Astell & Kern Kann Ultra DAP Review

[Henry53]

Hi

Astrell & Kern is a HEA (High End Audio) company, as such, it features all their pretenses and poor to middle of the road objective performance. Back in the days before ASR, they could boast superiority while the HEA ecosystem, the magazines, the headphones websites, etc would sing their paeans.

No longer. ASR is here to stay, this DAP, can easily be bested by even more portable combination of a smartphone IOS or Android with a good dongle, (there exist a plethora, many were reviewed here and recommended) at perhaps 1/5 of its price in everything that matters .. including portability .... but if you have the dough and want to show your audiophile cred, this DAP, plus similarly expensive but poorly performing IEM, and cables from Synergistic Research such as this $695 (!!!!) model, would be the ticket. ...

I voted poor...

Peace.

Have you listened?

 

[Henry53]

Reserved for @RickS to kindly post the specs.

View attachment 444595

More specs are available here.

So we seem to have an issue on maximum gain, on balanced output for 300 omh impedance load! Is this actually realistic!

 

[FrantzM]

Have you listened?

Do I need to ?

 

[Henry53]

Do I need to ?

I believe that audio equipment is designed and built to be listened too, is it not. Surely testing should correlate to that. This test reminds me of the aircraft safety tests that only ever killed or injured anyone during tests, i.e no incident ever occurred where the tested parameters had actually taken place. Testing a DAP at full load (highest and lowest impedance) on maximum power ( Super High) and maximum volume, when instructions say not to do that! This is rather like performing a test driving on the wrong side of the road, when drunk at maximum speed and determining the car, upon crashing is unsafe?

 

[RandomEar]

I believe that audio equipment is designed and built to be listened too, is it not. Surely testing should correlate to that.

And, as explained multiple times already, it does. I do not know where the confusion is coming from, here.

This test reminds me of the aircraft safety tests that only ever killed or injured anyone during tests, i.e no incident ever occurred where the tested parameters had actually taken place.

I do not know what is vaguely being referenced here, but at best, this remark sounds uninformed.

Testing a DAP at full load (highest and lowest impedance) on maximum power ( Super High) and maximum volume, when instructions say not to do that! This is rather like performing a test driving on the wrong side of the road, when drunk at maximum speed and determining the car, upon crashing is unsafe?

But - again - as the graphs clearly show, this is not the only region where problems occur. Noise is elevated at low power in high and very high gain. Many heaphones will use that level of power (<1 mW) at very reasonable listening volumes. And for low impedance headphones, peak power is pretty weak when compared to competing products. For 1500 f*cking dollars, none of these issues should exist.

This device has significant engieering flaws that will impact the listening - not on all headphones, but I would assume for example on some Dan Clark models. So high-end headphones people are likely to combine with a supposedly high-end DAP like this.

 

[Henry53]

And, as explained multiple times already, it does. I do not know where the confusion is coming from, here.


I do not know what is vaguely being referenced here, but at best, this remark sounds uninformed.


But - again - as the graphs clearly show, this is not the only region where problems occur. Noise is elevated at low power in high and very high gain. Many heaphones will use that level of power (<1 mW) at very reasonable listening volumes. And for low impedance headphones, peak power is pretty weak when compared to competing products. For 1500 f*cking dollars, none of these issues should exist.

This device has significant engieering flaws that will impact the listening - not on all headphones, but I would assume for example on some Dan Clark models. So high-end headphones people are likely to combine with a supposedly high-end DAP like this.

Again, no I'm not uniformed re aircraft crashes during testing, thanks. However can you define what noise is? Noise is only noise if you can hear it!

 

[RandomEar]

However can you define what noise is? Noise is only noise if you can hear it!

Certainly a riveting discovery! This doesn't feel like a productive discussion anymore to me. Have a good day.

 

[Henry53]

This device is intended for headphone listening. Room doesn't factor in the equation. The headphone output clips severely causing massive audible problem for lower impedance headphones. So i suggest you park your justification elsewhere.

Does anyone report hearing this?

 

[Henry53]

Some people with some headphones will likely be able to hear the defects. Those people are informed by the review that this device is not for them.

Everyone else is informed that there are technically better devices at lower cost - so absent other reasons (aesthetics/features etc) then this device is probably not for them either. Why should I take the risk of buying something that I might find out later has - under some circumstances - audible defects.

Especially at the cost of a top end iPhone - which certainly has technically better audio performance.

