Gisen Audio at Guangzhou Prolightsound 2024
Front power amplifier and pure power amplifier
by:Gisen
2020-06-18
Front power amplifier and pure power amplifier
The professional name of the pre-amplifier is: The pre-amplifier is also the most influential part of the whole set of equipment. It is a device that provides a suitable audio level signal and adjusts the sound quality (commonly known as a pre-amplifier, connected between the sound source and the power amplifier).
The professional name of the post-stage power amplifier is: pure post-stage power amplifier. This is the real power amplifier part, which has a great impact on dynamic and low-frequency control. It is a device that simply amplifies the 'front-level' audio signal to provide enough power to drive the speaker speakers (always connected in front of the speaker).
Front power amplifier and pure power amplifier
And the common power amplifier in the general family should be called the front and rear combined amplifier, the combined amplifier.
After power amplifier (pure after power amplifier):
The input signal of the latter stage is very simple, that is, to accept the output of the preceding stage. But the load of the rear stage is the speaker, which is what makes many audio fans and even magazine review writers unsure. The rear stage is the front stage load, which is a high impedance load; the horn is the rear stage load, which is a low impedance load. It looks almost the same, only one word difference, but the high and low impedance makes it easy to push or not move. The front stage is connected to the high-impedance rear stage, which mainly provides the appropriate output voltage because the rear stage amplifier.
The pure final stage power amplifier needs a pre-amplifier to drive it. The pure final stage power amplifier generally has a power of more than a few hundred watts, which is usually used in some professional places, and multiple units work simultaneously to promote different speakers. Therefore, the amplifier circuit does not have a low-level input port and no jacks for high-impedance input signals such as microphones. This requires a pre-amplifier or a mixer to give it a signal to control it. The pre-amplifier and pure post-stage power amplifier are also combined into one, usually the power is less than 300 watts, which is used in smaller places, home use or KTV.
Pre-amplifier (pre-amplifier):
Preamplifier refers to the circuit or electronic equipment placed between the source and the amplifier stage, which is designed to receive the weak voltage signal from the source.
The preamplifier is used to amplify the weak signal. Generally, the signal is first filtered through the electrolytic capacitor to filter out the high-frequency noise signal, and then enter the negative feedback op amp to amplify the signal. Power amplifier generally refers to the power of amplifying an AC signal, which is to amplify the current and voltage of electrical appliances without signal distortion. The front is placed close to the detector, the transmission line is short, the distributed capacitance Cs is reduced, and the signal-to-noise ratio is improved. The signal is preliminarily amplified by the preamplifier to reduce the relative influence of external interference. The front amplifier is designed for high input impedance and low output impedance for impedance conversion and matching.
If you only discuss the technology, the pre-level is more elaborate than the post-level, and it is more difficult to do it. If you want to add a special power line, you must not use the good line in the post-level because of the large current of the post-level. level.
The pre-amplifier is generally connected to the pure post-stage power amplifier, the pre-stage output is connected to the post-stage input terminal, and the post-stage is connected to the speaker. The pre-amplifier is to amplify the voltage, the pure post-stage power amplifier is to amplify the current, the pre-amplifier is the linking device between various sound source equipment and power amplifier, the output signal level of the sound source equipment is relatively low, can not promote the normal operation of the power amplifier The preamplifier plays the role of signal amplification.
characteristic
The pre-amplifier refers to the circuit or electronic equipment placed between the source and the amplifier stage. It is designed to receive the weak voltage signal from the source.
Front power amplifier and pure power amplifier
The pre-amplifier is used to amplify the weak signal. Generally, the signal is first filtered through the electrolytic capacitor to filter out the high-frequency noise signal, and then enter the negative feedback op amp to amplify the signal. The pre-amplifier generally refers to the power of the amplified AC signal, which is the current and voltage of the amplified electrical appliance without distortion of the signal. The front is placed close to the detector, the transmission line is short, the distributed capacitance Cs is reduced, and the signal-to-noise ratio is improved. The signal is preliminarily amplified by the preamplifier to reduce the relative influence of external interference. The pre-amplifier is designed with high input impedance and low output impedance to achieve impedance conversion and matching.
If the technology alone is used, the pre-amplifier requires finer and more difficult to complete than the pure post-amplifier. If you need to add a special power line, you must not use the good line in the post-stage because of the large current of the post-stage It should be the predecessor.
The input signal of the pure final stage power amplifier is very simple, that is, to accept the output of the previous stage. But the load of the pure final stage amplifier is the speaker, which is what makes many audio fans and even magazine review writers unsure. The rear stage is the front stage load, which is a high impedance load; the horn is the rear stage load, which is a low impedance load. It looks almost the same, only one word difference, but the high and low impedance makes it easy to push or not move. The front stage is connected to the high-impedance rear stage, which mainly provides the appropriate output voltage because the rear stage amplifier.
Amplifiers are generally divided into pre-amplifiers, post-amplifiers and merged-amplifiers. The merger combines the pre-amplifier and the post-amplifier into one machine. The front stage is used to preliminarily amplify the signal and adjust the volume; the rear stage is to amplify the signal from the front stage to boost the speaker.
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