[pbui44]

You can post here about your impressions, comments, or general discussion of the Astell&Kern, or Astell and Kern, AK PA 10 portable headphone amplifier. The following was pulled from the official product discription page listing:

Portable Class-A Amplifier, AK PA10​

The First Class-A Portable AMP by Astell&Kern​

Astell&Kern has been researching and developing AMP technology to deliver the pure original sound of audio.
AK PA10 is the first AK model to introduce a Class-A AMP based on Astell&Kern’s know-how in AMP circuit design technology,
and it offers the natural and spacious analog sound of Class-A AMP enhanced further with our proprietary TERATON ALPHA technology.

Enjoy the pure analog sound of Astell&Kern with AK PA10's Current / Gain / Crossfeed options for digital audio players and source devices.
Application of Class-A AMP
Class-A Current Control (High/Mid/Low)
Gain Control (High Gain/Low Gain)
4.4mm True Balanced Input/Output Support
3.5mm Unbalanced Input/Output Support
Hardware Crossfeed Support
Unique SLOPE Design of Astell&Kern
Up to 12 Hours of Play Time
Power and Battery Indicator
USB Type-C Charger

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TERATON ALPHA, The Essence of A&K Audio Technologies

Great headphone AMPs generate true and pure sound reproduction, when not only a stable output is achieved, but also each and every part from power, noise, signal transition, circuit structures, etc., are carefully designed and implemented.
AK PA10 is small enough to be portable but operates seamlessly with a wide variety of headphones and IEMs, and is enhanced with the addition of TERATON ALPHA technology which is an AK Ultimate Sound Solution allowing for playback of ultra-high quality sound without any distortion.

TERATON ALPHA, engineered through many years of endless research, is Astell&Kern's unique technology that has been designed to produce audio playback that is as close to the original sound through effective power noise removal, efficient power management and unwavering amplification, and a fully converted audio output interface.
AK PA10 was developed as the sound solution of TERATON ALPHA, creating pure and intensive analog sounds.
Learn more about TERATON ALPHA >>​

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Distortion-Free Analog Sound of Class-A AMP​

Class-A AMPs offer the best linear output, providing soft, warm, and natural sounds by amplifying signals without distortions or defect. This characteristic makes it the most sought-after amplification method by music lovers, though it is considered impossible for portable audio devices as it requires high power consumption and design that is difficult to be realized for small devices.

AK PA10 integrates an Class-A AMP based on the unique circuit design technology of Astell&Kern, offering signature analog sounds.

With a unique circuit design from Astell&Kern that reduces power consumption and increases output while removing noise, AK PA10 is specifically designed to deliver the amazing sounds of an Class-A AMP anywhere and at any time.

AK PA10, the first portable Class-A AMP of Astell&Kern is here so that you can enjoy analog sounds through your portable devices.

Class-A Current Control - Intense and Spatial Sound of Analog AMP​

Headphone AMPs are not just designed to get the output required to operate headphones.
AK PA10 controls current to suit different headphones and IEMs reproducing a more intensive and spatial sound.

AK PA10 offers a three-stage control of Class-A AMP current, emphasizing the characteristic of Class-A AMP relative to the current value and creating a more intense sound.
Also, we addressed the concern of battery drain due to power consumption, the major reason why Class-A AMPs are not sued used for portable devices, by controlling the current value.

You can create sounds that suit the characteristics of headphones and IEMs through the three-stage current control option.
We hope you enjoy the textured and spatial sounds that AK PA10’s Class-A AMP can create.

*[Low] Default / [Mid] +50mA / [High] +100mA

Vivid Sound Output of Gain Control​

Sufficient AMP output is required to extract all the subtle nuances in music when played back through varying headphones and IEMs.

When connected to the balanced input, AK PA10 can support up to 6.2 Vrms output at high gain.
Choose the gain level that offers the best sound of the headphone and IEM that you use to enjoy crystal-clear sounds.
AK PA10 brings out the full potential that your audio device has to offer.

*[Low Gain] Unbalanced 2.1Vrms / Balanced 4.2Vrms (Condition No Load)
*[High Gain] Unbalanced 3.1Vrms / Balanced 6.2Vrms (Condition No Load)

4.4mm In/Out True Balanced Circuit Design​

Most portable headphone AMPs switch 3.5mm Unbalanced signals to 4.4mm Balanced signals or do not support a 4.4mm Balanced connection at all. Such input/output combinations limit users from using the pure balanced output of the source device resulting in loss of signal during the transition process.

Rare for a portable Class-A AMP, AK PA10 supports 4.4mm True Balanced input/output for high output and vivid audio.
It also supports 3.5mm unbalanced input/output ports so that you can use it with a wider variety of devices.

*Output is available for the same size as the input terminal. (Ports cannot be mixed for use e.g., 3.5→4.4 / 4.4→3.5)

AK Analog Sound Anywhere and at Any Time​

AK PA10 comes with a built-in 4,200mAh battery for 12 hours of continuous playback time without needing to connect it to a power source.
Enjoy the analog sound of Astell&Kern anywhere and at any time with AK PA10 which offers great portability and class leading playtime.

