The 10 Best Mini Stereo Amplifiers

Live Loudly, Listen Louder

Unfortunately, the OEM versions built into vehicles, portable devices, and Blu-ray players often leave audiophiles begging for more hi-fidelity solutions.

The Importance Of Being Amplified

Fundamentally speaking, amps aren't so intimidating. They add additional power to a low-amplitude electrical impulse from a DVD player, car stereo head unit, digital-to-analog converter, turntable, 8-track player, or similar, which increases the output current to a strong enough level to move a cone. But moreso than many fields, audio engineering is beset with a flood of products, many of which are just barely different. This jungle can be tough to navigate, and at the end of the day, what sounds the best is usually the best choice. And it helps to have a basic understanding of the technical requirements of modern technology. After all, matching the right equipment can be the difference between bumping some fire bass in your car, and lighting your car on fire.

It's important to select an amp that supplies the right level of power for your specific system.

It's important to select an amp that supplies the right level of power for your specific system. Speakers with higher impedance ratings draw more power, thus calling for a larger amp. In car audio, many mid- and upper-range speakers operate at a nominal 4 to 8 ohms, while subwoofers generally run between 1 and 4 ohms. Overly large cones can overwork and damage the unit, while an overpowered and imperfectly wired amp can result in costly blowouts.

Aside from impedance, astronomical wattage claims also abound in the amplifier world. Peak capacities are only relevant at a certain point, and even the advertised RMS doesn't necessarily reflect the exact performance of a given model. So, it's important to analyze all levels of objective and subjective testimony regarding each contender.

Finally, the signal treatment portion of a sound system consists of two modules: amplifiers and preamplifiers, or preamps. The preamp performs a number of functions, such as receiving and managing various inputs and providing a main attenuator. It also adds a low level of power to any incoming signals that may be too weak for the main unit to process. The main circuit then takes the regulated and readable source and adds volume, equalization, and effects, preparing the new and improved signal for its eventual path to a large cone. Most options available in North America combine both of these stages in a single device, which makes installation easier and ensures that the components work together safely and effectively. Still, because of their potentially low profile and increased sound quality, some audiophiles do opt to use standalone preamps.

A Quick Class On Classes

At first glance, it looks like the comparison of the A, B, AB, and D classes is a complex one, full of nuance and specialized hardware. It is.

Classes are determined by the configuration of their circuitry, and the different types all have varying strengths and levels of efficiency. Less efficiency effectively means high excess heat dissipation, both a waste of energy as well as a danger to the component.

This somewhat newer consumer option triangulates and translates messy input signals into square wave patterns, at great benefit to efficiency and operating temperature.

Widely regarded as the most true-to-signal design, the class A construction supplies constant power to the transistors responsible for amplification, whether or not a signal is currently present. Because there's no threshold level needed to trigger this power availability, the loudest, softest, and most intricate parts of the signal are readily powered and sent to speakers, with maximum clarity and minimal distortion. The drawback to that is a constant stream of wasted energy, which turns into residual heat, the mortal enemy of microscopic transistors.

Also known as push-pull setups, the class B schematic consists of twin transistors at the output end of each circuit. These transmit exact mirror images of each other's signal, thus balancing out the power draw, and making them roughly twice as efficient as their single-switch cousins. Further, they draw power dynamically, significantly reducing dangerous heat dissipation. The drawback is that as the two waveforms approach baseline, they pass through a dead zone as the transistors simultaneously switch on or off, resulting in crossover distortion that can cause harsh and loose-sounding tones. The creatively named AB type combines both, utilizing minimal, continuous power to a pair of transistors for quick and clean response. The baselines of these two inverted-signal switches are slightly offset, creating overlap near the center and preventing dropout as the waveforms balance.

Class D, on the other hand, is an entirely different beast. This somewhat newer consumer option triangulates and translates messy input signals into square wave patterns, at great benefit to efficiency and operating temperature. Due to past issues with sound quality, this particular design is still gaining traction, though its been refined and now receives praise for its incredibly low profile and high efficiency.

Every part of a custom setup plays an important role, and the amplifier itself has the power to make or (literally) break the rest of the system. While there are a ton of options to choose from, they continue to get more efficient and less expensive, all while sounding better.

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