How to choose a good power amplifier

As for the audio amplifier, how do we judge whether it is good or bad? Today, Beilarly professional audio engineers give you a few suggestions to let you no longer have headaches and troubles when facing such problems.

1. It is aimed at many people that the power amplifier "sinks the better", the inferior power amplifier uses a toroidal transformer, and many use a double-ring cow with a fever. However, the quality of this type of silicon steel sheet is very poor, and the winding process is not enough. As a result, the efficiency is low and the actual power is small, especially when it is quiet, it is easy to hear the ringing cow humming.

2. The imported capacitors are filled with large-capacity and small-capacity domestic capacitors. Some manufacturers even use the backlog of early capacitors to update the packaging and install the new capacitors. The actual withstand voltage and capacity of these capacitors simply cannot reach the standard value. Such capacitors are generally lighter than genuine ones.

3. The low-end 4558 or 082 charge 5532 and other high-end power amplifier. Sometimes I found that many of the so-called 5532 were actually polished from 4558. There are also the most fakes filled with imported tubes, especially Toshiba tubes, with domestic power amplifier tubes.

4. The inferior power amplifier often has 5 channel or even 7 channel output. But in fact, the surround and center channels of many amplifiers are derived from the series resistance of the left and right main channels. Although some amplifiers are equipped with independent amplification circuits, they are only subjected to simple delay processing, and there is no dedicated decoding circuit at all. And sound field processing circuit. If you find that the surround and center channels cannot be adjusted separately when identifying this type of amplifier, it must be a false surround from the main channel in series with a resistor.

If it is nominally equipped with Dolby directional logic decoding function but does not have noise test, or the surround speakers also sound when only a mono signal is input, the amplifier is a pseudo surround sound amplifier. For power amplifiers that use technologies such as SRS and Q-Sound, the true and false can also be identified by comparing the audition to turn on and off the surround function and selecting different surround modes. It is also necessary to remind everyone here that although some audio manufacturers have actually adopted Dolby decoding chips such as M69032, they have not passed Dolby certification and also affixed the Dolby logo. Such a power amplifier cannot guarantee the necessary channel separation and other performance signs, and is also a fake.

5. There is a lack of complete protection functions. Although inferior machines have boot anti-shock protection functions, most of them omit the necessary over-current, over-voltage and output DC protection functions, resulting in poor reliability of the whole machine. If there is a problem, it may burn Expensive speaker unit. For the identification of this kind of fake method, one is to check whether the design has perfect protection function by looking at the circuit diagram; the second is to short-circuit the output terminal for a short time, if the power amplifier has no protection action. It is very likely that these protection circuits are omitted, or at least poor adjustment.

6. Use Class B to fill Class A, one-sided pursuit of multi-function and appearance without ignoring the level of circuit design, and use this as a selling point. This is all "advanced" fraud. For these "characteristic" power amplifiers, if consumers are not familiar with audio equipment, it is best to ask someone who is knowledgeable to help you choose, and try to choose the products of audio manufacturers to be more reliable.

Finally, I would like to make three suggestions for friends who are ready to buy power amplifiers. First, adhere to the principle of "enough and easy to use", and do not excessively pursue function and appearance. For FI-FI enthusiasts, a two thousand yuan AV amplifier may not be as good as a two thousand yuan two-channel amplifier. The second is to remember that the power amplifier and speakers should be properly matched. The third is to satisfy the principle of your ears. Do n’t be fooled by the sound of “disruption” specially prepared by the dealer. Bringing a few high-quality CD test machines that you are familiar with may benefit you a lot.