Recently, we had a customer drive a couple hours to our store. Along with him, he brought his Class D Amplifier so he could do a side by side comparison. He compared his current power amplifier with the Parasound A21. Having been a Parasound dealer for several years now and being very familiar with the quality of products they sell, we knew the Parasound was going to sound superior. However, the difference in quality was absolutely mind-boggling. The Parasound sound is more cleaner, accurate and crisper. The Amp being compared was a Class D amplifier while the Parasound A21 is a class A/AB amplifier. After hearing the tremendous sound difference in person, the customer ended up purchasing a Parasound A51 with absolutely no regrets. Since we are discussing the comparison of power amplifiers, here is a quick list of the different types of classes associated with amplifiers and the differences between each class:
- Class D amplifiers are models of efficiency, but with a loss of detail and fidelity
- Class B amplifiers generally introduce some crossover distortion, but move away from Class D, G, and H’s extreme non-linearity.
- Class AB amplifiers may introduce some crossover distortion, but they get closer to the ideal of Class A for most of its operating regime.
- They are indeed the best compromise of performance versus cost.
- Class A amplifiers introduce no crossover distortion and are the most desirable amps to own, but they are expensive, run hot, and have to be very well-built.