A power amplifier doesn't just make things louder. It takes the delicate voltage signal from your preamp and converts it into current—real electrical muscle that can push and pull the voice coils in your speakers back and forth fast enough to create sound. It's a brute-force task that requires finesse, because while you're generating watts of power, you still have to preserve every subtle detail of the music.
The challenge is that speakers aren't simple resistors. Their impedance changes with frequency, sometimes dipping low enough to demand huge amounts of current from the amplifier. A good power amp has to stay stable and linear no matter what the speaker throws at it—whether it's an easy eight-ohm load or a nightmare two-ohm dip in the bass region that would make a lesser amp clip or shut down.
That's why the power supply is everything in an amplifier. You need massive capacitor banks to store energy for musical peaks, heavy transformers to deliver steady current, and regulators that keep the voltage rails stable under dynamic load. Skimp on the power supply and you'll hear it immediately—compressed dynamics, weak bass, a sense that the music can't quite breathe.
Then there's the circuit topology. Some designers swear by Class A operation, where the output devices are always conducting and never switch off. It's inefficient and runs hot, but it can sound incredibly smooth and linear. Class AB is more common—a compromise that gives you most of the purity of Class A with better efficiency. Class D switching amps are lighter and cooler still, and modern designs have gotten good enough that the sonic compromises are minimal if the implementation is done right.
At PS Audio, we've built all three types over the years. What I've learned is that no single topology is inherently better. What matters is how well the circuit is executed, how robust the power supply is, and whether the whole design works in harmony with the speakers it's driving. A great amplifier doesn't have a sound of its own—it just delivers whatever the preamp sends it with enough power and control to make the speakers disappear.
When that happens, you stop thinking about watts and specs and circuit classes. You just hear music with all the impact, delicacy, and presence it deserves.
