WO1998028756A1

WO1998028756A1 - Cables for high-fidelity audio systems

Info

Publication number: WO1998028756A1
Application number: PCT/EP1997/007280
Authority: WO
Inventors: Marco Verdi; Lionello Verdi
Original assignee: Marco Verdi; Lionello Verdi
Priority date: 1996-12-23
Filing date: 1997-12-19
Publication date: 1998-07-02
Also published as: ITMI962717A1

Abstract

Improved cables for high-fidelity audio systems are disclosed. The disclosed cables find an application both for transferring the signal to the separate components of an audio chain (source - preamplifier - final amplifier), and for the 'power' connection of the final amplifier with the transducers (loudspeakers), as well as the connection with the supply mains, in any case resulting in excellent audio performances with respect to 'transparency' and unaffectedness of timbre.

Description

"CABLES FOR HIGH-FIDELITY AUDIO SYSTEMS"

The present invention relates to cables for high-fidelity audio systems, particularly for the signal connection of the various components of a high-fidelity audio chain, for the power connection of the final amplifier with the transducers, and also for the connection with the supply mains.

The stereophonic systems defined as "high-fidelity" are comprised of the association of various audio apparatuses, each absolving a well defined task in playing a musical piece: there are the "sources", dealing with the "reading" of the support on which the piece was pre-recorded (gramophone, CD-player, tape-recorder, etc.) and the transformation thereof in an electric signal; the "preamplifier", mainly used for switching the source to be played and adjusting the listening volume; the "final amplifier", amplifying the electric signal from the preamplifier, thus providing the necessary power to drive the transducers, namely the loudspeakers. The connection among the various components is carried out by means of cables, which therefore should have good audio performances, namely should bring about minimal damping, should have an excellent signal/noise ratio, and should have an excellent linearity in order not to alter the original signal.

Among the prior art proposals, cables with a copper or silver, or even gold wire can be found. The known cables of the type mentioned at the beginning normally use wires in a braided multi-wire configuration, individually lined without clearance in internal sheaths, in turn sheathed without clearance in external hoses. The known cables with copper wire are, however, less than optimal from the standpoint of the performances offered, while the cables in more valuable materials (silver and special alloys) have very high costs, not allowing for a widespread use thereof.

It is also known that the mains voltage has its own noise, adversely affecting the system audio performances. To obviate this problem, traditionally "pure" supplies (battery operated) or mains stabilizer filters and mains conditioners are used, however with extremely high costs and/or the hindrance of further devices inserted into the high-fidelity system or between it and the supply mains.

Object of the present invention is to provide a cable for audio systems, usable for any type of connection (signal connection of sources - preamplifier - final amplifier, power connection of final amplifier with transducers, and connection with the supply mains), which provides the system with excellent audio performances with respect to transparency (excellent frequency response), as well as damping and unaffectedness of timbre.

This object is achieved by the high-fidelity audio system cable having the characteristics recited in independent claim 1. Further advantageous characteristics of said high-fidelity audio system cable are indicated in the dependent claims.

The characteristics, objects, and advantages of the present invention will be more evident from the following description and the annexed drawings, relating to non-limiting embodiments. The various Figures show:

Figure 1 is a first high-fidelity audio system cable according to the present invention;

Figure 2 is a second high-fidelity audio system cable according to the present invention; and Figure 3 is a third high-fidelity audio system cable according to the present invention.

In Figure 1 a first high-fidelity audio systems cable 10 according to the present invention is diagrammatically depicted, being particularly suitable for the "signal" connection of the various components of a high-fidelity audio chain, namely the connection of source, preamplifier, and final amplifier. The cable according to the invention has, internally, two wires 12, 12' comprised of a core 18, 18', respectively on which a relatively great pitch spiral 20, 20' is wound.

These wires 12, 12' are commercially available, however intended for a completely different use, namely as small tying cables. In the commercial form, core 18, 18', and spiral 20, 20' are made of low carbon content galvanized iron. However, it should be pointed out that in cable 10 according to the invention, core 18, 18' may also be made of brass, copper, or melts and/or alloys thereof, and the spiral 20, 20' also can be chosen in any of the cited materials, not necessarily the same as that of core 18, 18'.

With respect to sizes, the diameter of core 18, 18' may be chosen as about 0.5 mm, and that of spiral 20, 20' of about 0.3 mm.

Wires 12, 12' run inside two heatshrinkable sheaths 14, 14', respectively, with insulating function. Other insulators that can be used are varnish, varnish and cotton, varnish and heatshrinkable sheath. Finally, sheaths 14, 14' are sheathed without clearance by a hose 16 made of a plastic material, preferably PTFE (Teflon^® E.I. DuPont De Nemours, USA) or Nylon 11 commercially known as Rilsan PA 11^® (Atochem SA, France). Both the sheath 14, 14', and the hose 16 are normally commercially available, however intended to extremely different uses, such as convey of compressed air, oils under pressure, and so on.

In Figure 2 a second embodiment of a cable 30 according to the invention is depicted. Cable 30 is comprised of two wires 32, 32' completely equal to wires 12, 12' of the first cable 10 shown in Figure 1, namely comprised of two cores 38, 38' wound by a spiral 40, 40', respectively. Wires 32, 32' run inside two sheaths 34, 34', which are longitudinally joined as in a standard electric rip cord, and are not further sheathed. In this case, sheaths 34, 34' are made of Teflon or Rilsan PAH, and a further insulation may be present, in the materials cited with reference to the embodiment of Fig. 1, namely varnish, varnish and cotton, varnish and heatshrinkable sheath. Cable 30 of the present embodiment is also particularly suitable for "signal" connection. The absence of an external sheath, though worsening the cable from an aesthetically-functional standpoint, allows for a reduction in the manufacturing costs.