*Test Condition: Input 1Vrms, PA10 Volume 1 O’ Clock Position, Low Gain standard
*The proposed continuous play time is based on the company’s test result and it may vary by user setup and input/output setups.

LED battery status indication
PA10 displays remaining battery and battery charge status through its status LED.

[Power On] Turned on (Color changes according to the recharge status) White (70% or more) / Yellow (69%-30%) / Red (30% or less)
[Charging] Blue lights flashing (Regardless of power on/off) → Blue lights comes in when the charging is completed​

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Crossfeed Effect Completed by Hardware Circuit Design
As headphones isolate the left/right channels this can cause increased fatigue to a users ears during extended listening periods, and it offers limited spatial sound by comparison when listening to the same music from speakers.

Crossfeed mixes some of the signals from one channel and sends them to the opposite channel with a slight delay, creating a more central and natural sound, recreating sounds similar to that of listening via a speaker system, subsequently reducing listening fatigue.

AK PA10’s Crossfeed function is implemented exclusively by hardware circuit design, not by digital software, offering a more seamless and sophisticated crossfeed effect without degrading the original sound.

Turn on Crossfeed to experience the vivid, authentic and effortless sound this feature has to offer.

Perfect Circuit Design of High Output and Low Noise
Amplifying small signals to get greater outputs inevitably drives the noise level up.
However, AK PA10 introduces a high output design for the perfect operation of hard to drive headphones, using delicate current control, and a perfect circuit design that is the embodiment of the philosophy of Astell&Kern which continuously aims to deliver pure and refined audio without any noise.

AK PA10 incorporates our signature analog volume control that seamlessly delivers the sounds of the Class-A AMP. It also has a separate power supply IC per audio block that is divided into crossfeed, volume, AMP, etc., so that it can comfortably supply the optimal power required for each audio IC. This design eliminates the interfering ripple noise (rippling noise that occurs when power is turned on) of DC-DC power, thereby minimizing audio noises that may be amplified along with the audio.

In addition to this, our proprietary shield can technology is applied so that noises and electromagnetic waves do not affect the audio block and the design that physically separates unbalanced and balanced circuits completes the high-output and low-noise audio.

Audio Block

 

[bigbeans]

I am interested in this device, thinking of picking one up but impressions are scarce. The current switch is interesting as well.

 

[stellk3rn]

Well I have had one for a week....and blimey!

Setups tried

AK Kann Alpha plus Grado GR10 IEM, ZMF Vérité closed back, Grado RS1x.

Also Fiio M9 plus same headphones.

First things first. This is a step change device in my view. It made every combination significantly better and more enjoyable.

I don't do technical reviews, so forgive my descriptive style. My listening impression is that it just lets the music flow. Clean, silent, controlled. With a generally neutral balance and great extension. The trebles have a lovely light and natural flow, sub bass is present but never dominant. It doesn't make the sound 'powerful' but just seems natural. Detail emerges without ever sounding technical or synthetic. It just opens a window on the music. Reminded me of the first time I had a really good high end preamp in my home system.

What really surprised me was it worked some magic on the Fiio, which I never really rated. I always thought it a bit slow and unexciting but it seemed fuller and much more natural with the PA10. On the Kann Alpha with every headphone it boosted every facet of performance, taking it to a really high level. Sounded to me like each device and headphone was liberated to deliver it's best, and each felt like a more expensive and sophisticated version of the original, without changing character. The Kann/ZMF combi came close to the sound from my main home system with high end source and dedicated headphone amp (Trilogy 933). That is a real compliment.

Returning to the 'naked' DAPs each setup sounded thick, veiled and congested in comparison.

Couple more observations. My testing was done connecting the Kann and PA10 with the supplied 3.5mm link, I have a 4.4mm balanced one on the way. I tried the Current switch and any effect was subtle. Perhaps a little more dynamic but a touch 'shiny' in the high setting? Not sure it adds much, maybe it suits some genres. What did impress was the Crossfeed setting. Gives a lovely integrated soundstage without that slightly artificial left/right separation you can get with headphones sometimes.

Negatives? Well it is clearly a slabby clunky thing and hardly carry-around portable. An indicator of battery life might be nice. As for the sound, perhaps some will find the neutrality a bit 'dry'? I suspect however if your DAP/headphone combo is juicy and warm it will probably still sound like that, only better.

In conclusion, one of the best devices I have bought, especially at the price. Not apparently just a solution for hard-to-drive headphones or AK only. Go listen and tell me your thoughts!

Bruce

 

[muths66]

I really like how it pair with my rs6.I find it quite powerful and with gian to play around for sound preferences.I really happy for this new class A.

 

[JayF]

Any more impressions? I'm really interested in how it pairs with the SP3000 and if it's really much of an upgrade.

 

[muths66]

Any more impressions? I'm really interested in how it pairs with the SP3000 and if it's really much of an upgrade.

I guess pa10 and sp3000 share same current output. But rest different.

 

[pbui44]

I guess pa10 and sp3000 share same current output. But rest different.

