Astell & Kern A&ultima SP1000M

Mmm…  Da ba dee, da ba daa.

PROS: relative to SP1000 – smaller size/weight, very similar tonality, the same processor, DAC, and other critical components, $1.1k cheaper.

CONS: removed optical out, 128GB internal storage (down from 256GB).

The product was provided to me on loan by Astell & Kern for the review purpose in exchange for my honest opinion.

Manufacturer website:  Astell&Kern.  Available for sale directly from A&K, Amazon or other retailers, like Audio46.

My original full SP1000 SS/CU review was posted here.


Just when you thought Astell & Kern were done for this year with new DAP models and everything is finalized with flagship A&ultima (SP1000 SS/CU), mid-fi A&futura (SE100), and entry A&norma (SR15), A&K throws us a curveball with a brand new SP1000M which came out of the blue, no pun intended since the color of this DAP is actually lapis blue.  And to an even bigger surprise, they took key components of SPK, including dual flagship AKM DAC and Exynos octa-core processor, and packed it into a smaller and lighter aluminum chassis while dropping the price by 30%.

But first, before I go into more details including the comparison to the original SPK, let me calm down all the current A&ultima flagship owners – there is NO NEED to panic!  Your SP1000 SS/CU is not obsolete and still very much relevant, especially after the recent FW 1.10 update where Open APP Service was added just like in SPKM.  But, if you have been narrowing down the available flagship DAP choices and had your eyes on SPK, the option of SPKM shouldn’t be ignored.

Due to similarities in GUI, comparison to other DAPs, and pair-ups with headphones which I have already covered in my SPK SS/CU review, I’m not going to repeat it again here.  You are welcome to read that review separately because the focus of this shorter write up will be strictly on the comparison between SPKM (SP1000M) and SPK (SP1000SS).

Unboxing comparison.

With a noticeable price difference, you have to cut corners somewhere, and it begins with unboxing where instead of a solid wood storage box of SPK, the SPKM arrived in a sturdy cardboard box inside of a blue sleeve, just like a color theme of the new DAP.  Also, I didn’t find A-pin which SPK included for microSD card tray.  Made sense after the further examination of SPKM since it has a spring loaded microSD (not a tray which requires a pin).  Other than that, you still find 2 sets of screen protectors, nice quality thicker USB-C cable for fast charging and data transfer, and a premium black soft real leather case.


If you want an alternative case with a slimmer color matching option, MITER also released their SPKM case, available on Amazon now.  As usual, even for just an accessory, MITER packs it in a nice gift box and a protective sleeve.

MITER case is slimmer than A&K stock case, and I like the idea of a blue matching color.  The leather is soft to the touch, has a generous USB-C port opening at the bottom, and fully exposed top for easy access to the ports and the volume wheel.  Buttons (Plays/Pause/Skip) are covered and have a nice indent to outline their shape.  Also, this case comes with MITER signature magnetic kick-stand which is very slim and doesn’t add too much of extra thickness on the back.

Design comparison.

Right out of the box you quickly realize how much smaller and lighter SPKM is relative to SPK.  With dimensions of 67.9mm x 117mm x 16.9mm and weight of 203g, SPKM is more compact relative to SPK with 75.8mm x 132mm x 16.2mm and weight of 388g (SS) or 418g (CU).  Smaller size also means smaller LCD display, going down to 4.1″ from 5″, though touchscreen resolution remains the same, 720×1280.  Now, I can easily use it in one hand where my thumb can reach across the entire screen, like going from the newer iPhone to iPhone SE.  Also, smaller size, smaller display, and use of aluminum chassis results in a reduced weight by almost a half.

Other than a scaled down dimensions, overall exterior design is very similar with only a few noticeable changes.  The bottom of the DAP still has USB-C port in the middle, but the 5-pin connector to the left of USB-C in SPK (for external amp mating) is no longer there in SPKM.  Instead, SPKM has a spring loaded microSD card port to the right of the USB-C.  With M intended for a mobile/portable use, the assumption here is that users won’t be looking for an external amp stack up to make the DAP bulkier.

