Power Amplifier And Audio Source Selection

- Aug 14, 2020-

1. Is the sound source important? How big is the difference between good and bad?


In fact, the answer is quite simple and important! The author has tried some sound sources, the difference is actually quite big, it is not too much to say that it is one ear. If you have listened to high-end audio sources, you may not be able to listen to low-end audio sources, haha


Personal suggestion is to choose a sound source as best as possible when the budget is sufficient, which is very necessary for the sound system. However, if you really don’t have one, choose an economical and practical one as recommended by the next question.


2. Which audio source is better?


It is estimated that this is my answer that will make people lose their glasses. According to the sound sources I have heard, ranked by my favorite sound quality, it is about: mastering> high-end vinyl> ordinary vinyl> advanced tape drive> SACD+ decoding> digital turntable DSD+ decoding> high-end CD> digital turntable lossless + decoding >Mid-end pure CD player>Blu-ray player>Advanced portable machine>Computer + decoding>hifi mobile phone or low-end portable>Ordinary mobile phone>Bluetooth>FM radio


Of course, different products will cause some differences and also affect the rankings, but the overall problem is not big. It is estimated that the above ranking will make many people controversial, welcome to discuss it below, as long as you have heard it yourself instead of just wanting.


Generally speaking, convenience and sound quality are contradictory, which is similar to speakers. The most convenient is undoubtedly the radio, Bluetooth, and ordinary mobile phones, but undoubtedly, the sound quality is also the worst. It is basically useless to meet the requirements of hifi. Hifi phones are quite different now, and the best ones are very close to mid-range portable sound quality, such as LG G7. Computer plus decoding (also known as pc hifi) is a format that many people like, but according to the author's practice, the sound quality of this audio source is really not good. It is said that after adding an interface, it can reach the level of a digital dial (I have not heard of this). However, a random interface on the Internet is more than 1,000, and a digital dial is more than 1,000 (some hundreds of them are also available), so you can figure it out.


One thing I want to say here is that the existence of low-end CDs is not necessary. According to my comparison, Blu-ray players are the most economical sound source-of course, you have to pay the long-term cost of buying discs.


The digital turntable is a very recommended audio source. It combines convenience and price. The sound produced by the built-in or external decoding is completely acceptable, and it is not lost to the form of CD player. Especially when playing SACD format music, the effect is very good. And the brand factor is not that big. However, all of these, in the face of analog audio sources, even tapes, there are gaps. The premise is a good tape and machine. Mastering machine and vinyl, especially the sound quality brought by high-end vinyl, are still the best sound sources in the current audio. However, it is also the most inconvenient. Although the indicators do not seem to be excellent, the effect is two different things.


3. How much do you need to invest in the audio source?


This problem is actually a matter of wealth and frugality. As long as the choice is right, it will not be too bad. The author used a digital turntable with built-in decoding played by a certain great god "amateur". The effect is very good. According to my own evaluation, it won’t be too much for less than ten thousand yuan, but the price is less than two thousand yuan. No good mobile phones can be bought.


If you are not afraid of the later cost of buying CD discs, the Blu-ray player effect is quite good, but it should be the kind with RCA output from Japan, such as Sony and Sharp. Of course, oppo is also available, but it is more expensive.


What I'm really afraid of is that I want to be convenient and well thought out. For example, using a computer to add decoding is difficult. Even if you pay a lot of money, it is not enough.


4. What is the most important in the sound source?


Recording is the most important!


I have seen many people who are extremely obsessed with digital formats to the extent that they care about DSD64 or DSD256. But I don’t care much about the original recording! Many good recordings, even in the mp3 format (320k), are still very good. If you don't compare them carefully, you can't feel the difference between losslessness.


The original mastering and post-mixing, track grabbing and compression also play a key role in it, and the sound quality of many online resources is very unreliable. Many of them use bun CDs, and the effect is really impossible (don't tell me that digital audio sources are the same, unless you never practice, just want to).


However, the original recording is really the most important. There is a problem in front of it, that is, it is congenital disability, and no matter how hard it is the day after tomorrow, there is nothing to do.


5. Is the decoding chip important?


Chip-only theory is common in both enthusiasts and non-enthusiasts. But in fact, the DAC chip is only one of the key factors that determine the sound quality, not the only factor, or even the most important factor. Peripheral circuit design, clock accuracy, analog circuit design, component selection and power supply processing play a vital role in the sound of the final audio equipment.


In fact, the difference brought by decoding chips is getting smaller and smaller, and other places become more important. Good design will give full play to the capabilities of the chip, and good debugging will make the sound replay more charming. These subtle differences in the sound source are the level, and it is worth paying for it.


6. the importance of power amplifier and how much budget is appropriate?


The correct matching of power amplifier and speakers is the key to the normal performance of a system! But this does not mean that the greater the power of the amplifier, the better, unless your speakers need it, the excess power will not do much. On the other hand, in addition to power, power amplifier control (or drive current) is also particularly important. But unfortunately, few power amplifier factories mark this parameter. But many power amplifiers are labeled such as: 100W/8 ohms, 200W/4 ohms, 400W/2 ohms, which indicates that the control power of this power amplifier is very powerful. Although its nominal power may not be high, it has very good control over speakers.


On the other hand, distortion (THD) is also very important. Most power amplifiers are marked with THD: power at 0.01%, which is RMS power. And some brands often bluff people with the power when THD is 1% or even 10%. Japanese-based power amplifiers are usually 120W per channel. Take a closer look, THD is 10% (when converted to 0.1%, even 40W have to hit a question mark).


Therefore, how much budget you spend on power amplifiers depends more on your speakers. Some low-efficiency speakers often require power amplifiers that are several times the price of the speakers. And some high-efficiency speakers, single-ended amplifiers of several watts can also be pushed very well.