Professional power amplifier part of the circuit parameters

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1. Some circuits in professional power amplifiers
(1) The power circuit has a large power capacity, often using a toroidal transformer, commonly known as "ring cow", a large-capacity filter capacitor, called "large pond", to ensure sufficient power supply at the peak of the work. High-power devices such as the last-stage power tube (commonly used by Sanken and Toshiba) use products with higher current and higher withstand voltage than the rated value. In the output stage with severe heat generation, a larger heat sink is needed for heat dissipation. Most of them will also use a cooling fan for forced air cooling.
(2) A variety of protection circuits, such as DC protection, short circuit protection, overheat protection, sensitive overheat management system, input (output) overload protection, soft start protection, active limiting protection.
2, the main parameters of the power amplifier selection power amplifier mainly depends on output power, frequency response, distortion, signal to noise ratio, output impedance, damping coefficient and other parameters.
(1) The unit of output power is W. Due to the different measurement methods, there are some different names, such as rated output power, maximum output power, music output power, and peak music output power. Some fish manufacturers often use this to confuse users. The peak power is the maximum music power that the amplifier can output when the amplifier volume is adjusted to the maximum within the allowable distortion condition. The rated output power refers to the maximum output power when the distortion is less than a certain value, also called the maximum useful power. Generally, the peak power is greater than the music power, and the music power is greater than the rated power. In general, the peak power is 5-8 times the rated power.
(2) Frequency response: indicates the unevenness of the level gain within the operating frequency range of the power amplifier. The straightness of the frequency response curve is expressed in decibels (dB). The frequency response of a home Hi-Fi amplifier is generally 20 Hz to 20 kHz, and 1 dB. The wider the frequency response range, the better.
(3) Distortion: The ideal power amplifier should be to amplify the input signal without change. In fact, the amplified signal of the power amplifier is compared with the input signal, and different degrees of distortion are generated. This distortion is distortion. Expressed as a percentage, the smaller the value, the better. The distortion of the power amplifier includes harmonic distortion, intermodulation distortion, cross distortion, clipping distortion, transient distortion, and transient intermodulation distortion.
(4) Signal-to-noise ratio: refers to the ratio of the signal level to the various noise levels of the power amplifier output, expressed in dB. The signal-to-noise ratio of a typical home Hi-Fi amplifier is above 60 dB.
(5) Output impedance: The equivalent internal resistance exhibited by the speaker.
(6) Damping coefficient: refers to the ratio of the load impedance of the power amplifier to the actual impedance of the power amplifier. A large damping coefficient means that the output resistance of the power amplifier is small, and the output impedance of the power amplifier directly affects the low-frequency Q value of the speaker system, thereby affecting the low-frequency characteristics of the system. It is generally desirable that the output impedance of the power amplifier is small and the damping coefficient is large. The damping coefficient is between tens and hundreds, and the damping coefficient of professional power amplifiers can be as high as 200 or more.