On the right side you will still find a volume wheel, resembling a watch crown, with a nice tactile click response as you turn it.  But in SPKM it’s just a volume wheel, no longer a power push button.  That’s when I quickly realized how much I got spoiled by SPK where you can turn the screen on/off by pushing the volume wheel, while in SPKM you have a separate power button at the top and the volume wheel is just for volume adjustment.

At the top, you still have your 3.5mm TRS single ended and 2.5mm TRRS balanced headphone ports, except SPKM no longer has a shared optical digital output with 3.5mm headphone port.  This means you no longer have optical digital out to drive external DAC/amp, but you can still use USB-C digital out (USB OTG), turning SPKM into a transport which I have verified with Micro iDSD BL dac/amp.  And as mentioned already, while SPK has a microSD card tray in the right corner on the top, SPKM moved microSD to the bottom and has a separate power button used for power on/off and screen on/off.

The left side has transport control buttons with Play/Pause in the middle and Skip buttons on each side.  Here the buttons are different from SPK, looking exactly like in SE100.  Those are unlabeled narrow rectangular buttons, spaced close to each other, and raised higher for an easier “blind” id.  Unlike SPK where you have 3 round buttons with Play/Pause in the middle with id bump, these SPKM buttons are spaced a bit too close.  I’m sure majority will be using SPKM in its provided stock leather case, and the case itself has these buttons covered and imprinted with corresponding labels.  Still, even the imprint is not that well defined, but I don’t consider it a show stopper because I’m sure either Dignis or MITER will probably have their custom cases in a near future.

Under-the-hood comparison.

The “under-the-hood” spec was of a high interest to me because it’s a physically smaller device, making me wonder what’s in and what’s out.  To my surprise, SPKM still has a dual (2x) AKM AK4497EQ DAC, Exynos 74200 Octa-Core CPU, support of BT v4.1 with aptX HD codec, USB type-C with fast charging, and a single microSD card.  The core of the design was still there, but there are some other differences.

The one I mentioned already is a reduction in display size, going from 5″ to 4.1″ – still large enough and easy to read with the same 720×1280 touchscreen resolution, though SPK display is a little brighter.  Chassis are aluminum now, in comparison to stainless steel or copper chassis of SPK, making SPKM lighter.  Internal storage is reduced from 256GB to 128GB – not the end of the world considering the available streaming options and microSD card capacity going up.  Keep in mind, once you install Tidal (not the custom one which comes preinstalled with A&K DAPs) and Spotify apps, you have an option for off-line storage to either internal or external memory.

Battery size was also reduced, from 3,700mAh to 3,300mAh – resulting in battery life to go down from 12hrs to 10hrs, which I have verified with SE output, 75/150, playing a mix of mp3/flac files.  Another change, according to the spec, is SPK SE (3.5mm) 2.2Vrms and BAL (2.5mm) 3.9Vrms while SPKM SE 2.1Vrms and BAL 4.2Vrms – the higher voltage/power of BAL output is noticeable in comparison where I needed to reduce a volume by about 3 clicks.  Also, from SPKM spec, it gained 1dB of SNR, going from 122dB to 123dB – the background is still black, and this particular improvement would be hard to hear anyway.

Other changes I’ve already mentioned about were No optical output and No external amp docking with SPKM, which makes sense since M-model is designed for a portable use.  If you want to use your A&K flagship DAP with their own external amp dock (if one ever going to be designed for A&ultima), then you need to look into SPK.


Page 2: GUI and Open APP Service, Sound comparison, and Conclusion.


49 thoughts on “Astell & Kern A&ultima SP1000M

      1. Certainly, but I don’t have access to se100. Also heard from other trusted sources, it’s technical performance is nowhere near SPK. But that’s other peoples opinion 🙂


    1. I’m considering one of these or a cowon l. Which would you recommend? Also, is there a big difference soundwise between the blue and gold?


