ABSTRACT
This chapter covers the phono-stage amplifiers design. Since RIAA equalization is needed for phonograph record playback, it is often embedded in the phono-stage amplifier with sufficient voltage gain required for moving magnet (MM) and moving coil (MC) cartridges. The gain for an MM phono-stage amplifier is generally around 35–40dB while it is 60–70 dB for an MC phono-stage amplifier. Given such a high gain, the inherent noise of a phono-stage amplifier is a primary concern. Therefore, a well-designed phono-stage amplifier must have accurate RIAA equalization, high gain as well as low noise. This chapter covers various types of RIAA equalization, including active, semi-active, and passive. The amplifying devices include vacuum tube, JFET, BJT and op-amp. Examples for unbalanced input–unbalanced output MM and MC phono amplifier design examples are discussed in details. Several potential amplifier configurations that can be used to implement fully balanced phono-stage amplifiers are also given.
