Patent ID: 6937093
Filing Date: 2005-08-30
Classification: H03F

Abstract:
1. An amplifier, comprising: a pair of cathode-coupled pentode vacuum tubes, a first pentode of the pair having a control grid configured to receive an input signal, and a second pentode of the pair having a control grid configured to be coupled to an input reference signal; and a cascaded voltage regulator having a first stage configured to generate a plate reference voltage for providing voltage to a plate of each pentode, and a second stage configured to generate a screen reference voltage based on the plate reference voltage for providing voltage to a screen grid of each pentode, wherein the amplifier can be configured to generate a pair of complementary output signals at the plates of the pentodes proportional to the input signal; a pair of screen grid resistors, each screen grid resistor having a first terminal connected to the screen reference voltage and a second terminal connected to the screen grid of a respective one of the pentode.