Decoding the headphone amp, a term that looks like hifi, is essentially a part of the "front end". If the electroacoustic system is to be divided according to the signal transmission, then it should be the turntable-> decoding-> headphone amplifier-> headphones. As a passive sound system, headphones require current to drive the speaker unit to vibrate and produce sound, and the front part is collectively referred to as the "front end". The turntable is mainly to pick up digital signals, the better the turntable, the more accurate the pickup, hifi circle uses "Jitter" (time base error) to measure the error rate.
As for the two parts of the decoding headphone amplifier, the digital signal is converted into an analog signal, and then buffered and amplified. If you want to say that the front-end part has the most impact on the sound quality, it is naturally decoding + headphone amplifier. Many HIFI old burners like to play "split", that is, the turntable, decoding and headphone amplifier are independent, the advantage is very simple, each link is independent power supply, to ensure that the power supply is pure and abundant; Secondly, the more space in the machine allows for higher quality components, so the sound quality of a split is theoretically better than that of a single unit. Nowadays, the era of fast food has made the split play more and more niche, especially in the field of portable HIFI, the "stacking music" game has become very rare, and it has been replaced by various forms of decoding headphone amplifiers.
(1) Bluetooth headphone amplifier, recommended model: FiiO BTR7,618 Price: 1099 yuan
Bluetooth headphone amplifier is a relatively mainstream decoding form of headphone amplifier in today's era. Especially for portable devices, one less cord means more convenience. The Bluetooth protocol is also the most compatible wireless transmission protocol, and various electronic devices such as mobile phones and tablets can be connected with one click. FiiO's BTR7 is a very competitive product at a price of 1,000 yuan.
This is a product released in 2022, for FiiO, a domestic first-tier manufacturer with a fast update speed, even in 2024, BTR7 is still the product with the highest positioning of BTR product line, which is enough to prove its excellent product strength. The machine is equipped with Qualcomm qcc5124 Bluetooth chip, Bluetooth protocol version is 5.1, and supports LDAC/aptX Adaptive high-definition Bluetooth encoding. In order to make the Bluetooth signal transmission more stable, FiiO specially designed a patented non-breaking metal bezel antenna. At the same time, it is also the first time that the THX AAA28 headphone amplifier is stuffed into the small body of the Bluetooth headphone amplifier to form a 4-channel fully balanced amplification circuit, and the balance port can reach up to 320mW@32 Ω output.
(2) "Little Tail", recommended model: Lebi W4 series, 618 price: W4 EX 1499 yuan, W4 2999 yuan
Compared with the Bluetooth headphone amplifier, the form of the small tail is relatively newer, and it is also the most popular portable decoding headphone amplifier form in recent years. In 2016, the iphone removed the 3.5mm headphone jack, in order to promote AirPods true wireless earbuds, and for players who pursue high sound quality, Apple does not support lossless Bluetooth protocol, with the introduction of high-resolution audio with high bit rate by Apple Music, users found that this kind of lossless can only be hardcoded by output to a wired small tail through Lightning or Type-C. So the little tail ushered in the opportunity of explosive growth.
The biggest advantage of this type of product is that it is "small". Since it does not have a battery, the small tail can be very small, containing only a low-power decoder chip and headphone amplifier circuitry. When it comes to the benchmark products of small tails, the W4 series of Lebi cannot be bypassed. Its earlier W2 series has won a lot of reputation in the high-end small tail market, and the new flagship series with lower power consumption and stronger performance directly pulls the dynamic and signal-to-noise ratio indicators to more than 130dB (W4 dynamic up to 134dB), of which the flagship W4 thrust is almost twice that of W2 (420mW@32 Ω), and the power consumption has been reduced by more than 40%; The sub-flagship W4 EX significantly reduces power consumption on the basis of W2 performance, while optimizing tuning. In terms of sound effects, the W4 series with built-in FPGA not only has a variety of scene mode sound effects, but also has specially tuned firmware for mainstream flagship headphones, which has high adaptability.
(3) "Big Tail", recommended model: Qianlong Sheng MUB1,618 Price: 2880 yuan
"Big tail" is a new form that has emerged in the past two years, the volume is between the standard size of portable decoding headphone amp and the small tail, the advantage is that the built-in battery is independently powered, compared with the small tail has a higher lower limit of sound quality, the disadvantage is that the volume and weight are not as light as the small tail. With the advent of the W4 series, the upper limit of the form of the small tail has been clearly visible, and the category is facing the situation of "no roll", and the big tail seems to have become the only "way to break the game". Qianlong Sheng MUB1 is such an existence.
With more volume, there is more room for use. MUB1 uses 4 CS43131 DAC+4 buf634, built-in 2500mAH lithium battery, a large number of audio electrolytic capacitors such as Panasonic electrolytic capacitors, as well as low internal resistance Würth alloy inductors, the analog power supply voltage under super gain reaches 16v, the thrust exceeds 1000mW@32 Ω, and the dynamic is also 132dB. In addition to the wired big tail mode of the strongest mode, the mub1 is also equipped with a CSR8675 Bluetooth 5.0 module, which supports wireless transmission of 24bit/96KHz specifications, and the performance of wireless audio is also good. In addition to the above standard functions, the MUB1 is also equipped with optical fiber and coaxial output, as well as car mode and other gameplay, just like a condensed version of the small country brick.
(4) Portable table, recommended: XD05PRO,618 price: 4880 yuan
The last category of portable decoding headphone amplifiers is the "Big Mac" general portable table. This form is better known for the Chord Hugo series and ifi audio's Diablo series. The XD05 series was originally just a standard-size portable decoder amp, and now in order to further improve the quality, it has also begun the "expansion road", all the way to the latest high-end model - XD05PRO.
As you can see from the name,05PRO is the most high-end style of the 05 series iteration so far,Compared with 05plus、05bal and other predecessors,The pro version can be said to be a collection of products that integrate all the technical features of the 05 series。 First of all, the thrust output is naturally strong, the pro version has been increased from the original 1000mW@32 Ω to 2000mW, which is quite rare in portable devices; Secondly, the replaceable op amp design of the 05 series has also become a combination of complete DAC + headphone amp module, among which DAC has AK4499EX version, ROHM BD34301EKV version and ES9039SPRO version, which is atmospheric and transparent, suitable for the performance of small strings; A delicate and sweet one, good at melodious vocals; Another grand restoration, suitable for large orchestration symphony, 3 combinations complement each other, in addition, it also supports the combination and matching of different earphone amplifier modules, playing hundreds of styles. For this decoder amp with great thrust and full playability, the only thing that needs to be adapted is the huge size and weight.