Balanced low impedance differential input line preamplifier

A balanced low impedance differential input line preamplifier having low input impedance and good common mode rejection comprising:

• a first common base input stage including a first high gain transistor having its emitter connected to directly receive a first input signal applied to said balanced low impedance differential input line preamplifier;
• a second common base stage including a second high gain transistor having its emitter connected to directly receive a second input signal applied to said balanced low impedance differential input line preamplifier, the base of said second high gain transistor connected to the base of said first high gain transistor;
• first constant current source means connected to the emitters of said first and second high gain transistors;
• a differential amplifier including third and fourth transistors connected together such that they produce an output signal related to the difference in the input signal applied to the bases of said third and fourth transistors;
• second constant current source means connected to the emitters of said third and fourth transistors;
• a first DC decoupling capacitor connected between the collector of said first high gain transistor and the base of said third transistor;
• and,
• a second DC decoupling capacitor connected between the collector of said second high gain transistor and the base of said fourth transistor.