First of all, I am a non-professional person. I have never studied a similar major when I was a student. I am a student of pure liberal arts. I just like tossing, so I have continuously played with tape drives, MD, CD, DAT, and then I play with the desktop. , Class A Transistors, Class A and B Transistors, Digital Amplifiers, Single-Ended Tubes, Tube Preamps, Tube Amps, DACs, Earth Cannon Boxes, Domestic Boxes, European Boxes... Many things tossed, but nothing was learned know how. Now if I want to hold a soldering iron, I can weld it, but if I want to say a principle, I'm sorry, I don't understand.
I am not brain-delivered, nor is it a wire-line party. I don't like to change fuses, nor do I like to add graphite feet, and I ignore it. For hydroelectricity and wind power, I have not studied anything. My family does not know what electricity is used.
So in this post, I can neither make any theoretical arguments nor draw any conclusions from the principles. It's just fun, try it, compare it.
So if there is anything wrong, you also hope that the gods will tap the bricks.
First introduce the four devices that need PK - Innovation E5, this thing is the most expensive PK, 1000 ah, heart hurts.
BOSE Bluetooth adapter, it is said that a certain batch of garbage that was punched and scrapped from the Internet was picked up and sold to all major forums, 150 pieces. It was heart-paining, but it was said that there were more than 300 new treasures.
Apple A1084, this stuff is purely non-jobless, originally a wireless router, well, you as a wireless router, but also get a 3.5 interface, there is an interface, Nima actually also with digital output.
AIR MUSIC, this stuff has been sold for a few years, has been tepid, and only occasionally after buying it.
All four devices have one thing in common: First, they can all be wirelessly connected to the mobile phone. Both the A1084 and AIR MUSIC are connected to the mobile phone via WIFI. Both the innovative E5 and BOSE are connected to the mobile phone via Bluetooth. Second, there are digital output interfaces that can be fiber-optic connected to the DAC.
This year, almost all of the people who play vinyl are really old people. It is all rich middle-aged people who play digital broadcasts. I like 30-year-old young people still like the phone and IPAD, but the phone is also good IPAD worth mentioning, the sound quality is really unsatisfactory ah (can not afford to buy a step-hi-step HIFI phone), and then, the family is still very unlucky, there is a set of desktop equipment, Therefore, how to effectively connect a mobile device to a desktop device can be troublesome. So why do I buy these wireless gadgets? That's why.
Then introduce the final carrier of this PK.
Source - IPAD MINI 2 16G Edition.
The DAC came from a big god of HIFIDIY. It is said that he accidentally discovered a group of PCBs. He took a study. Oh, yes. So he gave the PCBs a backplane, got a power supply, got a box, and sold several Hundreds of thousands of units, the core of this DAC is the AD1852, a decent decoder chip.
Because this DAC has only coaxial input, but I have only one CD for coaxial output, the other is the optical fiber output, so I bought the upconverter of Taiwan Music State back, this thing is not bad, there is coaxial, optical fiber , BNC three input ports, as well as coaxial, fiber optic, BNC three output ports, which means that as long as the audio source of these three interfaces, can connect, and then can also be converted to the output interface I want, more The important thing is that it can output the received digital signal after upsampling, 44.1K, 48K, 88.2K, 96K, 176.4K, 192K. Unfortunately, my DAC can only receive up to 96K.
The amplifier is a little bit old ONIX OA-80, this machine basically can not find any parameters, but ONIX is a bit well-known audio brand. The predecessor is an X-PRE from music fax, a famous tube preamp, one of the famous piglets. The speakers are from QUick by QLN, a Swedish native, two-way floor-to-cease box with a light box, but with typical European sounds and a pair of boxes that I had for ten years.
PK's several songs, WAV lossless format, pay more attention than MP3.
Here's a brief talk about two different transmission methods:
Bluetooth transmission is currently the most widely used. A2DP (Advanced Audio Distribution Profile) is a sub-protocol of Bluetooth. Bluetooth headsets, speakers, etc. are all used to transmit audio data streams through this protocol. The data bandwidth that can be used by Bluetooth audio is also defined by this protocol. After examining the data, it can be known that the Bluetooth 2.0/2.1 +EDR connection rate is 3 Mbit/s and the actual available data transmission rate is 2.1 Mbit/s. Bluetooth 3.0 introduces new features for high-speed data transmission, with a maximum data transfer rate of 24 Mbit/s. The latest Bluetooth 4.0 is a hybrid that includes three subsets of traditional Bluetooth, high-speed Bluetooth, and low-power Bluetooth, which is equivalent to 2.1 plus 3.0. +HS and Bluetooth low energy. In Bluetooth transmission, if you want to achieve a 1411.2kbit/s bandwidth for CD sound quality, obviously A2DP cannot tolerate it, so the audio data needs to be compressed. At the same bit rate, the sound quality of different encoding formats is different. A2DP requires that sub-band coding (SBC) must be supported, and MP3, AAC, and ATRAC are optional encodings. Other proprietary encoding formats may also be used. The latest APT-X is CSR's proprietary encoding format with a compression ratio of 4:1 (approximately 352 kbit/s) and claims to achieve CD quality. The general steps of Bluetooth's entire transmission process are as follows. Take MP3 files, it will undergo two decoding and one encoding process (MP3 → PCM → AAC/SBC/apt-X → PCM), since MP3 itself is lossy Compression, followed by a lossy code, the impact on sound quality is self-evident. Even lossless encoding will experience a lossy encoding throughout the transmission.
