Can high-definition video players be HIFI?

Electronics Enthusiasts Network: Currently, many players support the playback of APE/FLAC/WAV. Can players that can play these music meet the HIFI standard? Here we can try to explain the principle to let everyone know this issue.

The main purpose of a video player is to decode high-definition video, and the design concepts of analog and digital are fundamentally different. Just from the grounding point of view, they are two different concepts. Whether the DAC ground line is good or not directly affects the audio output index by 2-3 times. Here we explain how to achieve HIFI from the perspective of system design.

1. HIFI is all about power supply. A bad power supply will directly affect the performance of audio output.

2. The digital part of HIFI is the problem of clock jitter and signal output quality

3. The data flow direction of the digital dial determines the uniqueness of the output data

4. More importantly, HIFI is a culture and a life attitude.

After we have listed these necessary conditions, we will start to discuss how to build a machine to achieve the ultimate in performance based on the above requirements.

1. It is best to use a linear power supply. As we all know, the concept of switching power supply amplifiers was short-lived and eventually disappeared. Why? In fact, to put it bluntly, pure digital things are always close to analog, and can never be exactly the same as analog. LP lost to CD not because the sound of LP is bad, but because of the need for commercial operation. The revival of LP in the past few years illustrates this point. If you have the opportunity to download some LP to 24bit/192k files and compare them, you will know the difference very well. If the amplifier and speakers are good enough, the comparison between LP and CD is as obvious as the comparison between CD and high-compression MP3.

2. In the digital part, if the clocks used are all generated by PLL, there will be no HIFI at all. The clock performance of PLL cannot be done well in civilian products because there are too many restrictions. The clock signal with too large jitter will cause the low frequency of the sound to be too fat, and it will not be able to achieve good performance. This is a conclusion I have reached through years of theoretical and practical comparisons.

3. The data stream of the digital turntable needs to be verified for its uniqueness. If the played file is consistent with the digital output and the recorded file, then it means that the data stream of this system is exactly the same. Decoding is ultimately a software job. The so-called hardware decoding is just a part of the work done by the hardware accelerator, not without software control. For example, the file reading before decoding must require software intervention and send to the corresponding decoder. The decoded signal must be moved from a certain address segment of the RAM to the I2S output through the software to complete the entire decoding and playback process.

4. HiFi is not as simple as you think. You can enjoy HiFi if you meet the above points. HiFi is actually a kind of leisure and a life attitude. There is an old saying that "when the granaries are full, people will know etiquette". If you worry about the future every day, you will not have the opportunity to enjoy HiFi. Therefore, looking at the HiFi industry, are there any famous reference machines from third world countries?

If a video player is used for HIFI purposes, at least 1-3 of the above points need to be solved. Some players on the market are changing the concept and throwing out the so-called theory of soft decoding and hard decoding, which is fundamentally untenable. After changing the concept, its attitude will inevitably affect the design concept. Even if 1-3 points can be achieved, it is difficult to be truly HIFI, because when rumors override the sound, the sound is polluted.

Video players are generally extremely optimized for video, adding a large number of video decoding accelerators, but ignoring the quality of sound playback. However, the intermittent requirements of video data are not as strict as those of sound. Therefore, most video players cannot process audio well. This part of the design is missing from the hardware, so it is difficult to make up for it through software in the end and achieve true HIFI. To give a very simple example, the passive clock signal of I2S determines what reference clock the system uses for output. If a clean clock cannot be introduced from the outside and the internal clock is used, the sound must be bad. As long as a little detail is not in place, HIFI will no longer exist.

Of course, if we discuss the above issues under harsh conditions, the HIFI circle is very small. Also, since most of the "audiophiles" are fake audiophiles, they are easily misled because they have never compared with reference-level equipment.

But please believe that there is a panacea for all diseases, but no one can truly cure them. A good system must be professionally built to reflect its advantages. Only by choosing the right system can you do a job well, rather than just any system that can be professional in everything.