Electronics for Vinyl

Chapter 4

Preamp Architecture

The purpose of this chapter is to look at how phono amplifier stages fit into the architecture of a complete preamplifier that can handle a variety of input source types.

Passive Preamplifiers

Some sort of preamplifier or control unit is required in all hi-fi systems, even if its only function is to select the source and set the volume. You could even argue that the source-selection switch could be done away with, if you are prepared to plug and unplug connectors, leaving a “preamplifier” that basically consists solely of a volume- control potentiometer in a box.

I am assuming here that a selector switch will be required, and that gives us the “passive preamplifier” (oxymoron alert!) in Figure 4.1a.

There is of ...