Is the Low/High gain switch worth having with the Low/Medium/High current switch, like with planar-magnetic over-ears?

 

[stellk3rn]

The gain and current do different things. When I emailed A+K about how they worked etc this is what they replied;

With regards to the current and Gain switches:

Gain
This is to increase the output from the device. So depending if you're using IEMs or Headphones and their respective impedance you can adjust this accordingly. The higher the gain the more the output, so perfect for driving harder to drive high impedance headphones.

Current
This is a very subtle change and will be dependent on several factors which affect synergy including your source, and headphones/earphones. The higher the current the detail and reverberation the sound has. It brings out more texture and expressions in the music and is well suited to Jazz and Classical genres. Feel free to adjust this according to your setup and choose which setting you prefer.

From my experience this is pretty spot on. Personally I prefer the low Current setting, but it doesn't appear to alter the ability of the device to drive headphones. That is Gain.

Bruce

 

[muths66]

Is the Low/High gain switch worth having with the Low/Medium/High current switch, like with planar-magnetic over-ears?

I guess is good to have it.

 

[Edwin123bo]

Be really interesting to try different daps with this… don’t know which one would work best, honestly. Slightly frustrating that the in/outs cannot be mixed, as there are a couple daps I want to try that don’t have 4.4 lo.

 

[muths66]

Be really interesting to try different daps with this… don’t know which one would work best, honestly. Slightly frustrating that the in/outs cannot be mixed, as there are a couple daps I want to try that don’t have 4.4 lo.

Maybe u can ask astell what about using an adapter like 4.4-2.5.

 

[tfenton02]

Any more impressions? I'm really interested in how it pairs with the SP3000 and if it's really much of an upgrade.

I received the PA10 a few days and have been swapping Daps to get some initial impressions > SP3000, SP2000cu, Sony ZX707. If I get a noticeable improvement (doesn't have to be transformative) in my listening experience I'm fine with paying more to get it. (listening was paired with Noble KK, Code23 cable)

SONY ZX707: Primarily used out of home, air travel, pocket listening. With PA10, it transforms the Sony into a TOTL listening experience. Soundstage expands massively, instruments are more separated, more layering, AK house sound is introduced but retains some of the warmth with Sony.

SP2K: Wow. I wasn't expecting much, but there is a noticeable improvement to an already great DAP. The soundstage expands in every direction, every note carries more weight, and the depth of the low end is deep and richly textured. They layering is top notch. The soundstage doesn't approach the SP3K level, but it's better in every way. There is also a little more smoothness/richness in the notes. With the Noble KK, the bass is just absolutely massive, visceral punch in the throat kind of experience.

SP3K: The soundstage gives me an out of body experience on the SP3K. Imagine a completely black, infinite space where the music seems to magically float in that space and you have this, hard to describe, truly 3D listening experience. With the PA10, the soundstage is retained, you have a little more smoothness, and each note has more authority.
The PA10 is one of my better acquisitions in the past year. Glad I pulled the trigger. (design-wise, AK hit another home run, albeit more minimalistic but it's a beauty.

Cons so far? First, it doesn't come with a 4.4mm cable, so you're SOL if your IEMs don't have one. I have one on order now. Second, no known case in the market that I can find.

 

[muths66]

I received the PA10 a few days and have been swapping Daps to get some initial impressions > SP3000, SP2000cu, Sony ZX707. If I get a noticeable improvement (doesn't have to be transformative) in my listening experience I'm fine with paying more to get it. (listening was paired with Noble KK, Code23 cable)

SONY ZX707: Primarily used out of home, air travel, pocket listening. With PA10, it transforms the Sony into a TOTL listening experience. Soundstage expands massively, instruments are more separated, more layering, AK house sound is introduced but retains some of the warmth with Sony.

SP2K: Wow. I wasn't expecting much, but there is a noticeable improvement to an already great DAP. The soundstage expands in every direction, every note carries more weight, and the depth of the low end is deep and richly textured. They layering is top notch. The soundstage doesn't approach the SP3K level, but it's better in every way. There is also a little more smoothness/richness in the notes. With the Noble KK, the bass is just absolutely massive, visceral punch in the throat kind of experience.

SP3K: The soundstage gives me an out of body experience on the SP3K. Imagine a completely black, infinite space where the music seems to magically float in that space and you have this, hard to describe, truly 3D listening experience. With the PA10, the soundstage is retained, you have a little more smoothness, and each note has more authority.
The PA10 is one of my better acquisitions in the past year. Glad I pulled the trigger. (design-wise, AK hit another home run, albeit more minimalistic but it's a beauty.

Cons so far? First, it doesn't come with a 4.4mm cable, so you're SOL if your IEMs don't have one. I have one on order now. Second, no known case in the market that I can find.

I only manage find one shop in taobao custom make the case for pa10. Waiting for seller show me then i order.

 

[Tomm11]

So A&K's $500 amplifier is better than the amplifier contained within the $3600 SP3000 ...

 

[Edric Li]

Would love to hear how PA10 compares to other portable amps in the ~$500 price bracket.