What is the difference between digital power amplifier and ordinary power amplifier?

1. The power amplifier principle is different:

The so-called digital power amplifier is a method of digital signal processing in the front. After the audio signal or digital audio signal is input, the existing digital audio processing integrated circuit is used to complete some processing of the sound field, digital delay and reverberation functions, and then stop audio amplification through the analog power amplifier module.

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

2. The difference between overload capacity and power reserve:

The overload capacity of the digital amplifier circuit is much higher than that of the analog amplifier circuit. Analog amplifier circuits are classified as Class A, Class B or Class AB power amplifier circuits. When overloaded, the amplifier tube works in the saturation region and harmonic distortion occurs. The distortion increases exponentially and the sound quality deteriorates sharply.

Extended information:

The digital power amplifier in the power amplification has been in the saturation region and cut-off region, as long as the amplifier tube is not damaged, the distortion will not increase rapidly.

Since the digital power amplifier uses a switching amplifier circuit, the efficiency is extremely high, reaching 75% to 90% (the analog power amplifier efficiency is only 30% "50%), and it basically does not generate heat during operation.

Therefore, it has no static current consumption of analog power amplifier, and almost all energy is reserved for audio output. In addition, there is no analog amplification and negative feedback before and after, so it has better "dynamic" characteristics, good transient response and strong "bursting feeling.

3. The difference between crossover distortion and mismatch distortion:

Analog class B amplifier in the zero-crossing distortion, this is due to the transistor in the small current nonlinear characteristics of the negative, positive intersection of the output waveform distortion (small signal transistor will work in the cut-off region, no current through, resulting in serious output distortion). The digital amplifier only works in the switching state and does not produce cross-over distortion.

The characteristics of the push-pull amplifier are not uniform, resulting in mismatch distortion of the output waveform. However, the digital power amplifier has no special requirements for the pairing of the switches and can be used without strict selection.