Jump to the first introduction of this Sony all-in-one product.
For ordinary smartphone users, you may not have heard of portable amplifiers. The function of the portable amplifier is that when some earphones need the output power of a large earphone hole, or you feel the need to tune between the mobile phone and the earphone, the portable amplifier will play a role, which is almost necessary for many fever-level portable information source players (including MP3, MD, CD players and smart phones).
Sony PHA- 1 not only has the function of portable amplifier, but also integrates computer USB sound card and digital-to-analog converter which can be used as iOS. The former should be understandable by ordinary people, that is, connecting the computer through USB cable instead of the built-in sound effect of the computer; As for the latter, to put it bluntly, when using the sound card of an iOS device, that is, skipping the built-in sound chip of iOS, the music is directly transmitted as a digital signal to PHA- 1 for decoding.
Why are you doing this? As far as digital audio is concerned, there are quite a few conditions to achieve good sound quality, but several main reasons are nothing more than the original sound source (which can be traced back to recording quality and mixing, etc.). ), the degree of file retention (such as the distortion of file compression), the ability of digital-to-analog conversion, the number of extended lines, and so on.
However, most mobile audio playback devices such as iOS take into account the power consumption and chip size in digital-to-analog conversion, and adopt a digital-to-analog conversion chip with relatively general quality but high power-saving integration, but it will also affect the sound quality to some extent.
Even if the improvement of sound quality is limited, don't forget that if the quality of the front end is poor, the defects will only be more obvious after amplification, and if the quality of the front end can be improved, it will also bring better feelings to the music listening experience; Due to the complexity of Apple's specification and authentication, there are very few devices that can directly convert iOS devices into digital analog, especially those that can be used at will. The author's own impression is that only Fostex, Venture Craft in Japan and ALO in the United States have such products.
Some of the above models have higher unit price, and some even only have simple digital-to-analog conversion function, and only one set of available magnification can be calculated with an earphone amplifier, so the price of Sony PHA- 1 is quite flat in other products with similar functions; However, cheap is not enough. As Sony's first portable all-in-one machine, Sony has also spent a lot of thought.
From the design point of view, PHA- 1 inevitably adopts the shape of Gall expansion of metal cigarette case, but the details are quite exquisite. In addition to the dark brown shell, the design of anti-collision fence is added at the front and back, especially the exposed volume knob is covered at the front, which can avoid the danger that the knob accidentally falls to the ground and directly damages the interior. In addition, the four corners of the fuselage protrude outward, and rubber strip is attached to the top and bottom of the fuselage, which also has its uses.
Because Sony has set the consumer groups of this product as portable music players and smart phone users, in the past, such users always tied players, mobile phones and portable amplifiers together. Because of sound insulation, this kind of portable amp will adopt a metal shell, but if there is no protective film between the player and the amp, it is easy to scratch the equipment; Sony simply added anti-slip tape to PHA- 1 and then attached two tapes to fix the player, which saved the player a lot of trouble.
The front of the fuselage has a volume knob, a 3.5 audio input hole and an earphone output hole. The red light above the knob is a charging prompt light, which will go out when it is fully charged, and the amp start light below will change from green light to red light when it is almost out of power. As for the micro USB slot with signal source lever, iOS digital input and USB input/charging behind it, remember to dial the lever to the corresponding signal input when using it, otherwise it will not work normally; There is a gain lever on the side, which is more suitable for headphones above 100 ohm after switching.
From the third page of Taiwan Province official website product introduction (please click here), you can see the complete interview content of the developer and the positioning of this product. It is worth noting that this portable amplifier uses Wolfson's high-end DAC chip WM874 1, and there is no higher signal-to-noise ratio than the big brother WM8740. However, its working efficiency at 5V is higher than that of WM874 1, and it is more suitable for portable equipment. In addition, the gentle trend of slightly intermediate frequency rendering is closer to the tonality of Sony's own MP3.
The analog loop adopts LM49860 with TI's emphasis on analysis and low distortion, and the amplifier is also TI's highly integrated amplifier chip TAP6 120. These two chips also belong to amplifier chips with a certain level of working efficiency at low voltage, and this combination can also expand the neutral characteristics of headphones in terms of power saving and sound. At 8 ohms, the output is about double 175mW, while at 300 ohms, the output is about 0.5 MW.
In addition, the circuit board adopts 6 layers of circuit board and 6μm copper foil, which can improve the conduction efficiency and reduce the noise. The internal wiring is also isolated from the analog circuit to reduce the mutual interference between the two transmissions. The power supply part PHA- 1 also abandons the popular all-digital charging management chip and adopts the traditional hardware architecture charging loop, which has less noise interference.
PHA- 1 is also a great article in the part of USB transmission for computers. Although Sony is doing PHA- 1 plug and play, the chip developed by Sony itself can not only reach the specification of 24bit/96KHz equivalent to WM8740, but also carry out so-called asynchronous transmission without driving. There are many USB external sound devices in the market that claim to provide asynchronous transmission, but most of them need to install drivers separately. Drivers can't provide asynchronous transfer when they don't support specific systems.