However the readings are taken using low impedance loads, at the highest power level, with balanced connections something you are advised not to do.

 

[Somafunk]

you're getting desperate now....

 

[Henry53]

you're getting desperate now....

But that is how the reading were taken! Quote: you can use low-impedance balanced headphones on the Astell & Kern Kann Ultra, but you must start on Low Gain to avoid blowing out your ears or damaging sensitive gear. The 4.4mm balanced output pumps out massive voltage (up to 16Vrms on Super Gain), which is extreme for low-impedance gear. Would you use 99dB sensitivity speakers rated at 2 ohms with a 500 watt balanced amplifier and then be surprised they clip?

 

[RandomEar]

But that is how the reading were taken! Quote: you can use low-impedance balanced headphones on the Astell & Kern Kann Ultra, but you must start on Low Gain to avoid blowing out your ears or damaging sensitive gear. The 4.4mm balanced output pumps out massive voltage (up to 16Vrms on Super Gain), which is extreme for low-impedance gear. Would you use 99dB sensitivity speakers rated at 2 ohms with a 500 watt balanced amplifier and then be surprised they clip?

You continue to ask the same questions in a different format again and again and ignore the explanations given by fellow members. I'll try one last time before this this is going onto my ignore list:

You deperately try to justify a device with some clear engineering flaws. For low impedance headphones, the measurements show that it doesn't matter which gain you use: You're voltage-limited and will clip around 40±5 mW. Read. The. Graphs. Headphones where this will be limiting, because you're very likely to reach the clipping point listening around mid 70s dB_RMS, which means short peaks to the mid 90s will be common: [1, 2, 3, 4]. For more examples of problematic headphones, feel free to search the review index yourself.

Why would anyone aiming to get a high end DAP accept such compromises? If you want to drive $50 IEMs, this will work fine. But that's not what you buy a $1500 DAP for, any $20 dongle can handle those. It's meant to be used with high end headphones. Which can be challenging to drive. Which this DAP can't cope with.

 

[Henry53]

You continue to ask the same questions in a different format again and again and ignore the explanations given by fellow members. I'll try one last time before this this is going onto my ignore list:

You deperately try to justify a device with some clear engineering flaws. For low impedance headphones, the measurements show that it doesn't matter which gain you use: You're voltage-limited and will clip around 40±5 mW. Read. The. Graphs. Headphones where this will be limiting, because you're very likely to reach the clipping point listening around mid 70s dB_RMS, which means short peaks to the mid 90s will be common: [1, 2, 3, 4]. For more examples of problematic headphones, feel free to search the review index yourself.

Why would anyone aiming to get a high end DAP accept such compromises? If you want to drive $50 IEMs, this will work fine. But that's not what you buy a $1500 DAP for, any $20 dongle can handle those. It's meant to be used with high end headphones. Which can be challenging to drive. Which this DAP can't cope with.

So again you agree that this supposed major problem makes no difference when listening to actual music thriugh actual headphones.

 

[Somafunk]

Please god….make it stop……

 

[Henry53]

Please god….make it stop……

It has thanks you have proven my exact point. No one has actually ever heard an issue.

 

[Henry53]

Please god….make it stop……

As a devoted audiophile for over 50 years and a forensic engineer for over 30 I find either end of this topic a mixture of bewilderment and amusement. On one hand we have people who claim to hear significant improvement by buying a $14000 cable over one costing only $5000. On the other people stating that a 0.001% difference in some measurement of distortion is audible on headphones that are lucky to keep their distortion below 1%. So no I’m afraid these measurements, the supposed results of which should stop you buying equipment in which no one has ever reported hearing the slightest issue, merely heighten both the bewilderment and amusement. Thanks. Have nice day.

 

[antcollinet]

More sea lioning going on here.

Please god….make it stop……

Exactly the reaction the average sea lion aims to provoke.

 

[RandomEar]

It has thanks you have proven my exact point. No one has actually ever heard an issue.

Full on clipping at normal listening levels with high end headphones = "No issue". Sure, that's totally what I said.

Misrepresenting what was said, ignoring all explanations, ignoring the inconvenient parts of the data and the argument by supposed authority on top. Onto the ignore list it goes!

 

[Henry53]

Full on clipping at normal listening levels with high end headphones = "No issue". Sure, that's totally what I said.

Misrepresenting what was said, ignoring all explanations, ignoring the inconvenient parts of the data and the argument by supposed authority on top. Onto the ignore list it goes!

Again that no actual test has ever reported!