try as many types of cable in my system as I can although I caution anyone against getting too carried away with cable experiments. The most common mistake in hi-fi is not realizing the difference between 'different' and 'better'!

Interconnect wiring
Don't confuse the two conductors

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Experimenting

There are two ways to experiment with cables: you can buy or borrow commercial examples or make your own. Even if you can find a supplier who will let you audition different cables before buying them, it will still involve visits back and forth to the store, or postage costs so I recommend the DIY approach.
If you do prefer to go with the ready-built cables, don't get fooled by all the hype. A popular trick is to offer '200 interconnects for only 80'. Believe that and you'll believe anything. After all, an interconnect is a piece of cable with a simple plug on either end, material cost about 10 on average. Sure, there are overhead costs like marketing, and profits for the dealers, but the same goes for all hi-fi. It's getting silly when an interconnect costs more than an amplifier or CD player!
Making up your own hi-fi cables, whether interconnects, 'speaker cables or mains leads is not at all difficult and is a good way to get started in DIY hi-fi. The components need not cost too much and you don't need to work with high voltages (if you avoid mains cables). Just make sure that you don't create a short between the conductors and you can't go wrong.
At present, I don't intend to include any specific cable recipes as there are plenty to be found on the internet. You may like to start on the TNT site.
Worm I will however, make a few general suggestions to start you off.
  • I've tried silver-plated cables and found that they sound different but not necessarily better than those with a plain copper conductor. Unless you've got money to throw away, I suggest sticking to copper conductors, at least while you are in the experimenting stage. The insulation used on wires is also a factor in how the wire 'sounds'. Materials such as PTFE are considered better than the usual PVC types (although they are usually only found on silver-plated conductors) However, I have now been told that PTFE/Teflon has a 'memory effect' and is therefore NOT recommended in hi-fi!
  • If you do use silver-plated (or solid silver) conductors, make sure you use silver loaded solder.
  • In my experience, a plug is a plug. I've tried all sorts, from the very cheap plastic types to expensive gold-plated ones. I don't think that there is any difference between them as regards sound quality and providing that the pins make good contact with the sockets they all seem to work fine. I now use the cheapo plastic types unless I need a larger cable entry which is necessary when using large diameter cables.

    TIP - Some of the larger cable configurations can be nigh on impossible to solder into even the larger phono plugs. An alternative is to use the larger XLO type plugs and sockets. Even if they don't improve sound quality, they are a lot easier to solder to!

    Hi-fi interconnect plugs
    Phono plugs and XLO type plugs (right)

  • Some of the readily available coaxial cables work well as interconnects or 'speaker cables.

    TIP - A coaxial cable known as RG58 works very well as a 'speaker cable. I used two lengths per 'speaker, one length with a solid conductor (RG58BU) and the other with a stranded conductor (RG58CU).

    Coaxial cable
    A typical single conductor coaxial cable

  • Use screened cables if your hi-fi is situated near equipment like TVs and VCRs. Kitchen foil works well when used with a drain wire. The drain wire is simply an uninsulated wire running the length of the cable and in contact with the foil. It is then soldered to the ground side of one of the phono plugs.
  • When you discover a cable design which you like, see if you can refine that design to make it better.
  • Use heat-shrink sleeving to finish your cables off neatly.

A trial of IBM Type6

Having finally managed to get hold of some IBM Type6 cable (thanks to Peter Bradley) I eventually got around to soldering on some phono plugs and trying out the results between my preamp and poweramps. The length of these interconnects is 1.4 metres.
The following coments are based on listening to these cables in MY system and should be read accordingly. The sound was well controlled and the bass lines defined but also integrated with the rest of the music. There is more bass than you would get with the 'bog standard' interconnect supplied with hi-fi equipment.
If I had come across IBM Type6 in my early days of playing with cables, I may well have settled with it on a long-term basis. However, repeadedly swapping between them and my 'reference' leads, I noticed that the latter were quite a bit more 'open' or transparent. Having said that, it is only fair to point out that the IMB Type6 leads had taken about 30 minutes to assemble while my 'reference' leads had taken the best part of a day. So, if you are looking for an 'easy' DIY interconnect, I would recommend the IBM Type6 as a very good starting point.
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Mains cables

If you do want to try your hand at mains cables, there are a few extra points to remember.
First, mains cables will carry high voltages, high enough to kill you and damage property if you get things wrong. So, please take note of the following:
  • Don't attempt to build mains cables unless you are absolutely sure that you are competent to do so.
  • Always make sure that the wire you use to construct a mains lead is rated for the current which will pass through it. Unlike other hi-fi cables, any old wire just won't do.
  • Make doubly sure that the conductors are well insulated and that you have no short circuit.
  • If your equipment does not have a detachable mains lead, think carefully whether you want to open it up and remove the captive lead. Doing so will invalidate any guarantee.
  • If you are tempted to think that 'bigger is better' don't forget that the finished lead also needs to be flexible!
  • Also remember that you will have to fit the conductors into some sort of plug so don't have them too large.
  • You don't actually have to build a cable, try using something as it comes off the reel. My best mains lead was formerly attached to an electric cooker and already 'burned in' (see below).
  • Many people have reported very good results using a screened cable like the Raydex CDT (part 235-210)from Farnell Electronics. (Unfortunately, this is only sold on 50 metre rolls)
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Burning in cables

No, don't go off and throw your precious hi-fi cables into the fire. Burning in, in this case means passing a current through a cable prior to actually using it for its intended purpose. I have not seen a scientific explanation for why this should work but it could be something to do with the current aligning the molecules in the metal conductors. As the molecules become more aligned, they present less of an 'obstacle course' to the electrons flowing through them.
When you burn in a cable it is usual to use a higher current than the cable is expected to conduct when in use. Be very careful though, if you intend to burn in any cable, make quite sure that the conductors AND insulation are rated to cope with the burn-in current or you are likely to see them go up in smoke. However, if you have built a hefty mains lead, it may benefit by being connected in series with something like an electric fire. Make sure that you use the correct methods of connecting the cables and that everything is properly insulated.
Just how long you do a pre-burn in is a good question. If burning in does work then I suppose the answer is 'as long as possible'. Of course, the object of the exercise is to use the cable in your hi-fi so you'll have to draw the line somewhere.
Of course, any cable will burn in while in use, it's just that it will take longer with the lower currents involved with interconnects and 'speaker cables. The choice is up to you but if you go for a pre-burn in, do heed the cautions above.

TIP - When you are auditioning a 'new' (DIY) interconnect, allow at least 30 minutes in use before you make any assessment of the sound quality. The same goes when making any assessments where a soldered joint is involved. It seems that it takes a while for everything to 'settle down' and the sound changes over this period (usually for the better).

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More cable links

The Missing Link sells cables but also offers all the raw materials for you to build them yourself at a considerable saving on the ready-made item. Worth a look and they will also offer a plating service for plugs etc.
If you don't want to DIY, CAD have a good range of ready-made cables.
Cables suitable for phono stages
A good read on audio cabling
A guide to loudspeaker wiring
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