WiFi transmission, for now, the bandwidth of the transmission audio signal is basically sufficient, the actual speed in the LAN can reach 32Mbps, this rate can completely transmit lossless audio data. The more common solution is to use the DLNA protocol, AirPlay protocol, and Qplay protocol to transmit. Presumably, the sound quality of the transmission process is not lost. It only depends on the fiber output quality of the receiving device.
In simple terms, Bluetooth transmission is a process of retransmitting transmission and reception. The DLNA protocol in WIFI transmission is the process of source code transmission, which may be more limited by the capabilities of the device hardware. AirPlay protocol is also a process of retransmitting the code to transmit and receive. However, since the bandwidth is larger, it is estimated to be a lossless codec process.
This is roughly the same in theory, but what is the actual situation? Depends on several aspects: the interference in the wireless transmission process, the circuit design of the equipment, the quality of the components...
After teardown or check the information, we can know that the decoder chip used by these four devices are: Apple's A1084 uses PCM2705, AIRMUSIC uses WM8904, innovation E5 uses CS4398, BOSE does not seem to have a separate The decoding chip may be integrated in that Bluetooth chip. Of course, because this test did not use the analog output part of these four devices, it has nothing to do with the decoding chip used by the device.
Here are the pictures for the same song: The first is AIR MUSIC:
As you can see, AIR MUSIC outputs a 44.1K signal.
Then came the Apple A1084, because I had modified the name of the machine, so it looks like this:
You can see that the same output is a 44.1K signal.
Here is the innovation E5:
The innovative E5 output is a 48K signal:
Here is the BOSE Bluetooth adapter:
The BOSE outputs a 44.1K signal:
The following PK results, based solely on my personal love of listening, only represent my point of view, I do not like to spray, thank you -
In fact, these gadgets, in addition to innovation E5 just arrived a few days, the other is spent a relatively long time, and some have been accompanied for at least 4 or 5 years, so for these few gadgets sound , I am more familiar with, originally did not intend to do a PK, a few days ago, in Aunt Zhang's home recommended Aere and Bluetooth device posts, I mentioned the Bluetooth and WIFI devices, there are valuable friends say why not do PK, so this post was only available.
In the habit of listening to music, many of the first choices to play HIFI is a saliva song, so Tong Li and Tsai Chin became a familiar type for many people. Then there was Zhao Peng, a vocal subwoofer, and a series of fever saliva. No denying, I also listened to these, but apart from these, I also heard more about pop music. I recently liked the big brother of the ball. Sometimes I listened to pure music, guitar, piano, saxophone, erhu, of course. Just listen to it, and I can't tell you exactly what I have. I just listen to it.
The PK used a saliva song, used rock, used pop music, folk songs...
In actual listening, BOSE sounds straightforward. It is pure boiled water. To be honest, from my personal hobby, I don't like this. Just like the previous Apple player, it's bland. Even my DACs, amplifiers, preamps, and speakers are all European-style sounds and can't be modified to make BOSE more appealing, and it's clear that the device is distorted. Innovation E5, low-frequency a little elastic, but always feel too much modification, like SONY's friends always like SONY's tuning style, but innovation has Japanese tuning, lack of sense seems to MSG a bit more, but this kind of sound comparison Cheating, especially when listening to you, is not tired. Apple A1084, without exception, is Apple's usual style. If BOSE is boiled water, Apple is pure water. AIRMUSIC, I have no disguised my favorite of this gadget. If I can perfect it better, I don’t think I will refuse to use it for a long time. Unfortunately, I’m sorry that neither Android nor IOS supports it. Catton is often seen in the sound, but it is worth listening to when working normally.
So in my mind, just from the sound quality and personal tone preferences, I think AIR MUSIC> Innovation E5> Apple A1084> BOSE Bluetooth adapter.
In fact, in addition to the wireless connection, I prefer to use the IPAD to connect to the innovative E5 via the USB HOST over the past few days. The wired mode is better than the wireless mode in sound quality. The computer is also sometimes connected to the innovative E5 via USB. The E5 is an external sound card and is of better quality than the computer sound card or the audio decoded after being connected to the display via the DP. As a computer's external sound card, in fact, USB asynchronous transmission is very advantageous, but there is still a gap between USB and 1394, I would like to try to use the innovative E5 and my other TC K8 for comparison. 
For E5, I also made a special USB HUB.
Well, the above is purely nonsense. Once again, if there are any mistakes, please correct them. Do not like not to spray.
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