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Door staff@engadget.com (Roger Fingas) - 04 Oct 2026
On their own, most audio signals aren't strong enough to be heard clearly. For a demonstration of this, all you need is a turntable with its speakers disabled. If you listen closely, you'll hear something called "needle talk" — the stylus running along the vinyl grooves. This is quiet, and it may not even be distinguishable as music. For you to hear anything meaningful, all sound systems need an amplifier to increase the strength of a signal before output. It's important to match an amp to the power and impedance specs of your speakers, measured in watts and ohms, respectively.
Amps accomplish more than just an increase in volume. Any quality amp will let you adjust gain (the amount of signal boost) and shape sound to your preferences via its equalizer (EQ). You might tweak frequencies for heavier bass or clearer vocals, for example. It's important to get gain and EQ settings right not just for pleasing sound, but to prevent clipping, distortion or even hardware damage.
Let's take a moment to distinguish between amps and preamps. The latter simply raise audio up to line level for correct gain throughout your sound system, meaning that you still need an amp to power your speakers. Some amps have a preamp built-in, streamlining the audio chain.
That leads us to the question of whether you need to buy an amp at all. The truth is that in many cases, you don't. Many, if not most, consumer speakers are active, meaning that they already have integrated amps, as evidenced by their individual power cords. Only passive speakers require external power sources, and even then, you may not need a dedicated unit. Receivers often incorporate both amp and preamp functions, making them a one-stop shop. Exceptionally power-hungry systems may demand an amp on top of that. For example, elaborate Dolby Atmos setups that exceed the number of channels your receiver can power simultaneously will need an amp.
Most people should probably opt for a solid-state amp rather than a tube-based one. While tube models famously provide a "warmer" sound and are visually slick — especially for fans of Fallout's brand of retrofuturism — they typically deliver 50W or less apiece, making them unsuited to surround-sound configurations unless you're willing to spring for several of them. Tubes also require more maintenance, namely swapping them as they wear out. Trying to run a home theater based on tube amps would be an expensive exercise in futility.
Amps accomplish more than just an increase in volume. Any quality amp will let you adjust gain (the amount of signal boost) and shape sound to your preferences via its equalizer (EQ). You might tweak frequencies for heavier bass or clearer vocals, for example. It's important to get gain and EQ settings right not just for pleasing sound, but to prevent clipping, distortion or even hardware damage.
Let's take a moment to distinguish between amps and preamps. The latter simply raise audio up to line level for correct gain throughout your sound system, meaning that you still need an amp to power your speakers. Some amps have a preamp built-in, streamlining the audio chain.
That leads us to the question of whether you need to buy an amp at all. The truth is that in many cases, you don't. Many, if not most, consumer speakers are active, meaning that they already have integrated amps, as evidenced by their individual power cords. Only passive speakers require external power sources, and even then, you may not need a dedicated unit. Receivers often incorporate both amp and preamp functions, making them a one-stop shop. Exceptionally power-hungry systems may demand an amp on top of that. For example, elaborate Dolby Atmos setups that exceed the number of channels your receiver can power simultaneously will need an amp.
Most people should probably opt for a solid-state amp rather than a tube-based one. While tube models famously provide a "warmer" sound and are visually slick — especially for fans of Fallout's brand of retrofuturism — they typically deliver 50W or less apiece, making them unsuited to surround-sound configurations unless you're willing to spring for several of them. Tubes also require more maintenance, namely swapping them as they wear out. Trying to run a home theater based on tube amps would be an expensive exercise in futility.