In Figure 3 an audio system cable 50 according to the invention is diagrammatically depicted, particularly suitable for the "power" connection of the final amplifier with the transducers. Cable 50 is constructed with various, particularly six, wires 52a, 52b, 52c; 52'a, 52'b, 52'c, grouped in two groups, particularly three wires each, enclosed in sheaths 54, 54', respectively, of Teflon or Rilsan PAH, and other similar plastic or gummy materials. The three wires 52a, 52b, 52c; 52'a, 52'b, 52'c of each group are not joined to each other apart from at their ends. Wires 52a, 52b, 52c; 52'a, 52'b, 52'c, and sheaths 54, 54' are made of materials similar to those of the other embodiments, and analogous features apply as to the external coating and wire insulation. Surprisingly, it resulted that the disclosed cables, and particularly cable 50 according to the third embodiment, contribute to excellent audio performances also when used for the connection with the supply mains. In this case, of course a third wire for ground connection may be provided.

With cables 10, 30, 50 according to the invention, excellent audio performances are obtained at a very limited cost. As far as the purely "musical" performances are concerned, it must be specified that, due to the variables at stake being related to a very complex assembly as the human ear, still no objective measures exist capable of estimating the quality of any apparatus intended to sound playing: actually, subjective evaluations take place, carried out by people skilled in the art, having listening experience. These cables, subjected to such subjective tests, obtained the consent of various experts in the art: relevant transparency (namely ability of the cable not to affect the playing, thereby allowing to create anew the original sound, as was live recorded) and pleasantness. All that related to a very limited cost with respect to prior art cables.

Finally it should be noted that the cables depicted and disclosed are merely exemplary of the innumerable combinations possible applying the principle of the invention, which, as will be evident for those skilled in the art, consists in applying the special described wires comprised of core and spiral. Particularly, while always symmetrical cables were described, excellent results are also obtained with asymmetric cables, for example by inserting in one Teflon or Rilsan PAH sheath a wire (as defined hereinbefore) insulated by cotton or heatshrinkable sheath, and a bare wire.

Claims

1. A high-fidelity audio system cable (10, 30, 50) comprising two groups of at least one wire each (12, 12'; 32, 32'; 52a, 52b, 52c; 52'a, 52'b, 52'c), extending in at least one sheath (16; 34, 34'; 54, 54'), characterized in that each of said wires (12, 12'; 32, 32'; 52a, 52b, 52c; 52'a, 52'b, 52'c) is comprised of a tubular core (18, 18'; 38, 38'; 58a, 58b, 58c; 58'a, 58'b, 58'c) on which a relatively great pitch spiral (20, 20'; 40, 40'; 60a, 60b, 60c; 60'a, 60'b, 60'c) is wound.

2. The cable (10, 20, 30) according to claim 1, characterized in that said cores (18, 18'; 38, 38'; 58a, 58b, 58c; 58'a, 58'b, 58'c) of said wires (12, 12'; 32, 32'; 52a, 52b, 52c; 52'a, 52'b, 52'c) are comprised of a material chosen from the group comprising low carbon content galvanized iron, brass and copper, and melts and/or alloys thereof, and that said spirals (20, 20'; 40, 40'; 60a, 60b, 60c; 60'a, 60'b, 60'c) of said wires (12, 12'; 32, 32'; 52a, 52b, 52c; 52'a, 52'b, 52'c) are comprised of a material chosen from the group comprising low carbon content galvanized iron, brass and copper, and melts and/or alloys thereof.

3. The cable (10, 30, 50) according to either of claims 1 or 2, characterized in that said sheaths (16; 34, 34'; 54, 54') are made of a plastic material.

4. The cable (10, 30, 50) according to claim 3, characterized in that said sheaths (16; 34, 34'; 54, 54') are made of PTFE or Nylon 11. 5. The cable (10, 20, 30) according to any of claims 1 to 4, characterized in that said cores (18, 18'; 38, 38'; 58a, 58b, 58c; 58'a, 58'b, 58'c) have a diameter of about 0.

5 mm and said spirals (20, 20'; 40, 40'; 60a, 60b, 60c; 60'a, 60'b, 60'c) have a diameter of about 0.3 mm.

6. The cable (10, 30, 50) according to any of the preceding claims, characterized in that at least one of said wire groups (12, 12'; 32, 32'; 52a, 52b, 52c; 52'a, 52'b, 52'c) is lined by an insulation (14, 14') chosen from the group comprised of varnish, varnish and cotton, heatshrinkable sheath, varnish and heatshrinkable sheath.

7. The cable (50) according to any of the preceding claims, particularly for the "power" connection of final amplifier with the transducers or loudspeakers, or for the connection with the supply mains, characterized in that each group of wires (12, 12'; 32, 32'; 52a, 52b, 52c; 52'a, 52'b, 52'c) comprises three wires (12, 12'; 32, 32'; 52a, 52b, 52c; 52'a, 52'b, 52'c), joined at their ends only.

8. The cable (10, 30, 50) according to any of the preceding claims, particularly for the connection with the supply mains, characterized by a further wire for ground connection.

9. The cable (10, 30, 50) according to any of the preceding claims, characterized by an external aesthetic fabric coating.