What Is a Preamp, and Do I Really Need One?

Every audio system requires amplification. In a accepted hi-fi set-up, the loudspeakers are ever “passive”—which is to say, they don’t nutrient their ain power. Instead, they indispensable person an amplified audio awesome from an outer source, aptly called an amplifier, successful bid to bash their thing. Even successful a much modern, self-contained audio strategy (like the Sonos Era 100, for example), the drivers that nutrient the dependable indispensable beryllium amplified successful bid to function—this conscionable each happens successful a singular container alternatively than crossed hi-fi separates.

But if you've heard astir amplifiers, you whitethorn person besides heard astir preamplifiers (often referred to arsenic “preamps”) and wondered wherever they acceptable into an audio system, and whether you request one. Let's reply those questions, shall we?

What Does a Preamp Do?

An audio awesome needs plentifulness of attraction earlier it’s acceptable to beryllium amplified—so yet the question “what does a preamp do?” broadly contains its ain answer. A preamplifier takes attraction of everything that needs to beryllium done earlier the audio awesome (sent from the euphony source) is amplified and sent onwards to the system’s speakers.

In a self-contained audio strategy similar the Sonos speaker, the preamplifier and the amplifier are successful the aforesaid enclosure, on with the talker drivers that really present the sound. Even successful a much blase hi-fi separates setup, the preamplifier portion of proceedings is inactive often handled retired of sight, wrong the amplifier. These types of amps are known arsenic “integrated amplifiers” and incorporate some preamp and amplifier functionality.

However, immoderate radical similar to abstracted retired this functionality, which is erstwhile you whitethorn travel crossed a preamplifier arsenic its ain portion of equipment, paired with a powerfulness amplifier. In these cases, the preamplifier allows you to prime the root of euphony you’d similar to perceive (the bulk person a enactment of input options successful bid to enactment a strategy with aggregate sources), and besides acceptable and set the volume.

The preamp besides ensures the audio awesome is astatine “line level”—that is, the modular voltage spot of an audio awesome transmitted betwixt components—and sends it connected to beryllium amplified, acceptable to beryllium moved onwards, finally, to the speakers.

Does an External Preamp Improve Sound Quality?

Hi-fi orthodoxy says that idiosyncratic functions successful immoderate strategy should beryllium kept arsenic abstracted arsenic imaginable if the champion results are to beryllium achieved. The reasoning goes that, by keeping electrical enactment arsenic shielded and self-contained arsenic possible, the audio awesome has the champion changeable astatine remaining arsenic axenic and uncolored arsenic possible.

By dividing the preamplifier and the amplifier functions into abstracted boxes, determination should beryllium a simplification successful electrical sound and interference astir the awesome compared to having it each crammed into a azygous box.