The standard USB transmission is to calibrate and synchronize the transmission clock between the computer and the USB playback device, but the disadvantage is that the calibration clock of the computer is not designed for audio, and its accuracy is higher than that of the audio clock, so it is easy to produce jitter and audio loss, and the general transmission will also transmit these losses to the USB device intact, which will reduce the sound quality.
What are the advantages of asynchronous transmission? Asynchronous transmission literally means that the transmitted digital audio signal is corrected by adding extra interpretation bits, and then transmitted to the buffer memory of the device, and then recovered by the calibration clock inside the USB playback device, so as to achieve high-quality sound with less consumption. Asynchronous transmission between the sender and the receiver is called asynchronous transmission because of unnecessary bits.
As for the iOS part, although Apple limited its digital audio output to 16bit/44. 1KHz, it could not fully utilize the high-specification chip of WM8740, but the highest specification of the chip is one thing, and the best working specification of the chip is another. Coupled with the advanced digital-to-analog conversion chip, even the same signal specifications can provide a better listening experience, but it is really only after listening.
This time, I borrowed headphones from my friends, including Sony MDR- 1, Sony XBA-4, Shure SE530, UE TF- 10, Beyerdynamatic DT880 250 ohm version and Sony MDR-Z 1000 as a comparison benchmark. Playback sources include iPad 2, Walkman Z 1000 and computers with Foobar 2000 software.
First, connect it to Z 1000 with the Walkman special Line Out attached to the package, and connect it to iPad 2 through the 3.5 analog terminal for pure amp test. In terms of output, it is not ideal to drive high-impedance headphones even if it is adjusted to high gain. I personally estimate that the limit is about 250 ohms, which is almost the limit that PHA- 1 can handle. Although headphones with high impedance, such as 600 ohm headphones, have sound, it is basically impossible to push them out horizontally and in space.
In fact, the tonality of PHA- 1 amp is not so obvious in Sony's traditional rich rendering taste, but more neutral, which should be related to the use of LM49820 for analog amplification and TAP6 120 for amp. Generally speaking, the original style of the front-end will be enlarged, and the adjustment of the front-end direction will not change much, which is considered as a fairly neutral amplifier design, but the low frequency is still very powerful and will not soften the low frequency of the front-end.
After connecting an iOS device, it's completely different. Because the digital-to-analog conversion is from WM8740 built in PHA, it is very different from the flat range of the original iPad 2. Moreover, the volume directly output by WM8740 is obviously at least 1/5 revolutions higher than that of PHA- 1 iPad 2 or Walkman. It can be seen that the volume of WM8740 in PHA- 1 is much higher than that of ordinary smart phones or MP3 players.
However, due to the addition of WM8740, the tonality of sound is much warmer than that of iPad 2, which makes the timbre of PHA- 1 warmer. On the whole, Sony Walkman has the characteristics of warmer tone and slightly smaller sound stage. However, compared with the Sony standard tuning output from Walkman Z 1000 headphone jack, it is still much more neutral. It can be said that iOS devices can emit tones similar to Sony Walkman.
But the greatest value is to improve the processing ability of iOS devices to MP3 files. Personally, I feel that 320k MP3 files are synchronized (after all, my main playback device is Walkman, so it is rarely converted into the lossless format of iOS). Although the original iPad 2 is more neutral in sound and has a wider range than Walkman Z 1000, the ability to restore details is seriously consumed.
With PHA- 1, we can find that the details are greatly improved and the details of the overall listening experience are more delicate, thanks to WM8740. Even if both of them are limited to 16Bit/44. 1KHz, high-order DAC chips can still play an advantage, but I still want to emphasize that if the innate audio files are not good, such as poor recording, you will listen to too much. ), may not be able to play the advantages of WM8740.
It is worth mentioning that PHA- 1 confirmed that the new iOS devices with Lightning connectors are compatible, and confirmed that the new generation of iPod Touch and iPad mini can run normally. However, only one stub of PHA- 1 is used for the 30-pin device in the package. Although the original Lightinig cable can be used directly, it is inevitably a little long.
Finally, when connected to a computer, it is regarded as a USB sound card. In the control group, the author has a USB external sound card, the other side is a self-owned brand, and there is a higher-order dual WM874 1 chip and TL7022 USB receiving chip. I must emphasize that this is a rather unfair war, because the author's products that use household power directly are far behind PHA- 1 which can only be powered by USB.
Similarly, under USB mode and Windows preset driver (DS driver of Foobar 2000), the desktop all-in-one machine can only rely on the advantage of low inherent noise of dual WM874 1, and the details of TL7022 of USB terminal are not obvious compared with PHA- 1 using USB asynchronous driver.
However, after changing to WASAPI driver, PHA- 1 did not significantly improve the sound quality because it avoided the inherent defects of general drivers, but at this time, the details of desktop DAC suddenly increased, and the overall analysis was much better than PHA- 1. However, as I emphasized earlier, this is the inherent advantage of desktop DAC. Because Sony's chip firmware adjustment is not synchronous, TL7022 is driven by universal USB sound, which can only be said to be a tragic result.
