Recently, FiiO released the new AMP: KA13. Before this, the KA series already had KA1/KA2/KA3/KA5, and now with the addition of KA13, there are a total of 5 models.
Among them, we noticed that although the serial number of KA3 is 3, it is FiiO’s first generation product. Although it is still on sale, its life cycle is relatively long. Judging from the size and basic I/O configuration of the new model, there is probably some kind of iterative replacement. This speculation has been officially confirmed by FiiO: KA13 is an upgraded model of KA3.
Update: FiiO KA13 is now available for $69.99 on Geekwills.
AudioTOP immediately got two samples of KA13, one black and one silver. This article contains a comprehensive review and a disassembly report. We will use one for disassembly and archiving, and the other must be sent out completely after the review is completed, so I wish you all good luck. Let’s first take a look at the changes in KA13 compared to the previous generation.
The old KA3 has dual headphone jacks, but no buttons, and of course the body UI is missing. Its structure is relatively simple, with a square barrel-shaped shell and two end caps for sealing. This kind of design is more convenient for manufacturing and assembly. FiiO’s previous small tails all had a similar structure.
FiiO KA13 adopts a new structure and appearance design language. Its casing is cut and carved using CNC technology, the motherboard is placed from the back, and then closed with a piece of glass back panel.
The weight of the new and old models is basically the same, and the length is almost the same, but the new model is flatter, which means it is thinner. As for the reason for the thinning, sharp-eyed friends should figure it out from the picture above. The axes of the two headphone jacks of KA13 are on the same height line, while the old FiiO KA3 has one higher and one lower—on the market Most little tails are so crooked.
I can tell you clearly: the current obstacle that limits the further thinning of the small tail comes from the 4.4mm headphone socket. As for why FiiO KA13 can achieve the same height and become thinner, further analysis will be done during the disassembly process.
There is an asymmetrical pentagonal glass window on the front of FiiO KA13, which not only provides a perspective effect, but also contributes sufficient recognition together with the “X” cutting line.
The appearance style changes greatly. Putting the old and new models together makes it impossible to see any similarity or inheritance of elements between the two. It can be said that even my own mother cannot recognize them. In terms of details, the fit of the glass is flawless, the logo and slogan have changed from flat laser engraving to CNC engraving, giving a strong three-dimensional effect. The structure of KA13 is more complex and the craftsmanship is more refined. It can be touched even when the lights are turned off.
The old KA3 did not have any controls. The FiiO KA13 adds a seesaw button. Press it briefly to adjust the volume, and press it long to switch songs. In addition to this there is a “D. mode” switch. I thought D meant Dynamic, but the official explanation is more ruthless: Desktop, which means below or above. We’re not done with D. mode yet, let’s take a look at the test.
(Note: AudioTOP adopts relatively stringent test conditions. In the separation test, the level amplitude is limited and the LPF frequency is set at 90k, so the measured separation value is lower than the official data, which is reasonable and common)
During the test session, what was unexpected was the ultimate power output capability of FiiO KA13. AudioTOP has tested a large number of small-tail decoders before. Judging from the experience gained from past tests, the power ceilings of single-ended and balanced ports of small-tail products are respectively 130mW and 250mW.
As for why this is the case, the reason is that the little tail itself does not contain a battery, and the power supply is obtained from the mobile phone through the USB port and OTG cable. The mobile phone itself also has battery life concerns, so the power supply to the outside world can only be limited. Android phones are relatively better, while Apple phones are stingier. Usually, when the small tail is plugged into an Android phone, the maximum output power can basically reach the nominal value. When testing the balance port on an Apple mobile phone, it is very common to encounter a sudden waveform collapse.
So will plugging the little tail into the desktop computer improve it? Yes, but usually the degree of improvement is limited. On the one hand, this is because the computer USB port actually has current-limiting protection, and on the other hand, the power chip and headphone amplifier chip inside the Little Tail will also reach their own power limit.
In this KA13 output power test, the 3.5mm single port reached 168mW, and the 4.4mm balanced port reached 567mW (see test screenshot), both breaking historical records. Among them, the breakthrough of the balance port is very large. The highest record we measured before came from iBasso’s DC06, whose maximum balanced port power was 359mW.
