Abstract: Apparatus and associated methods relate to generating isolated DC power using a Faraday shielded transformer coupled with an AC/DC power converter. First and second Faraday shields are configured to attenuate capacitive coupling between primary and secondary windings of the Faraday shielded transformer. The first Faraday shield is conductively coupled to a first DC node of the AC/DC power converter. The second Faraday shield is conductively coupled to a second DC node of the AC/DC power converter. In some embodiments, the first and second Faraday shields are associated with the primary and secondary windings, respectively, of the transformer. In some embodiments, two such DC power sources can be used to provide operating power for a circlotron amplifier.

Abstract: Apparatus and associated methods relating to the amplification of an audio signal. In particular, such application is performed by using an audio to pulse train converter configured to convert an analog audio signal to a complementary train of pulses having a duty cycle indicative of the level of the analog audio signal. The audio to pulse train converter can be a class-D amplifier, a sigma-delta amplifier, self-oscillating amplifier, or any other audio amplifier that is configured to provide complementary pulse trains each having a duty cycle that is representative of the input audio signal. The complementary pulse trains are directed to a circlotron that is configured to provide an amplified version of the audio signal at two output nodes. The amplifier circuit may further include one or more low pass filters and/or output reference resistors. Two similar circuits can be configured together to provide stereo audio amplification.

Abstract: Apparatus and associated methods relating to the amplification of an audio signal. In particular, such application is performed by using an audio to pulse train converter configured to convert an analog audio signal to a complementary train of pulses having a duty cycle indicative of the level of the analog audio signal. The audio to pulse train converter can be a class-D amplifier, a sigma-delta amplifier, self-oscillating amplifier, or any other audio amplifier that is configured to provide complementary pulse trains each having a duty cycle that is representative of the input audio signal. The complementary pulse trains are directed to a circlotron that is configured to provide an amplified version of the audio signal at two output nodes. The amplifier circuit may further include one or more low pass filters and/or output reference resistors. Two similar circuits can be configured together to provide stereo audio amplification.

Abstract: The present invention is a circuit for use as a preamplifier or amplifier. The circuit has first and second input terminals that are configured to receive first and second balanced input signals. The circuit also includes first and second active devices that control output signals. Each of the active devices have a source, a control, and an output. In one embodiment, the control of the first active device is coupled to the first input terminal. The control of the second active device is coupled to the second input terminal. The circuit further includes first and second output terminals at which output signals are provided. The first and second output terminals are coupled to the first and second active devices. The circuit includes an coupler that couples a floating power supply to the first and second output terminals, and to the first and second active devices.

Abstract: A push-pull power amplifier includes a pair of input terminals, a pair of output terminals, a pair of matched output tubes having cathode, plate, and grid terminals, and a pair of output power supplies, all of which are connected to form a bridge circuit. A floating bias supply is coupled between the grid and plate of both output tubes. A first feedback resistor couples the floating bias supply to the cathode of the first output tube. A second feedback resistor couples the floating bias supply to the cathode of the second output tube. The floating bias supply and feedback resistors provide degenerative feedback without affecting power gain.