Astell & Kern Kann Ultra DAP Review

[leonasj500]

I don't think I will be able to tell the difference in a blind test if I plug the same pair of headphones into the Kann Ultra vs Qudelix T71 and set them to the same volume, except I can maybe hear the noise issue of the Kann Ultra at High and Super gain as pointed out by Amir. Since Kann Ultra is my only DAP and I went back to using phone/laptop + Qudelix T71 afterwards, I don't know how it compares with other DAPs.

but one of Amir tabs shows kann ultra has audible noise even from 30-50ohm headphones even at 2Vrms gain

 

[HELIAS]

but one of Amir tabs shows kann ultra has audible noise even from 30-50ohm headphones even at 2Vrms gain

That graph means it can't make low impedance low sensitivity headphones (planars typically) loud. The steep hill on the right is not noise but distortion due to clipping as the electric signal exceeds the circuit's current limit.

 

[leonasj500]

That graph means it can't make low impedance low sensitivity headphones (planars typically) loud. The steep hill on the right is not noise but distortion due to clipping as the electric signal exceeds the circuit's current limit.

i dont understand grapgh. but if use 50ohm headphone or iems you can listen only at low volume only? i have shanling m7 and even at max volume 50ohm sounds not changes,but too loud me,where my sold ak sr25ii at loud volumes starts hiss and too brightens sound. correct? but sr25ii was 4Vrms ,where m7 shows 6Vrms power.

 

[HELIAS]

i dont understand grapgh. but if use 50ohm headphone or iems you can listen only at low volume only? i have shanling m7 and even at max volume 50ohm sounds not changes,but too loud me,where my sold ak sr25ii at loud volumes starts hiss and too brightens sound. correct? but sr25ii was 4Vrms ,where m7 shows 6Vrms power.

I can't comment on any device you mentioned. I don't own them.

Kann Ultra's output at 50 ohm is not impressive but still should be enough for most headphones except for some very low sensitivity planars, and more than enough for all IEMs.

 

[leonasj500]

I can't comment on any device you mentioned. I don't own them.

Kann Ultra's output at 50 ohm is not impressive but still should be enough for most headphones except for some very low sensitivity planars, and more than enough for all IEMs.

so,sp3000 way better sound quality at 50ohm?

 

[HELIAS]

so,sp3000 way better sound quality at 50ohm?

No. Amir's chart is in dB. At 1V 50 ohm, the Kann is -100dB which is 0.001%. https://sengpielaudio.com/calculator-thd.htm

Neither product is worth its price anyway. Nor is any other DAP in this price range.

 

[leonasj500]

No. Amir's chart is in dB. At 1V 50 ohm, the Kann is -100dB which is 0.001%. https://sengpielaudio.com/calculator-thd.htm

Neither product is worth its price anyway. Nor is any other DAP in this price range.

so,if i use only one iem- sony ier-z1r and want ak sound house,best idea get SE300,Sp3000m vs kann ultra? as i dont use headphones with dap and sony z1r iem is 40ohm impedance. so,with kann ultra sony iem im listen at volume 15/150 ,where with se300 or sp3000m listen volume will be normal 50-65/150 ? correct? i had sr25ii and ier-z1r was about 70/150 volume normal listing volume,but if try 80 -90 starts hissing.

 

[HELIAS]

so,if i use only one iem- sony ier-z1r and want ak sound house,best idea get SE300,Sp3000m vs kann ultra? as i dont use headphones with dap and sony z1r iem is 40ohm impedance. so,with kann ultra sony iem im listen at volume 15/150 ,where with se300 or sp3000m listen volume will be normal 50-65/150 ? correct? i had sr25ii and ier-z1r was about 70/150 volume normal listing volume,but if try 80 -90 starts hissing.

I don't have a recommendation, nor am I interested in discussing "house sounds" of DAC/amps whose only job is to be noise free and distortion free. It would also be hijacking this review thread to discuss DAP recommendations here. Please make a separate post about it.

 

[leonasj500]

You seem to be placing too much emphasis on the idea that "they should sound different." Two high-quality, properly functioning daps or dacs&amps should not sound different under the same conditions to human ear. If there is clear audible difference, it might suggest that one or both units are defective or not performing as intended. If they sound different and both claim to be "hi-fi" , then which one is the true "hi-fi"? Or one is more "hi-fi" than the other? doesn't make any sense to me.

received sp3000m.this AK f****ing sounds so good. i like it a whole new world-musical,micro,macro details.resolution,soundstage.imaging,clarity. now i see differnce 3K dap vs 1K dap sound,but battery fast dry. maybe needs some time charge to get optimal work. its great upgrade to m7. faster ui, faster wifi, 8gb ram, 256gb rom,more power 5.4Vrms vs 6.3Vrms.. f**k impressive Crossfeedthat soundstage sooo big ,that full bass so sweet,bass not overshadows mids,- ,vocal a bit front moved ,and so extended total full treble-with ier-z1r -dream combo. i dont know better set for me.

