Abstract: A buffer amplifier with unity voltage gain, high input impedance, high speed, high current gain, high output power and low offset includes three stages and a DC servo circuit. The first stage of the buffer amplifier contains complementary N-channel and P-channel MOSFET source followers that provide high input impedance to buffer the input signal source. A feedback DC servo signal is provided to correct the subsequent stages so as to maintain the output at virtual DC ground level. The second stage is a driver stage that also contains complementary N-channel and P-channel MOSFET source followers to provide sufficient current to drive the output stage. The last stage is an output stage that contains at least one pair of complementary power MOSFETs or BJTs to deliver high currents to a load.

Abstract: A buffer amplifier with unity voltage gain, high input impedance, high speed, high current gain, high output power and low offset includes three stages and a DC servo circuit. The first stage of the buffer amplifier contains complementary N-channel and P-channel MOSFET source followers that provide high input impedance to buffer the input signal source. A feedback DC servo signal is provided to correct the subsequent stages so as to maintain the output at virtual DC ground level. The second stage is a driver stage that also contains complementary N-channel and P-channel MOSFET source followers to provide sufficient current to drive the output stage. The last stage is an output stage that contains at least one pair of complementary power MOSFETs or BJTs to deliver high currents to a load.

Abstract: A single stage differential amplifier is disclosed as comprising a pair of vacuum tube triodes for amplifying two input signals and generating two output signals. The differential amplifier has DC self-biasing ability and grid-to-cathode over-voltage protection for directly coupling from the outputs of another differential amplifier. By possessing these unique features, this differential amplifier becomes an important building block in forming a balanced amplifier by cascading multi differential amplifiers in a directly coupled fashion.

Abstract: A single stage differential amplifier is disclosed as comprising a pair of vacuum tube triodes for amplifying two input signals and generating two output signals. The differential amplifier has DC self-biasing ability and grid-to-cathode over-voltage protection for directly coupling from the outputs of another differential amplifier. By possessing these unique features, this differential amplifier becomes an important building block in forming a balanced amplifier by cascading multi differential amplifiers in a directly coupled fashion.

Abstract: A balanced voltage amplifier is disclosed as comprising a single stage containing three pairs of vacuum tube triodes configured to amplify two input signals (+INPUT, ?INPUT) and to generate two output signals (+OUTPUT, ?OUTPUT). The balanced voltage amplifier offers high voltage gain, wide bandwidth and low output impedance. Local feedback may be applied between the outputs and the second pair of triodes. Overall feedback may be applied between the outputs and the first pair of triodes. If local or overall feedback is used, it will further broaden the bandwidth, lower the output impedance and improve the overall balancing.

Abstract: A balanced voltage amplifier is disclosed as comprising a single stage containing three pairs of vacuum tube triodes configured to amplify two input signals (+INPUT, ?INPUT) and to generate two output signals (+OUTPUT, ?OUTPUT). The balanced voltage amplifier offers high voltage gain, wide bandwidth and low output impedance. Local feedback may be applied between the outputs and the second pair of triodes. Overall feedback may be applied between the outputs and the first pair of triodes. If local or overall feedback is used, it will further broaden the bandwidth, lower the output impedance and improve the overall balancing.

Abstract: A balanced amplifier is disclosed as comprising an input stage connected with a second stage, in which the input stage outputs signals to the second stage, and the first stage includes a first differential amplifier for receiving balanced input signals and is provided with two pairs of feedback loops, at least one of the pair of feedback loops for feedbacking part of signals outputted by the second stage to the first differential amplifier, and the second stage includes a second differential amplifier for amplifying signals received from the first stage and for maintaining the balanced signals.