Terminated interconnects are used to connect audio sources to a pre-amplifier and the pre-amp to the amplifier, as well as other components like subwoofers. Without interconnects there would be no connection between the input and output components of an audio system. Although unterminated, bare-wire interconnects can be used, this type of connector does not fasten securely to the destination component and may not have a tight connection. Without a terminated connection, the wires cannot be tightened. The quality of the used terminated interconnects affects the quality of the sound put out by an audio system like a Hi-Fi setup.
When looking for a used terminated interconnect, it is important to research the types of interconnect cables available, what materials they are made from, the length of the cable, and the features and components of each type of used terminated interconnect available. One can find these connectors in shops that specialise in audio equipment. However, stocks may be limited, and they may not offer a range of used terminated interconnects. Audiophiles often find that eBay has larger selection of used terminated interconnects to choose from.
What Is a Terminated Interconnect?
Most cable, or interconnects, have terminations at their ends that allow them to complete the transmission path between two components. A terminated interconnect joins the input to the output components. For excellent sound, high-quality terminators are essential. These terminators should have a large surface area to ensure a good contact with the cable plug and component jack, as well as adequate contact pressure between the two. Good plugs have locking mechanisms or slits in the centre pin to allow one to tighten the plug around the component jack.
The term 'interconnect' generally refers to any type of wire other than speaker cables. The two types of wire look very similar, and the best way to tell them apart is to inspect the connectors. Interconnects have specialised connections depending upon the application. For instance, HDMI interconnects have flat, trapezoidal plugs, whilst RCA cables have rounded collars and centre pins. The two are not interchangeable.
Terminating an electrical signal is accomplished by crimping a terminator to the end of the interconnect wire or cable. Terminators are made to match the current in the interconnect and minimise signal reflections, which are parts of the signal that are reflected back along the interconnect rather than being sent on to the terminated ends.
It is optional whether or not one should terminate speaker wires. Bare wire can work as well as terminated wires, sometimes better, because the addition of a terminator can create more surface area that could fail over time. However, the absence of a terminator can also create secure connection issues.
The Geometry of the Terminated Interconnect
Interconnects have three main components: signal conductors, the dielectric, and terminations. Each of the individual elements is necessary to the geometry of the interconnect and can affect its sonic characteristics.
Conductors carry audio signal and are generally made from high-purity copper wiring. This type of copper wire is called 'six-nine' because it is 99.9999 percent pure. Some interconnects use silver-plated copper or even pure silver conductors. These are very expensive and a produce a characteristic sound.
Inside each interconnect are strands of metal wire. Different quality interconnects have different types of wire. Copper and gold have been used for many years because of their electrical conductivity, and resistance to erosion. However, the use of rhodium and silver in the manufacture of interconnects is increasing.
Rhodium is quite beautiful, and looks very much like silver. In terms of how good it performs as an electrical contact, rhodium has a very low electrical resistance and a low and stable contact resistance, and is very resistant to corrosion. Rhodium is the ideal metal for speaker spade terminals and banana plugs. Basically anywhere that air can interact with metal components is a good place to use rhodium.
Silver is a much better conductor than copper, and because of this it is often used for interconnects. There are pure silver interconnects and silver coated copper interconnects. Silver has good electrical conductivity, and in fact has the highest thermal conductivity of all metals, while at the same time has the lowest contact resistance. Pure silver interconnects for speaker wire, RCA, and BNC audio cables are very common. However, pure silver interconnects are very costly and because of this, silver coated copper interconnects are used more widely. Silver coated copper interconnects are quite expensive, although cheaper to make than pure silver interconnects because they contain less silver. Generally these interconnects are coaxial cable with a centre that is coated with silver.
Many audiophiles believe that silver has the ability to impart a smooth sound and that it provides a crystal clear quality to the audio, while others believe that it causes the sound to be harsh, brash, or too bright.
The insulating material surrounding conductors, and embedded between them, is called dielectric. This material provides much of the bulk of the interconnects, and has a big effect on how a cable conducts signals. Some of the types of dielectric materials include PVC, polyethylene, and polypropylene. Teflon is used in the higher-end cables.
The insulation coating the conductors can cause a non-uniform, dielectric medium around the conductors that stores energy from them in the form of charge. Like a battery, this dielectric material prevents the conductor from discharging when it should, resulting in a latent charge that can be released at inopportune moments. This is called 'dielectric absorption', and is generally more of an issue with less expensive interconnects that utilise PVC for insulation rather than Teflon.
Terminations allow interconnects to link one component to another in an audio setup. The most common type of terminators are solder-tinned wire ends, crimped, spade lugs, banana plugs, and two-pin DIN connectors. Different terminators can be used for each end of the interconnect, depending upon the type of connection jacks on the equipment at either end of the interconnect.
Minimising Capacitance and Skin-Effect
Some features of terminated interconnects provide distinct advantages to an audio system, however there are some aspects of those very same features that can be disadvantageous under certain circumstances.
The purpose of interconnects is to transfer analogue voltage between two components. The current is always very small because the load the interconnect can drive is usually between 10 and 100,000 ohms. This number reflects the input impedance, or the combination of the inductance and capacitance, of the component driven by the signal. There is no power transfer with intercepts at all. Capacitance is the ability of an object to store electricity. If the capacitance is very high, the resulting high frequencies begin to decrease because of the loading on the driver. An interconnect can contribute more to the overall capacitance than the receiving component, and because of this it is important to try and minimise the capacitance of the interconnect.
The capacitance of an interconnect is directly related to its length, geometry and insulation. The longer it is, the higher the capacitance. This is why interconnects that are shorter are better than interconnects that are longer. The standard lengths for interconnects are 1, 1.5, and 2 metres. Capacitance can be minimised as well, by spacing the conductors as far apart as possible and avoiding parallel placement.
Skin-effect is the flow of high-frequency current across the outer 'skin' of the conductors, while low-frequency current flows over the cross-section of the conductor. This results in a different impedance for low and high frequencies, lowering the high-frequency in relation to the low-frequency and resulting in a smearing effect to the music.
How to Buy a Used Terminated Interconnect on eBay
To begin your search for used terminated interconnects, you can enter keywords into the search bar at the top of any page on eBay. For instance, if you enter 'used terminated interconnects', the local search engine pull out all the current listings for audio cables and connectors. As such a generic search query will return thousands of listings, it is important to use the search filters to narrow down the search. You are able to sort the listings based on their condition, in this case used, the brand, the terminations, or connectors, and the cable's length. Remember, that to ensure the best sound quality, you should go for the shortest length of cable you can manage to connect the audio components.
When reading the item descriptions for the used terminated interconnects listed for sale, make sure to examine the specifics carefully. You should also take note of the condition the cables are in, especially the terminations. Look at the photos in the item listings. You should look for any signs of corrosion or other indicators of wear and tear or damage to the insulation and the terminations. If you have any questions for the seller, you can contact the seller by going into the seller's profile and clicking on the contact link.
Interconnects are cables or wires that connect two pieces of audio equipment, and the terminators are the ends which connect to the jacks on components to either side of of the interconnect. Interconnects are important components because they conduct audio signals from the pre-amplifier to the amplifier. Terminated interconnects create a connection between the input and output components of the system. Good cable interconnects are essential to an audio system's overall sound quality. The choice of interconnects comes down to cable geometry.
The buyer must consider the conductors and the terminators and the materials they are made from, as well as the dielectric, or cable insulation. There is also the length to consider. A buyer should opt for the shortest length of cable required to connect the audio components. While quality terminated interconnects cannot make a system of substandard and incompatible components sound better, these connectors can be used to tweak a good sound system so that it performs better.