 

[karloss23]

I was surprised to read these comments and review.. I own a Kann Ultra and it is paired with low impedance HiFiMan Arya Organic headphones (16 ohm) I've never experienced any audible distortion. After reading this I decided to back to back the Kann with my Apogee desktop interface, and my iphone with Qudelix dongle and the Kann just sounds a lot better overall. Clearer and more defined at the highest volume I find comfortable. I use the mid gain setting and have 4.4mm balanced cable.. Are the charts maybe showing distortion that's not audible or only audible at levels that are unlistenable? Sorry I don't know how to read the charts properly to undertand the volume level where this should be a problem. To me the Arya Organic + Kann Ultra is the best headphones experience I've had and I've been well into audio (amateur music production) for over a decade.

 

[antcollinet]

I was surprised to read these comments and review.. I own a Kann Ultra and it is paired with low impedance HiFiMan Arya Organic headphones (16 ohm) I've never experienced any audible distortion.

This is not a big surprise. This device performs well below state of the art - which is why it has been given a rough ride considering it's price.

On the other hand, it still has levels of distortion low enough to be inaudible for the vast majority of people in real world listening.


Regarding your comparisons with the Qudelix - if you don't compare blind and properly controlled (especially accurate level matching) then your listening comparisons don't tell us anything. Human hearing perception is always influenced by what we know about what we are listening to.

Finally

Welcome to the forum

 

[oleg87]

I was surprised to read these comments and review.. I own a Kann Ultra and it is paired with low impedance HiFiMan Arya Organic headphones (16 ohm) I've never experienced any audible distortion. After reading this I decided to back to back the Kann with my Apogee desktop interface, and my iphone with Qudelix dongle and the Kann just sounds a lot better overall. Clearer and more defined at the highest volume I find comfortable. I use the mid gain setting and have 4.4mm balanced cable.. Are the charts maybe showing distortion that's not audible or only audible at levels that are unlistenable? Sorry I don't know how to read the charts properly to undertand the volume level where this should be a problem. To me the Arya Organic + Kann Ultra is the best headphones experience I've had and I've been well into audio (amateur music production) for over a decade.

According to Amir's measurements, your headphone will clip around ~108dB peak SPL. That's a volume I find intolerably loud. Not sure what's going on with the noise, but audible noise should be fairly obvious.

 

[karloss23]

According to Amir's measurements, your headphone will clip around ~108dB peak SPL. That's a volume I find intolerably loud. Not sure what's going on with the noise, but audible noise should be fairly obvious.

Thanks a lot for your help translating those numbers .. yes I would never listen at 108DB, that seems like dangerous levels for headphones so I don't think the issue will manifest for me anyway .. One more question if you can help, the Kann Ultra has software VU meters, if I were approaching levels where this clipping was an issue would the VU meters reflect that by pushing into the red?

 

[AndyBell]

Leaving aside the actual device, Ive had the DAP vs smartphone discussion so many times on here. The usual points for a DAP seem to be "getting away from phone" , " dont need a dongle (a fair point)" and large storage (fair point but 128/256gb on phone storage is v common today) .

I'd be streaming anyway for the most part on either device and for me I'd get a sub £300 android device and a decent 2v dongle that has the power needed for most IEM/ Dynamic driver 'phones for sub £50 that would be slimmer , better UI etc and I would tether it to my main phone hotspot which is unlimited with maybe a few gb of downloaded for dead zones. Ive spent less than 1/3 price, possibly better performance (why anyone would be mobile in heavy hard to drive 'phones is beyond me ) and I have got a backup phone should my main phone again fall in the pot whilst in my back pocket.

My portable setup is a Samsung Galaxy A16 with 2tb SD card. WiFi is connected for Qobuz streaming but I don’t have a phone sim in it.

I use a FiiO BTR17 DAC - sometimes wired and often Bluetooth (LDAC) when I don’t want the fuss of wires.

I have Neutron music player with EQ settings for my headphones (Sennheiser HD560S or Etymotic ER2XR) and it sounds very good. If there is a difference between wired and LDAC Bluetooth I can’t hear it.

If I’m using the Qobuz app I use the BTR17’s PEQ. Otherwise I set it to off.

I like the flexibility of the setup and when the A16 eventually fails, it’s a lot less £££ than most DAPs to replace.

 

[M.C. Logan]

My portable setup is a Samsung Galaxy A16 with 2tb SD card. WiFi is connected for Qobuz streaming but I don’t have a phone sim in it.

I use a FiiO BTR17 DAC - sometimes wired and often Bluetooth (LDAC) when I don’t want the fuss of wires.

I have Neutron music player with EQ settings for my headphones (Sennheiser HD560S or Etymotic ER2XR) and it sounds very good. If there is a difference between wired and LDAC Bluetooth I can’t hear it.

If I’m using the Qobuz app I use the BTR17’s PEQ. Otherwise I set it to off.

I like the flexibility of the setup and when the A16 eventually fails, it’s a lot less £££ than most DAPs to replace.