The best ultimate power of KA13 is indeed measured on the USB port of a desktop computer, but there are two things to note here: first, other small tails cannot reach this high even if they are plugged into a computer; second, even if KA13 is connected to a mobile phone, Even the output power of Apple mobile phones is already quite high.
D. When the mode switch is turned to ON, the output level will increase by 6 dB, which in human terms means that the output voltage amplitude will double. So is D. mode the reason why KA13’s power limit breaks? Not at all. I’ve seen small tails with similar boost switches before, but I didn’t measure high power.
For the listening test, one track is from Apple Music, and the other three are from Sony HR selections. The reference comparison models are mainly KA3; headphones: FX15 and IE900; mobile phones: iPhone 11, vivo X90 Pro+.
“Linshicheng Pipa”: Most of the instruments with excellent performance are sonorous, resolute and sparkling in the first track. KA13’s interpretation of this is spot on, which shows that it has good imaging and burst power. On this track, the KA13 performs better than the KA3.
The Love Changing Ball of “Xiaoyaoyou”: The rhythm of the cassette era, the drum sound is crisp and clear. In this track, KA13 and KA3 are evenly matched, both are quite powerful.
Dosukoi Engine of “The Lonely Gourmet”: Roaring output accompanied by drum beats. In this track, the KA13 has a clearer sense of lines in the bass area and is more emotionally charged.
Track 1 of “Paganini’s 24 Caprices”. Sharp, tense, astringent feeling. In addition to these, KA13 can also exhibit good cabinet resonance. The mid- and high-frequency bands of KA3 are slightly more eye-catching, so the cabinet resonance is relatively less obvious. I won’t draw a conclusion about which one is better here, I just say that there is a difference between the two.
It’s time for disassembly. The first step is to heat it properly and then use a suction cup to lift the glass cover.
A look at the back of the motherboard. You can see two screws that secure the motherboard.
Remove the screws and remove the motherboard.
On the main component side, the key components on the audio link are all in this area. The chip of character 9312 is the USB interface SA9312L; one DAC chip CS43131 for each channel; and one headphone amp chip SGM8262 for each channel. Judging from the component configuration, KA13 is a full-link balanced architecture.
For comparison, the DAC of the previous generation KA3 is an ES9038Q2M; the USB interface is CT7601; and the amp chip is 6863D. This is the mainstream small-tail circuit architecture in the past two or three years.
Keycaps and dust shields on the sides. In places that cannot be seen inside the cavity, the detail processing is still meticulous.
The small blue square presses the two amps. According to my understanding, it should be a cooling pad.
Let’s look at the headphone jack. The 4.4mm socket adopts a new thin model, and its height is almost the same as the 3.5mm socket.
At the same time, the motherboard was broken and installed under the sun. Through the above efforts, KA13 was able to successfully slim down 1.5mm.
Contrast hurts. Now everyone should understand why the tail of many dual headphone jacks is not only thick, but also the two holes are higher and lower.
In terms of accessories, it comes standard with one Lightning and Type C OTG cable, as well as a USB A adapter, making it easy to connect to all three mainstream platforms. In addition, I want to say one more thing about this Lightning OTG line. When using it, you can use your finger to measure the temperature for comparison. The plug of this line is cold, while other Lightning plugs are hot.
During the test, it was found that using iP11 as the host computer and using other cables, the balanced port peaked at 170mW. When using this cable, the measured power limit was 337mW. Its quality is very rare and it is not for sale. Since it is an ordinary-looking distribution cable that disappears into the online group after being dropped into a drawer, I recommend that users label it to avoid confusion.
The above is our review and teardown report of KA13. Overall, this update is not a minor fix, but a completely new build. New cavity structure, circuit architecture, manufacturing process, and visual language. The UI control keys are created from scratch, and the thin body is cleverly achieved.
In terms of performance, the output power of KA13 greatly surpasses the old KA3 and has become a benchmark in its category. Although power output is not everything about performance and sound quality, it does affect the sense of energy and entity. For small tail decoder products, this is the breakthrough and direction of progress.
FiiO KA13 is now available for $69.99 on Geekwills.
