MIT Cables Patents - More than Any Other Cable Manufacturer

 

"Audio signal cable"  US Patent 4,538,023
An audio cable in which a plurality of outer conductors surround one or more inner conductors. The outer conductors provide a path for the relatively high frequency components of the signal and the inner conductors provide a path for the relatively low frequency components of the signal. The length of each outer conductor is greater than the length of the inner conductors and the outer conductors are wound around the inner conductors so that the frequency components of the signal arrive at the end of the end of the cable at the same time.

"High current demand cable"  US Patent 4,718,100
Cabling (10) is provided for interconnecting amplifier (12) having a positive side (14) and a return side (16) to a load (18) having a positive side (20) and a return side (22). The cabling comprises a first open circuited conductor (24) having a first end (26) connected to a selected one of the amplifier positive side (14) and the amplifier return side (16) and having a second end (28) extending towards and terminating free from connection to the load (18). A second open circuited conductor (30) is provided which has a first end (32) connected to a respective one of the load positive side (20) and the load return side (22), said respective one being of a different polarity than the polarity of the selected one of the amplifier positive side (14) and amplifier return side (16) to which the first open circuited conductor (24) is connected and having a second end (34) extending towards and terminating free from connection to the amplifier (12). A first amplifier-load connecting structure (38) serves for electrically connecting the amplifier positive side (14) to the load positive side (20), the first connecting structure (38) being wound about at least a majority of the length of a selected one of the first and second open circuited conductors (24,30). A second amplifier-load connecting structure (40) serves for electrically connecting the amplifier return side (16) to the load return side (22), the second connecting structure (40) being wound about at least a majority of the length of a selected other of the first and second open circuited conductors (24,30). Improved sound results from use of such cabling.

"Audio frequency cable with reduced high frequency components"  US Patent 4,994,686
Audio cabling includes a first conductor in conductive communication with the positive side of the source or of the load. It extends towards but terminates free of the load if it is connected to the source and free of the source if it is connected to the load. A second conductor has a first end in conductive communication with the negative side of the source or of the load. If it is connected to the source negative side it has a second end which extends towards but terminates free of the load. If it is connected to the load negative side it has a second end which extends toward but terminates free of the source. The conductors are separated from one another by a non-conductor. They are sufficiently long whereby they are in adjacent side by side relation at least along portions thereof. High frequency noise which can affect the ear's perception of audio frequency signals is reduced as are low frequency resonance effects.

"Audio signal transmission system with noise suppression network"  US Patent 4,954,787
In an audio signal transmission system comprising an interface circuit is connected across the output terminals of an audio signal source or across the input terminals of an audio signal transmission cable coupled to the source. The interface circuit comprises either a discrete capacitance or a distributed capacitance in series with a discrete resistor. The value of the capacitance and the resistance in the interface circuit is chosen such that the time constant of the cable with the interface circuit produces in response to noise a signal having a frequency which is above the audio frequency spectrum but within the passband of the amplifier to which it is coupled.

"Method & apparatus for reducing attenuation & phase shift"  US Patent 5,123,052
In an audio signal transmission system having a source of audio signals and a load coupled thereto by means of a first and second transmission line, a discrete capacitor is coupled in parallel with one or both of the transmission lines. The magnitude of the capacitor is as large as stable operation of the amplifier to which it is connected will permit.

"Audio signal transmission line with low-pass filter (series or parallel inductance)"  US Patent 5,142,252
An audio signal transmission line comprising an additional inductance inserted in series with the line and/or coupled in parallel therewith near the load end of the line for providing a low pass filter which overcomes parasitic and dielectric capacitance of the line so as to reduce audio frequency noise generated in the line by low level and low frequency audio signals. The magnitude of the inductance used may vary widely, e.g. from 20 microhenries to 1 millihenry, depending on the length of the line and the space available.

"Critically damped capacitor & method of making same (Multicap)"  US Patent 5,144,522
A critically damped capacitor comprising a capacitance C having in series therewith a parasitic inductance LS, a parasitic resistance RS and an additional resistance RA in series with the plates of the capacitor. The value of RA is chosen such that ##EQU1## The additional resistance RA in one embodiment is provided by a layer of conductive epoxy which is attached or added to one or both of the end plates of the capacitor. Electrical leads are coupled to the end plate having the epoxy by being embedded in the epoxy. If epoxy is not used on an end plate, the lead is coupled to the end plate in a conventional manner. In another embodiment the additional resistance RA is provided by a discrete resistor which is welded, soldered or otherwise attached to one or both of the end plates. If only one resistor is used, one lead of the capacitor is coupled to its end plate in a conventional manner and the second lead is coupled to the free end of the resistor. In one embodiment, the resistor is enclosed and the ends of the capacitor sealed by a non-electrically conductive epoxy. In another embodiment, the capacitor and resistor are enclosed within a container filled with non-conductive epoxy and the leads of the capacitor extend externally therefrom in a conventional manner so as to form an integrated capacitive element or device.

