: 8998.00 RMB

On December 28, 2019, Feiao finally released its M series, an Android intelligent lossless music player with flagship positioning-M15. After many years, after the X series, the M series finally has a corresponding flagship model. To tell the truth, the assistant has been looking forward to the release of X9 for the past two years. After all, X7MK2 is a normal change version of X7, not a newly designed flagship. Compared with the flagship of other brands, it is much less powerful. The release of M15 has finally been regarded as the heart knot of the assistant for many years. Feiao finally has a portable flagship rounded to 10,000 yuan. M15 comes standard with North American imported walnut wood wooden box, USB data cable, one quadrupole coaxial line and several pieces of paper.

design:

M15 adopts the arched design of Feiao's fifth-generation classical column shape that is comfortably held, and the fifth-generation classical column shape continues the appearance design of Feiao Q1 Mark II, K3, K5 Pro and other models. The M15 further adds a concave design on both sides. The side keys are concentrated on one side, and the sorting of the keys from top to bottom is logical. There are more physical lock switches and multi-function keys on both sides. Long pressing the multi-function keys will pop up "Add to My Favorite", "Random Next Play", "Delete Current Play", "Switch Filter", "Switch Equalizer", "Enter USB Decoding Mode", "Enter Bluetooth Decoding Mode" and other functions, the short press function is adjustable in the settings. The key stroke of the side keys is short and soft, and the play keys are not designed differently, and there are no blind spots. The relatively smooth blind exercise is carried out only by muscle reflex, and the cost is still slightly higher.

M15 screen uses Corning Gorilla Glass and a 5.15-inch full screen with an 18:9 ratio. It has a 86.0% high screen ratio, 16.7M color screen color, 312PPI high density display and 1440X720 high resolution. The actual display effect is really good, but it is still not as good as Abbaso's gorgeous Sharp screen. The back cover is made of PET coated carbon fiber texture and feels warm to the touch. The 2.5mm, 3.5mm, 4.4mm interfaces and analog potentiometer volume knobs distributed along the central axis at the top are dominated by all PO ports. The potentiometer has moderate damping. By reconstructing the ADC curve, the problem of low volume bias is effectively solved. The adjustment accuracy is very high. At the same time, the breathing light will flash. Of course, this light can also be turned off in the setting. At the bottom is TF Cato, which needs to be stuck. There is an etched inscription of "DUAL AK4499" of the same size symmetrically distributed, and the Type-C interface position is. Basically, it can be guessed that there was indeed an idea of double TF Cato in the early stage of M15 development, and the bottom circle is still left. If this design is kept, the assistant will definitely place an order on the spot, and the price of the 8998 is absolutely fragrant.

stacking:

M15 chip part adopts two AKM third-generation flagship DAC chip AK4499EQ, LSI audio special technology and current output architecture. Each chip contains four DAC channels, with theoretical S/N values as high as 140dB,THD + N as low as 124dB, supporting up to 768k sampling rate and native hard solution DSD512. The independent control chip XMOS XUF208 supports 768kHz/32bit, DSD512 and other highest standard sampling rates. USB decoding mode adopts professional USB decoding chip Xmos XUF208, supporting specifications up to 768kHz/32bit and DSD512. The Bluetooth chip adopts Qualcomm flagship model CSR8675, supports LDAC lossless two-way Bluetooth, supports Bluetooth 5.0, and supports SBC, aptX, aptX HD, LDAC, HWA and other formats for Bluetooth transmission. In addition to the above-mentioned formats, it also supports AAC, aptX LL, LDAC and other formats, but does not support HWA format reception.

M15 is equipped with two femtosecond crystal oscillators customized by Japanese NDK, with phase noise as low as-140dBc/Hz @ 1kHz offset. The clock phase-locked loop formed by the third generation FPGA clock algorithm of Feiao has extremely low jitter and provides excellent clock reference for DAC. The selected thin film resistor has the characteristics of 0.1% high precision, low temperature drift, low noise, etc. The special audio capacitor is 4 polymer low loss tantalum capacitors, 4 Panasonic stepless thin film capacitors and 8 small thin film capacitors. The power supply part uses 28 220uF low-loss polymer capacitors and 5 100uF high-voltage capacitors. The LPF part uses 4 independent 8 Panasonic metallized film capacitors. The PCB board adopts an 8-layer thickening and gold precipitation process. An independent shielding cover made of special absorbing material is added to the digital-analog circuit part, and customized thermally conductive silica gel, graphene and white copper heat sink are added to specific parts.

Regarding the actual shielding effect, the assistant did a simple but intuitive experiment. A mobile phone in a talking state was attached to the back of M15. During the whole process of switching on and hanging up, M15 did not show any "electric noise prompt", which was indeed a good enough shielding. The excellent heat conduction mechanism of M15 may indeed greatly reduce the heat generation of the fuselage. However, if M15 is used in earplug mode with high gain, charging and wireless network for a long time, the positive and negative temperatures can still reach around 35 ℃ (temperature gun data).

