The Difference between Digital Power Amplifier and Analog Power Amplifier

Because the digital power amplifier works completely different from the traditional analog power amplifier, it overcomes some inherent shortcomings of the analog power amplifier and has some unique characteristics.

1. Overload capacity and power reserve

The overload capability of digital power amplifier circuits is much higher than that of analog power amplifiers. When overloaded, the power amplifier tube works in the saturation zone, and harmonic distortion appears, the degree of distortion increases exponentially, and the sound quality deteriorates rapidly. The digital power amplifier is always in the saturation zone and cut-off zone during power amplification.  As long as the power amplifier tube is not damaged, the distortion will not increase rapidly.

2. Matching of power amplifier and speaker

Due to the large internal resistance of the power amplifier tube in the analog power amplifier, the working state of the analog power amplifier circuit will be affected by the size of the load (speaker) when matching speakers with different resistance values. The internal resistance of the digital power amplifier does not exceed 0.2Ω (the internal resistance of the switch tube plus the internal resistance of the filter). The resistance (4~8Ω) relative to the load (speaker) is completely negligible. Therefore, there is no matching problem with the speaker.

3. Transient intermodulation distortion

Almost all analog power amplifiers use negative feedback circuits to ensure their electroacoustic indicators. In the negative feedback circuit, in order to suppress the parasitic oscillation, a phase compensation circuit is used, which will cause transient intermodulation distortion. The digital power amplifier does not use any analog amplifier feedback circuit in power conversion, thus avoiding transient intermodulation distortion.

4. Sound and image positioning

For analog power amplifiers, there is generally a phase difference between the output signal and the input signal. And when the output power is different, the phase distortion is also different. The digital power amplifier uses digital signal amplification to make the phase of the output signal and the input signal completely consistent, and the phase shift is zero, so the sound image positioning is accurate.

5. Production debugging

Analog power amplifiers have debugging problems at all levels of operating points, which is not conducive to mass production. Most of the digital power amplifiers are digital circuits, which can work normally without debugging, and are especially suitable for mass production.

After reading the difference between the two power amplifiers, the advantages of digital power amplifiers are more prominent. If you want to buy digital power amplifiers, welcome to Guangzhou DSPPA Audio Co., Ltd. We will recommend the most suitable digital power amplifier for you.