A practical complementary-symmetry amplifier is described in which both positive and negative feedback are used; bootstrap positive feedback to increase output power and negative feedback to reduce distortion. The basic amplifier circuit can be used to obtain power outputs varying from tens of milliwatts to tens of watts at good efficiency levels. Because of the circuit simplicity and wide power output capabilities, this amplifier is practical for use in portable radio receivers, portable megaphones, automobile receivers and various other portable audio equipments. The amplifier consists of a Class A driver stage and a direct-coupled complementary-symmetry output stage. As no transformers are used the amplifier can be made relatively compact and light in weight. Design parameters and data on performance of a 100-milliwatt, a 3-watt and a 12-watt amplifier are presented and discussed.
Click to purchase paper as a non-member or login as an AES member. If your company or school subscribes to the E-Library then switch to the institutional version. If you are not an AES member and would like to subscribe to the E-Library then Join the AES!
This paper costs $33 for non-members and is free for AES members and E-Library subscribers.