How deep is the home theater amplifier? How to judge the merits of the amplifier?

For the home theater amplifier, how do we judge whether it is good or bad? Here, the home theater network gives you some suggestions, so that you can no longer have headaches and troubles when facing such problems.

How should the amplifier be chosen?

How to identify inferior power 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 enough. 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.

Third, the 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.

Fourth, inferior power amplifiers often have 5-channel or even 7-channel output. But in fact, many of the amplifier's surround and center channels are connected by the left and right main channel series resistors. 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.

Fifth, there is a lack of comprehensive protection functions. Although the inferior machine has the function of starting and anti-shock protection, most of the necessary over-current, over-voltage 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 the expensive speaker unit. For the identification of such fake methods, one is to check whether the design has perfect protection function 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 have been omitted, at least the tuning is poor.

Sixth, 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 the audio manufacturer's products more reliable.

Finally, I would like to offer three suggestions to friends who are ready to buy a power amplifier. First, adhere to the principle of "enough, easy to use", do not excessively pursue function and appearance. 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 dealers. Bringing a few high-quality CD test machines that you are familiar with may benefit you a lot.

Basic setting function of professional amplifier

From a functional point of view, most of the current power amplifier products already have the following functions.

Electronic crossover: This function is divided into three options: FULL—full tone; HP: Qualcomm—only allows frequencies above the crossover point (such as 80Hz) to pass, this setting is mainly used for middle and high speakers; LP: low pass— Only pass frequencies below the crossover point (eg 80Hz), this setting is mainly used for the woofer. 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 frequencies of 80Hz, 100Hz and 120Hz. Welcome to China Home Theater Network

Signal input selection: There are two input modes: RCA signal (low voltage) and host speaker line (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 by the host to ensure that the sound will not have any distortion.

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

Tone adjustment: There are quite a few products with bass (Bass) and Tweeter adjustments, which can be boosted or attenuated at 45Hz and 10KHz respectively. The adjustment range is between 0dB and 12dB, which can make the replayed bass more full. Deep, the treble is clearer and more transparent.