Audio amplifier

Audio frequency power amplifier with improved circuit topology

Direct box employing hybrid vacuum tube and solid state circuitr

Enhanced vacuum tube power amplifier

Field emitting drain field effect transistor

High-efficiency low distortion parallel amplifier

Hybrid audio amplifier

Hybrid solid state/vacuum tube audio amplifier

Hybrid thermionic valve and solid state audio amplifier

Output signal converter for ampliciation or attenuation of...

Output signal converter for tube amplifiers

Power amplifier with switchable voicing elements

Reflected plate amplifier

Stabilized microwave power amplifier system

Tube input JFET output (TIJO) zero feedback audio amplifier

Vacuum tube and MOSFET transimpedance amplifier

Vacuum tube replacement device, circuit and system

Wideband dual amplifier circuits