£150 buys a perfectly capable dap, avoiding all the mess and fuss you appear to have created for yourself. Where I live if you go more than a few hundred metres from houses on the road you only get voice on the mobile network, so streaming is moot. Like most people, if using headphones in the house they are plugged into my hifi, so WiFi streaming to a portable is pointless. Multiple 200GB Micro SD cards carry the bulk of my library, which, of course, can't be used in my choice of mobile phone (Google Pixel, for the cameras) as the best mobiles no longer have card slots. Why do people have to insist that other people's use cases aren't valid?

 

[antcollinet]

Why do people have to insist that other people's use cases aren't valid?

Where in the post you quoted was that stated? Or even in the post that one quoted? As far as I can see, both posts stated their reasons for using a phone. Neither suggested your use case wasn't valid for you - just not for them.

 

[AndyBell]

£150 buys a perfectly capable dap, avoiding all the mess and fuss you appear to have created for yourself. Where I live if you go more than a few hundred metres from houses on the road you only get voice on the mobile network, so streaming is moot. Like most people, if using headphones in the house they are plugged into my hifi, so WiFi streaming to a portable is pointless. Multiple 200GB Micro SD cards carry the bulk of my library, which, of course, can't be used in my choice of mobile phone (Google Pixel, for the cameras) as the best mobiles no longer have card slots. Why do people have to insist that other people's use cases aren't valid?

Is there a £150 DAP that supports everything that Neutron player does, such as headphone EQ, separate PEQ, Crossfeed, etc plus SE and Balanced output, can drive high impedance headphones, can link to my PC, can run Qobuz/Spotify/Amazon music? I can also check email and read the news on the A16 whilst listening to music. Its quite convenient.

I don't live where you live - I get 4g all over town on my iPhone, although my A16 doesn't have a sim so I don't stream outside using it.

Evidently I'm not like 'most people'. I often use the headphones in the kitchen when cooking/washing up...

I'd say the flexibility of the BTR17 connected to the phone using Bluetooth, leaving the phone freely accessible without a tangle of wires is worth the 'fuss'.

"Why do people have to insist that other people's use cases aren't valid?"

Theres an irony to that statement...

 

[jarmo]

Richer Sounds are currently offering this device at £999 (£600 off).

Still seems way overpriced for something that streams/plays music and can fit in a rather large pocket.

Wonder what sales numbers are like on these? Might not need to make so many if the market is small. OTOH, might not matter so much if
A&K make too many if the markup is so high they break even on the thousands made with the first few hundred sales...

Funny old game is audio… even more opinions than ears.

 

[Somafunk]

Richer Sounds are currently offering this device at £999 (£600 off).

They'd have to drop another £899 from the price before I'd consider, my £50 tempotec v1 would be just as equally transparent in use, and at the size of stick of chewing gum rather easier to carry.

 

[Henry53]

This is a review and detailed measurements of the Astell&Kern Kann Ultra DAP. It is on kind loan from a member and is on sale for US $1,499.
View attachment 444562
Forget any notion you have of a smartphone. This thing looks like one but is far, far heavier and thicker. Machining has left sharp corners which are unkind on fingers. The rotary volume control is slow and the display for it does not keep up.

On positive front it has wifi streaming including support for Roon! Didn't see that coming from a portable player. I tested both Roon streaming and playback using its USB-C cable. Yes I know, many will use an SD card with it but performance should be the same.

There are a set of balanced and unbalanced connections for Line and Headphone out:
View attachment 444563
As you see, labels are hard to read. The heavy weight of the unit comes in handy when using it on the desktop.

Astell&Kern Kann Ultra Measurements
Let's start with line out at max volume using balanced output:
View attachment 444564
This is impressively good for a DAP! Distortion is inaudible and noise floor is good. Both suffer though with unbalanced output:
View attachment 444565

Measuring noise by itself, it turns in very nice numbers, almost approaching dedicated desktop products:
View attachment 444566

There are selectable filters; I chose the fast linear which resulted in nice frequency response:
View attachment 444567
Linearity is as it should be:
View attachment 444568

Story becomes less good when we look at IMD distortion:
View attachment 444569
Jitter seems unsightly, though inaudible:
View attachment 444570

Multitone shows raised noise floor at lower frequencies:
View attachment 444571

That is a clue to issues there when we run distortion vs frequency:
View attachment 444572

To save my sanity, I only tested balanced headphone out, starting with 300 ohm load:
View attachment 444573
While we have plenty of power in max "Super" setting, there is much elevated noise. Even more strange is very limited power at 32 ohm:
View attachment 444574

We can see the strangeness in full exposition when we sweep impedances using high gain:
View attachment 444575

This is not how it should be for a device that is very focused on headphone output.

Conclusions
The Kann Ultra starts strong, turning in very good noise and distortion numbers as a DAC using balanced output. From there though, cracks in the foundation is seen, culminating in a headphone stage that is very poorly designed when it comes to gain management and low impedance loads. It should however be good if you use high impedance headphones.

Overall, this seems like partial improvement. And partial improvement is not what want to see in a device that costs $1,500.

I can't recommend the Astell & Kern Kann Ultra DAP.

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