ABSTRACT
This chapter covers hybrid power amplifiers design. Solid-state power amplifiers and vacuum tube power amplifiers have their own pros and cons. Solid-state power amplifiers are the favorable choice when high current and high power are needed. However, it is well known that solid-state devices and vacuum tubes produce a different sound. It is commonly believed that a vacuum tube amplifier produces good mid-range sound while a solid-state amplifier produces good bass. If a hybrid power amplifier is made with a combination of vacuum tubes and solid-state devices, the amplifier may benefit from both technologies. Several examples of hybrid power amplifier design are covered in this chapter. The hybrid power amplifiers employ vacuum tubes for the input stage and voltage amplifier stage, and solid-state power devices for the output stage. Examples of unbalanced input-unbalanced output and fully balanced hybrid power amplifiers are given.
