Variable capacitance audio cable

• US 8,246,384 B1
• Filed: 07/24/2009
• Issued: 08/21/2012
• Est. Priority Date: 07/25/2008
• Status: Active Grant

• Current Assignee: Henry B. Wallace
• Original Assignee: Henry B. Wallace
• Inventors: Wallace, Henry B.
• Primary Examiner(s): Gilman, Alexander
• Application Number:
  US12/460,776
• Time in Patent Office: 1,124 Days
• Field of Search: 439/620.01, 324/690, 324/688, 174/386, 174/102, 330/254, 330/53, 330/185, 381/61, 381/77
• US Class Current: 439/620.01
• CPC Class Codes: H01R 2103/00 Two poles
• CPC Class Codes: H01R 2105/00 Three poles
• CPC Class Codes: H01R 24/562 Cables with two screens
• CPC Class Codes: H01R 24/58 Contacts spaced along longitudinal axis of engagement

Abstract

The variable capacitance audio cable allows adjustment of the frequency response of the system in which the cable is used by varying the cable capacitance electronically. This permits musical performers using the cable to tailor the audio response to suit their performance and style.

Claims

1. An audio cable means for use with musical instruments employing passive pickups, which comprises:

(a) a first conductor having a first end and a second end; and

(b) a second shield conductor, having a first end and a second end, disposed tubularly around said first conductor, separated by a first dielectric therefrom; and

(c) a third conductor, having a first end and a second end, situated external to said second shield conductor, separated by a second dielectric therefrom; and

(d) an overall insulating layer; and

(e) a first connector having at least a signal terminal and a shield terminal, with said first end of said first conductor connected to said signal terminal, and with said first end of said third conductor connected to said shield terminal; and

(f) a second connector having at least a signal terminal and a shield terminal, with said second end of said first conductor connected to said signal terminal, and with said second end of said third conductor connected to said shield terminal; and

(g) a manually controlled electronic amplifier whose input is connected to said first conductor and whose output is connected to said second shield conductor, said electronic amplifier having an overall variable gain from zero to a maximum gain, said maximum gain being less than unity at all frequencies, said electronic amplifier having a transfer function selected from the group consisting of notch filter, allpass filter, bandpass filter, lowpass filter, highpass filter, and nonuniform frequency response filter;

whereby said variation in gain of said electronic amplifier changes the interelectrode capacitance between said first conductor and said third conductor of said audio cable means from a first capacitance at the highest said overall variable gain to a second capacitance at a said overall variable gain of zero, said first capacitance measured at any single frequency being inversely proportional to the specific gain of said electronic amplifier at said single frequency, said second capacitance being the characteristic said interelectrode capacitance of said audio cable means.

2. The audio cable means of claim 1 wherein the manual control means is provided to control said overall variable gain of said electronic amplifier, whereby said manual control means is actuable by the musician who is using said audio cable, to produce pleasing tonalities.

3. The audio cable means of claim 1 wherein the manual control means is provided to select said transfer function of said electronic amplifier, whereby said manual control means is actuable by the musician who is using said audio cable, to produce pleasing tonalities.

4. The audio cable means of claim 1 wherein said transfer function of said electronic amplifier is selected from said group during manufacture of said audio cable means.

5. The audio cable means of claim 1 wherein said first dielectric has disposed on its outer surface a semi-conductive layer.

6. A method of varying the interelectrode capacitance of an audio cable, said audio cable for use with musical instruments employing passive pickups, which comprises:

(a) providing an audio cable means comprised of a first conductor, a second shield conductor disposed around said first conductor and separated by a first dielectric therefrom, a third conductor situated external to said second shield conductor and separated by a second dielectric therefrom, and an overall insulating layer; and

(b) providing a manually controlled electronic amplifier whose input is connected to said first conductor and whose output is connected to said second shield conductor, said electronic amplifier having an overall variable gain from zero to a maximum gain, said maximum gain being less than unity at all frequencies, and having a transfer function selected from the group consisting of notch filter, allpass filter, bandpass filter, lowpass filter, highpass filter, and nonuniform frequency response filter;

whereby said variation in gain of said electronic amplifier changes the interelectrode capacitance between said first conductor and said third conductor of said audio cable from a first capacitance at the highest said overall variable gain to a second capacitance at a said overall variable gain of zero, said first capacitance measured at any single frequency being inversely proportional to the specific gain of said electronic amplifier at said single frequency, said second capacitance being the characteristic said interelectrode capacitance of said audio cable.

7. The method of claim 6 wherein the method of variation of said overall variable gain of said electronic amplifier is actuation of the manual control, whereby said manual control is actuable by the musician who is using said audio cable to produce pleasing tonalities.

8. The method of claim 6 wherein the method of selection of said transfer function of said electronic amplifier is actuation of the manual control, whereby said manual control is actuable by the musician who is using said audio cable to produce pleasing tonalities.

9. The method of claim 6 wherein the method of selection of said transfer function of said electronic amplifier is selection of a transfer function during manufacture of said audio cable.