"Filter & power compensation network"  US Patent 5,227,962
A filter network adapted to be placed in parallel with a power supply which provides a high impedance to the 60 Hz utility frequency but acts like a short circuit to all higher frequencies. The network comprises a plurality of parallel circuits, each of which comprise a capacitor, an inductor and a resistor in series with a second resistor coupled in parallel with the inductor. Signal levels above 60 Hz in a prototype circuit using seven such parallel circuits with a parallel capacitor coupled thereto shows that above 60 Hz the signal from the power supply is attenuated by 25-30 dB at 1 KHz and that the impedance is substantially resistive beyond 1 KHz. To maximize the power factor of the circuit comprising the network and consequently the dynamic range of audio equipment coupled thereto, the magnitude of the total capacitance of the network is chosen to be as close as possible to the magnitude of the input inductance of the audio equipment. Switches are provided for selectively adjusting the number of parallel circuits in the network to change its frequency response as well as to accommodate loads having different input inductive reactance at 60 Hz.

"AC power line filter"  US Patent 5,260,862
A filter network adapted to be placed in parallel with a power supply which provides a high impedance to the 60 Hz utility frequency but acts like a short circuit to all higher frequencies. The network comprises a plurality of parallel circuits, each of which comprise a capacitor, an inductor and a resistor in series with a second resistor coupled in parallel with the inductor. Signal levels above 60 Hz in a prototype circuit using seven such parallel circuits with a parallel capacitor coupled thereto shows that above 60 Hz the signal from the power supply is attenuated by 25-30 dB at 1 KHz and that the impedance is substantially resistive beyond 1 KHz.

"Digital interface cable"  US Patent 5,412,356
A single-ended digital interface cable and a balanced digital interface cable having a source end and a load end for propagating audio frequency signals in a digital format is disclosed. Each of the cables comprises a fixed capacitor or a capacitor and switch network which is coupled at or near the load end of the cables for providing a fixed bandwidth or for use in selectively controlling the bandwidth of the cables and a series resistance at each end thereof to dampen ringing.

"Iconn® Universal Connector System"  US Patent 5,791,919
An electrical connector is set forth which is suitable for connection to a conductor which includes a connector member suitable for attachment, for example by soldering or by a crimping device, to a conductor, such as a cable. The electrical connector also includes a terminal pin connectable to an electrical receptor or terminal, for example in a part of an audio system. The connector member also includes a threaded part onto which any one of several types of alternative connector units may be mounted to enable use of the same conductor and its attached connector with different types of audio system receptors or terminals. A right-angle adapter may also be used to join the electrical connector to one of the alternative connector units.

"Balanced power amplification system"  US Patent 5,914,636
A configuration of audio system components, utilizing standard amplifier components, wherein the audio system remains balanced through the speaker input terminals. For each channel of the system, a preamplifier produces a balanced output signal. Two power amplifiers or similar devices are conventionally configured to accept positive and negative input signals. The negative signal output of the preamplifier is connected to the positive input terminal of one of the power amplifiers, and the positive output signal of the preamplifier is connected to the positive input terminal of the other power amplifier. The negative and ground input terminals of both power amplifiers are connected to system ground. The connections between the preamplifiers and the amplifiers may be effected by a unique cable designed for this purpose. The positive output terminal of one of the power amplifier is connected to positive input terminal of the speaker, while the positive-output terminal of the other power amplifier is connected to the negative input terminal of the speaker. The negative output terminals of each power amplifier "floats", unconnected externally to the speakers.

"Audio transmission line with Energy Storage Network (Input Terminator)"  US Patent 5,956,410
An audio signal transmission line including capacitive and/or inductive networks connected in series or parallel with an audio transmission cable providing for increased storage of electrical energy, and thereby overcoming energy storage problems associated with previous audio signal transmission systems which create unwanted pre-emphasis of audio signals at certain frequencies.

"Audio signal cable with passive network"  US Patent 6,658,119
A network for altering the audio output of a system which comprises at least one series RC or RLC circuit coupled between the positive and ground conductor of a cable that is suitable for connecting an electrical musical instrument, or similar source, to an amplifier or other load. The components of the RC or RLC circuit are selected by determining the frequency at which the positive conductor's natural phase angle is 45°. Each of the RC or RLC circuits is selected to have a phase angle of -45° at a frequency equal to or different from the frequency at which the positive conductor has a phase angle of 45° depending upon the audio effect desired. In addition, the component values of the circuits are selected such that the measured impedance of the network at all frequencies in a predetermined frequency range is equal to or greater than 0.20 MO, and the overall combined capacitance of the cable and the capacitance and/or inductance of the network does not cause the effect of audible “roll-off” in the system.

"Audio signal cable with passive network"  US Patent 7,242,780
A network for altering the audio output of a system which comprises at least one series RC or RLC circuit coupled between the positive and ground conductor of a cable that is suitable for connecting an electrical musical instrument, or similar source, to an amplifier or other load. The components of the RC or RLC circuit are selected by determining the frequency at which the positive conductor's natural phase angle is 45°. Each of the RC or RLC circuits is selected to have a phase angle of -45° at a frequency equal to or different from the frequency at which the positive conductor has a phase angle of 45° depending upon the audio effect desired. In addition, the component values of the circuits are selected such that the measured impedance of the network at all frequencies in a predetermined frequency range is equal to or greater than 0.20 MO, and the overall combined capacitance of the cable and the capacitance and/or inductance of the network does not cause the effect...

"Electrical cable"  US Patent D314,551

"Electrical connector"  US Patent D317,292

"Elongated audio connector"  US Patent D434,003

"Enclosure for a consumer electronic device"  US Patent D436,935

"Enclosure for a speaker cable connector"  US Patent D446,778