M15 consists of two high-precision, low-noise, low-temperature drift operational amplifiers newly introduced by Ti OPA2211 to form an LPF low-pass filter circuit, four OPA1612 to form an IV conversion, and each road uses OPA1622 as a secondary excitation circuit.

official mono circuit diagram

M15 applies the "active servo power supply" technology to the post-stage expansion. Its power supply capacity can be changed according to the system output settings, and the output power can be adjusted according to the impedance sensitivity. Under 32 Ω load, the single-ended PO output power is 490mW, and the balanced PO output power is as high as 800mW; Under 300 Ω load, the PO output power is 70mW, the balanced output power is as high as 280mW, and the peak power is as high as 25.5Vpp.

Official "Active Servo Power Supply" Circuit Diagram

SoC is still Exynos 7872, supporting 2.4G and 5G dual-frequency WiFi,3GB memory plus 64GB memory combination, and TFC card supporting 2TB expansion. At one time, the assistant thought that the maximum 2T expansion was already a standard function. Until I came into contact with a certain type of portability also developed on Android platform, this machine was still one of my main portability, but only supported 256G maximum expansion, which was very uncomfortable. The M15 battery uses a high energy density polymer lithium cobaltate battery of up to 7490mAh, customized FPC and Japanese SMK special battery connectors, and supports QC2.0, MTK PE, PD and other charging specifications.

software:

M15 may have the most orderly, kind-hearted, simple and easy-to-understand human-computer interaction. The completion of Feiao Music APP cannot be described as a perfect local audio playback software based on its complete functions, with emphasis on the degree of convenience. For example, the newly added one-click function to locate the current track is very practical.

also has some interesting functions. Compared with the first generation, the power consumption of the second generation global All to DSD is greatly reduced. Officials say that after the All To DSD function is turned on, the harmonics are evenly distributed, and the sound is comfortable, soft and audible. In addition, M15 also supports decoding MQA tracks in 8x mode. It also supports common streaming media functions, FiiO Link has also been retained, and the common double-click wake-up screen on mobile phones has also been lowered... Oh yes, there are also satellites with three-finger pull-down screenshots that have also fallen to the ground, which is very smooth.

sound:

M15 is definitely the best in Feiao's family barrel. Its quality, sense of music and so on have almost crushing advantages over the whole series of products in the past. M15's sound has an excellent sense of speed, clear shape and excellent line feeling. Such sound may sound slightly less relaxed and slightly tight. In addition, this kind of sound has a high probability that it will not be recognized by users who are used to listening to bile machines, but it is extremely suitable for users who play monitoring equipment all the year round. The following sound description is based on high gain, pure tone mode, short delay descent, big ear mode, turn off All To DSD.

M15 is more suitable for the interpretation of instrumental music than human voice. Its sharp transient performance makes M15 not soft even when playing back classical large-scale instrumental music. It can hold on to the big dynamics and scenes, and the sound field is open. It has a very reasonable depth and horizontal width; the layering of sound is also properly handled, and some plugs suitable for instrumental music can be used to obtain a strong on-the-spot experience. The voice of M15 is not bad, but less amazing than instrumental music. The voice of M15 is sweet enough, but the moist aspect is almost meaningful, slightly cold and hard, suitable for matching with looser or even soft vocal plugs. Of course, users who listen to female voices can also ignore this suggestion, and it is no problem to directly break hundreds of vocal plugs of this type.

M15 has a specific dyeing, there is an obvious deviation for the adjustment of sound, but it is not obvious or the direction is not too much deviation from the reduction... Here is one more word, X5 is tuned, you can't say that mineral water with sugar or transparent colorless has no taste, taste but not suitable for heavy taste users, that's all; In addition, some high distortion sound effects of X5 Ⅲ are really wrong, and the typical direction is wrong. The three-frequency energy distribution of M15 is slightly on the upper plate. The low frequency has a good texture, not much quantity, sufficient details, clear junction and fast speed. The mid-frequency vocal position and knot size are quite moderate, and the separation from the orchestration is enough. The vocal style mainly depends on the matching. The high-frequency details are more than the low-frequency, with sufficient overtones, and can show the metallic and air sense of instrumental music. It is vivid and bright but does not make the listener feel cold and hard.

M15 gives the assistant the feeling of a top bucket machine, which is frantically probing on the edge of the Pocket-HiFi. The idealized portable front end is nothing more than that.

Recommended population:

students who have high requirements for experience, sufficient budget and omnivorous food.

author:Mojia HiFi Garden04-16 18:47

website: https://weibo.com/ttarticle/p/show?id=2309404494408958476588