Traditional products in the market have faced declining profit margins for both dealers and manufacturers due to homogenization effects, technological advancements, and the national emphasis on energy conservation and environmental protection. As a result, replacing analog amplifiers with digital amplifiers has become an inevitable trend. Digital amplifiers possess advantages that analog amplifiers simply cannot match.
In theory, if an ideal switching device could be developed, the efficiency of a digital amplifier could reach 100%. However, no company in the market has yet achieved such a perfect switching power device. Inevitably, power conversion involves some heat generation and minor energy loss. The level of loss varies depending on the MOSFET manufacturer, packaging process, and the design margin reserved for MOSFETs. Nevertheless, digital amplifiers consistently achieve efficiencies above 90%, which is unattainable for analog amplifiers.
Unlike traditional analog amplifiers, digital amplifiers operate with a fundamentally different working principle, overcoming inherent limitations of analog designs while introducing unique characteristics:
Elimination of Crossover Distortion
In analog Class B amplifiers, crossover distortion occurs near the zero-crossing point due to the non-linear behavior of transistors at low currents. Digital amplifiers, on the other hand, work purely in switching mode, completely avoiding crossover distortion. Since they generate minimal heat and do not require quiescent current consumption, nearly all energy is reserved for audio output. With no reliance on analog amplification or negative feedback, digital amplifiers deliver superior dynamic performance, excellent transient response, and an exceptionally powerful “live impact” effect.
Overload Capability and Power Reserve
Digital amplifier circuits demonstrate significantly stronger overload capability compared to analog amplifiers. Analog amplifiers, which commonly use Class A, B, AB, or H topologies, operate in the linear region under normal conditions. Once overloaded, their transistors enter the saturation region, causing harmonic distortion to rise exponentially, leading to heat buildup, power loss, and rapid degradation in sound quality. In contrast, digital amplifiers operate strictly between saturation and cutoff regions. As long as the transistors remain intact, distortion does not increase drastically. Moreover, with switching frequencies ranging from tens of kilohertz to several hundred kilohertz, digital amplifiers offer fast conversion and rapid response.