The role of the power amplifier

1. Power amplifier People call it "amplifier". Its function is to amplify the weak signal from the sound source or pre-amplifier. You can consider promoting the soundproofing of the speaker. You must know that if you have a good sound system, the power amplifier will not work. without.
2. As for its function, this is based on the different components used. "IC power amplifier" is rarely seen in HI-FI functions because its timbre is not as good as the two power amplifiers. Here, let’s briefly talk about power amplifiers can be divided into three categories: “professional power amplifiers”, “civilian power amplifiers” and “special power amplifiers”. The "professional power amplifier" is more suitable for sound amplification in conferences, performances, halls, halls, venues, and halls. But most of the "professional power amplifier" sound is used for HI-FI playback, but the sound of this kind of power amplifier is dry and hard to listen to.

Power amplifier function key diagram
The function of each key of the power amplifier:

1. MIC1: microphone 1, GA: the volume dimming potentiometer of microphone 1 (that is, the volume switch knob).

2.BASS: Bass potentiometer for microphone 1.

3.MID: Midrange potentiometer for microphone 1.

4. TRE: Treble potentiometer for microphone 1. Then the latter will not be repeated.

5.INPUT: It is the selection button of the audio source. Then the following two buttons are not sure what the function is.

6.EFFECT: It is the microphone effect level knob. That is the so-called effect volume.

7.DEL: The delay of the microphone effect.

8.REP: echo times.

The performance index of the power amplifier
The main performance indicators of the power amplifier include output power, frequency response, distortion, signal-to-noise ratio, output impedance, damping coefficient, etc.

Output power: the unit is W, because the measurement methods of each manufacturer are different, so there are some names with different names. Such as rated output power, maximum output power, music output power, peak music output power.

Music power: refers to the instantaneous maximum output power of the power amplifier to the music signal under the condition that the output distortion does not exceed the specified value.

Peak power: refers to the maximum music power that the amplifier can output when the volume of the amplifier is turned to the maximum without distortion.

Rated output power: the average output power when the harmonic distortion is 10%. Also known as the maximum useful power. Generally speaking, the peak power is greater than the music power, and the music power is greater than the rated power. Generally speaking, the peak power is 5-8 times the rated power.

Frequency response: Indicates the frequency range of the power amplifier and the unevenness within the frequency range. The flatness of the frequency response curve is generally expressed in decibels [db]. The frequency response of household HI-FI amplifiers is generally 20HZ--20KHZ plus or minus 1db. The wider the range, the better. The frequency response of some top-quality power amplifiers has reached 0--100KHZ.

Distortion: The ideal power amplifier should amplify the input signal and faithfully restore it without any change. However, due to various reasons, compared with the input signal, the signal amplified by the power amplifier often produces different degrees of distortion, which is called distortion. Expressed as a percentage, the smaller the value, the better. The total distortion of the HI-FI power amplifier is between 0.03% and 0.05%. The distortion of the power amplifier includes harmonic distortion, intermodulation distortion, crossover distortion, clipping distortion, transient distortion, and transient intermodulation distortion.

Signal-to-noise ratio: refers to the ratio of the signal level output by the power amplifier to the noise level, expressed in db, the larger the value, the better. Generally, the signal-to-noise ratio of household HI-FI amplifiers is above 60db.

Output impedance: The equivalent internal resistance presented to the speaker is called output impedance.