When you buy a power amplifier device and you are hesitant, when you face a large and small power amplifier, I don’t know how to choose it. How to judge its pros and cons? Xiaobian is here to help you give you some suggestions, so that you will no longer have headaches and troubles when facing such problems.

How to identify poor quality amplifiers:

First, it is aimed at many people who think that the power amplifier is "sinking better and better". Inferior power amplification uses a toroidal transformer, and many use a double-ring cow with fever. However, the quality of this kind of ring-shaped silicon steel sheet is very poor, and the winding process is not good. It causes low efficiency and low actual power. Especially when it is quiet, it is easy to hear the ring cows humming.

Second, it is a large-capacity domestic capacitor filled with imported brand-name capacitors. Some manufacturers even used a backlog of early capacitors to repackage and refill new capacitors. The actual withstand voltage and capacity of these capacitors simply do not reach the nominal value. These types of capacitors are generally lighter than the true ones.

Three, is a low-end 4558 or 082 charge 5532 and other high-end power amplifier. Sometimes I find that a lot of so-called 5532 is actually 4558 polished. There are also domestically produced power amplifier tubes filled with imported tubes, especially Toshiba tubes with the most fakes.

Four, inferior power amplifiers often have 5-channel or even 7-channel output. But in fact, the surround and center channels of many amplifiers are connected by series resistors from the left and right main channels. Although some amplifiers have independent amplification circuits, they are only subjected to simple delay processing, and there is no dedicated decoding circuit and sound field processing circuit. When identifying such amplifiers, if you find that the surround and center channels cannot adjust the volume separately, it must be a false surround from the main channel series resistor. If there is a nominal Dolby Pro Logic decoding function and no noise test. Or if the surround speaker rings when only the mono signal is input, the amplifier is a pseudo surround sound amplifier. For amplifiers using technologies such as SRS and Q-Sound, the true and false can also be identified by comparing the audition to turn the surround function on and off and selecting different surround modes. Here, we need to remind everyone that some audio manufacturers have actually adopted the Dolby decoder chip such as M69032, but they have not passed the Dolby certification and also posted the Dolby logo. Such power amplifiers cannot guarantee the necessary performance indicators such as channel separation, and are also counterfeit.

Five is a lack of comprehensive protection. Although the inferior machine has the function of starting and anti-shock protection, most of the necessary overcurrent, overvoltage and output DC protection functions are omitted. The reliability of the whole machine is poor, and if there is a problem, it is likely to burn an expensive speaker unit. For the identification of such fake methods, one is to check whether the design has perfect protection functions by looking at the circuit diagram. The second is short-circuit short-circuit output, if the amplifier does not appear protection action. It is very likely that these protection circuits are omitted, at least the tuning is poor.

Six, it is based on Class B filling, one-sided pursuit of multi-function and appearance while ignoring the level of circuit design, and using this as a selling point. This is all about "advanced" fake tricks. For these "characteristic" amplifiers, if consumers are not familiar with audio equipment, it is best to ask people who know how to help, and try to choose a sound manufacturer's products more reliable.

Finally, I would like to make three suggestions. First, adhere to the principle of “enough and easy to use”, and do not excessively pursue functions and appearance. For Hi-Fi enthusiasts, a two-element AV amplifier may not be as good as a thousand-dollar dual-channel amplifier. The second is to remember that the amplifier and speakers should be properly matched. The third is to satisfy the principle of your own ears. Don't be fooled by the sound of the "disintegration" specially prepared by the dealer, and bring a few high-quality CD test machines that you are familiar with, which may benefit you a lot.

Basic settings for professional amplifiers:

Electrical sound: This function is divided into three options: FULL - full tone; HP: Qualcomm - only the frequency above the crossover point (such as 80Hz) is passed, this setting is mainly used for middle and high speakers; LP: Low Pass—Puts only frequencies below the crossover point (such as 80Hz), which is primarily used for woofer speakers. Some of them are also set to the adjustable crossover point, which can be set according to different system design, and some are fixed at 80Hz, 100Hz, 120Hz.

Signal input selection: There are two input methods: RCA signal (low voltage) and host speaker cable (high level). In order to obtain good sound quality, you can choose RCA signal input (ideal frequency response and excellent signal-to-noise ratio, but only if the host has RCA output). If the host has no RCA output or retains the original car, only the tape is selected. A high level input amplifier. In addition, many amplifier products have one or two sets of signal output (lineouput) to transmit signals to another amplifier, which not only saves the cost of the crossover, but also guarantees excellent sound quality, because different merchants The approach taken when the signal output is not adequately distributed varies, and some processing methods can degrade the sound quality.

Input gain adjustment: This knob is used to adjust the input voltage of the amplifier to the optimal matching state with the signal voltage transmitted from the host to ensure that the sound will not be distorted.

Bridge output: When the amplifier is bridged, the output power can be increased by a factor of 2, which makes it more useful when needed (such as to push the subwoofer)