The style used in computer is close to that used in iPad 2, and it also belongs to neutral and warm tonality. If you use general pop music to record and compress digital music files, the quality is not much different from the digital input performance of iPad 2. However, in terms of the ability to handle high-quality recorded CDs and lossless compressed files, more details can be restored if a higher sampling output is turned on and used in conjunction with a computer.
When paired with a computer, PHA- 1 will cut off the power supply of the internal lithium battery and completely use the 5V power supply of USB. However, I am most worried about whether it will be disturbed by the unstable USB power supply. However, PHA- 1 seems to have done a good job of internal anti-interference, at least when the music stops playing completely, there will be no obvious current interference sound.
As far as compatibility is concerned, PHA- 1 is a Sony product when used as a sound card for iOS devices and PCs. It has high compatibility with MDR- 1, which can make up for the slightly depressed intermediate frequency of MDR- 1 and make MDR- 1 more vocal, but I personally prefer to drive MDR- 1 with low gain. In addition, it is also good to match with Sony's biased listening headphones such as MDR-7520, EX- 1000 and Z 1000.
However, when paired with Shure -SE530 or Sony's own CD-900ST headphones, which originally emphasized human voice, it will inevitably make the already prominent human voice more oppressed; In addition, the combination with Beyerdynamic DT880 is still useful, and it can also introduce deep and low frequencies that ordinary audio sources can't produce, but it is not so suitable if BeyerdDynamic DT 990 is more depressed.
As for the ability of the amp, the output is not too bad compared with the all-in-one machine with similar functions and specifications, but compared with the pure amp with similar price, PHA- 1 only removes the amp structure, and the performance of the driving force is not ideal except the tuning style. If the front-end used is already excellent, for example, the professional recording pen is a fever MP3 player, unless you like the characteristics of PHA- 1 amp, there is no need to use its digital input.
Of course, if there is no space restriction at all, you can plug in the household power supply at any time, and you don't need to take the ear extender out of the door. PHA- 1 can also buy a more expensive all-in-one machine; After all, being able to use household electricity is an innate advantage, and it is still difficult to compete with portable all-in-one machines that have battery life considerations and cannot be plugged in. However, readers must first make it clear that this is the inherent limitation of products developed on the premise of portability, and it is difficult to require the same performance under unequal conditions.
To put it simply, if the listening quality of an all-in-one product that is plugged in, has few functions and is larger than PHA- 1, I'm afraid the manufacturer should review their R&D personnel.
In addition, although PHA- 1 is much better than ordinary smart phones and players, there is still a gap in resolution compared with AKM AK4480 used by the more advanced Fostex HP-P 1. Moreover, according to Sony's setting, PHA- 1 is already an intermediary and terminal, so it no longer has the function of analogy with Line Out. I personally have friends who insist on stacking more than three layers with me (iPod+HP-p 1+ extra earphone expansion), so I can't accept the design of PHA- 1
Another troublesome part is power consumption. PHA- 1 Although it uses efficient amplifiers and analog amplification chips, even if it is used as a pure amplifier, it only has 10 hour of battery life, and only 5 hours when it is matched with iOS devices. Moreover, PHA- 1 can't receive additional power supply during operation, so it needs to be turned off and charged when the power is exhausted, which is a bit troublesome for some users who listen for a long time.
The knob of PHA- 1 is also integrated with the switch. In addition to the common portable sonic boom, the power supply will not be temporarily stopped because there is no signal input. On several occasions, the author forgot to turn off the switch when he acted as a computer sound card, resulting in almost no electricity when he woke up. He personally hopes that Sony can join this mechanism or make the power button independent. After all, turning the volume knob frequently for a long time will also cause loss, which may lead to poor contact or aging interference.
In addition, although the lead guard bar in front can be used to protect the volume knob, which is a very intimate design, when the earphone cable of the author is an L-shaped connector or the plug of the earphone is relatively large (some players will use a fever-level manual cable, and may use some high-quality hand-welded terminals. ), it is easy to get stuck in a ball. I wonder if Sony's exterior design engineering team can consider making a design that gives consideration to protection without making headphones too difficult to plug in?
Although I complain about some deficiencies in the design of PHA- 1, if you are an iOS device user, you will want to have a device that can be used in the office and taken away after work, and you will want to have a device that can listen to music on your laptop to improve the sound quality. PHA- 1 solves the functions of iOS, computer sound enhancement and headphone amplifier at the same time, and it is also one of the few models on the market that can meet the above three-in-one functions at the same time.
If you look at PHA- 1 with a single function, its price may be high, but if you want to meet two functions, the price of PHA- 1 is actually quite competitive. However, the collocation of this kind of audio equipment still depends on personal preference. After all, PHA- 1 does not reserve the adjustment OP for players to expand the chip's tuning ability. Before buying, it is recommended to find a place to listen and match yourself.