Differential amplifier

Claim 1

AN AMPLIFIER COMPRISING FIRST, SECOND, THIRD AND FOURTH AMPLIFYING DEVICES EACH COMPRISING A CONTROL ELECTRODE, A COMMON ELECTRODE AND AN OUTPUT ELECTRODE, FIRST, SECOND, THIRD AND FOURTH LOAD IMPEDANCES FOR SAID FIRST, SECOND, THIRD AND FOURTH AMPLIFYING DEVICES RESPECTIVELY; A PAIR OF SOURCES OF LOAD CURRENT, MEANS CONNECTING A DIFFERENT ONE OF SAID SOURCES BETWEEN SAID FIRST AND SAID SECOND AMPLIFYING DEVICES AND THEIR ASSOCIATED LOAD IMPEDANCES, A COMMON ELECTRODE IMPEDANCE, MEANS CONNECTING SAID COMMON ELECTRODES OF SAID FIRST AND SECOND AMPLIFYING DEVICES THROUGH SAID COMMON ELECTRODE IMPEDANCE TO A NEGATIVE TERMINAL OF A SOURCE OF POTENTIAL HAVING A POSITIVE TERMINAL CONNECTED TO A POINT OF REFERENCE POTENTIAL, MEANS CONNECTING AN END OF SAID FIRST AND SECOND LOAD IMPEDANCES REMOTE FROM SAID LOAD CURRENT SOURCE TO ONE END OF SAID SOURCE OF POTENTIAL, SAID CONTROL ELECTRODES OF SAID THIRD AND FOURTH AMPLIFYING DEVICES BEING CONNECTED TO SAID FIRST AND SECOND LOAD IMPEDANCES, RESPECTIVELY, MEANS FOR BIASING SAID COMMON ELECTRODES OF SAID THIRD AND FOURTH AMPLIFYING DEVICES AT AN OPERATING POTENTIAL WITH RESPECT TO THEIR ASSOCIATED CONTROL ELECTRODES AND MEANS FOR CONNECTING SAID OUTPUT ELECTRODES OF SAID THIRD AND FOURTH AMPLIFYING DEVICES THROUGH AT LEAST THEIR ASSOCIATED LOAD IMPEDANCES TO THE POINT OF REFERENCE POTENTIAL, SAID SOURCE OF POTENTIAL PROVIDING A VOLTAGE OF SUFFICIENT MAGNITUDE TO RENDER SAID THIRD AND FOURTH AMPLIFYING DEVICES CONDUCTIVE, AND MEANS FOR COUPLING AN INPUT SIGNAL TO SAID CONTROL ELECTRODES OF SAID FIRST AND SECOND AMPLIFYING DEVICES.