Abstract: A filter network adapted to be placed in parallel with a power supply which acts like a short circuit at a specified frequency range above 80 kHz. The filter 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: A critically damped capacitor comprising a capacitance C having in series therewith a parasitic inductance L.sub.S, a parasitic resistance R.sub.S and an additional resistance R.sub.A in series with the plates of the capacitor. The value of R.sub.A is chosen such that ##EQU1## The additional resistance R.sub.A 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 R.sub.A 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.