      1. In term of the sound, they are on par, but a big deciding factor here are the features. PL is audio playback only, has 4.4mm balanced, and LOTS of sound tweaking thanks to JetEffect dsp effects. SPKM has no sound tweaking (Eq is useless), has 2.5mm balanced, and access to streaming up. Pick and choose your priorities. Also, there is a price difference. The last time I checked (from amz link in my Plenue L review), the price was down to $1799. So keep in mind, if you want streaming and don’t care about sound tweaking, go with SPKM, if you don’t care about streaming and want sound tweaking (and lighter weight) – PL.


  1. Personally, I preferred SPM compared to SPK due to the subtle warmness and the extra body on the note. Was always a fan of WM1Z but I find the resolution/clarity is lacking (Without any mod, never tested one with them). SPM will just fit right in my pocket and I think others who has the same dilemma might consider this option 🙂


  2. Hi, I own the SE100 and love it, but I am planning to exchange it for the SPKM in a few days. I am a little surprised to read the SS is not as holographic on the spkm vs spk, all the other reviews I’ve read say the spkm sounds superior. I use it with the Shure SE846, balanced out with Litz silver cable.


    1. Hmm, I did write in my review that SPK (SP1000 SS) has a more holographic soundstage in comparison to SPKM (SP1000M), so you could have misread it? I’m not aware of any official SPKM (SP1000M) reviews, only a few impressions from the show in a noisy environment and from reporters. Keep in mind, we hear things differently and use different headphones, not everybody hears the same. But I did spend a dedicated time with SPKM to give it a good listening over many hours with different headphones. Plus, just think about it, why would A&K make a much cheaper product to sound “superior” and to kill it’s flagship? 😉


      1. hahaha, I knew you gonna quote this article, yeah, we talked about it in SP1000 thread on HF for awhile. Besides my official review/comparison, there are only 2 other references peope bring up. Whathifi posted their impressions specific to SPKM and under a sound description only mentioned how a few songs sound played on SPKM. No comparison or detailed sound analysis, just an impression, right?


    2. I might be late to the discussion but here my unbiased thought on it and shall serve as personal reference only.

      You cannot go wrong with both. Its a matter of preference and music genre. Tested them and they have their own pros and cons. This was done under blind test with the help of 3rd parties. I find that the “holographic” which i presume is “soundstage” is part of the circles as well.

      SPKM = (More personal and intimate with hint of warm) and SPK = (Wider amidst very little and more reference sounding – remind me of hugo 2). Thus if you are a classical person, SPK will be your choice and if you are like me who like warm and intimate feeling (WM1Z fan base), get SPKM.


      1. Thanks for that. Just want to point out that the spkm on balanced out has slightly higher SNR, lower clock jitter and lower THD . Just saying.


  3. Hi Alex.
    I know you don’t own the spk cu, but would you say the sound of the sp1000m leans towards the cu version more so than the ss version?.Is it right to say that sp1000m is just as warm as Cu ?. Would you recommend a warmer monitor to pair with sp1000m, say the EE phantom?


    1. I can’t make the assumption about CU version. Throughout fw updates, SS version got warmer due to smoother treble rendering. I don’t know if CU got warmer or more revealing, or just more resolving… SPKM pairs up great with any signature monitors. It just makes the sound more natural, more organic without taking away from resolution. Not familiar with Phantom, but heard it is on a warmer side. Probably should pair up well with SPKM. I also heard Phantom hisses with man sources, while A&K is known to be hiss free.


  4. Thanks for the review. I read some other ones concerning sp 1000. Thanks for your insight. I was wondering if you could advise in something. I have ordered 64 audio U18 and currently have A&K 300. But I want to upgrade to spk copper or perhaps spkm. I do love a bit warmer ( full bodied sound) but also love the wife stage where you can hear all the instruments what combo would you suggest to complement the u 18 ?

    Thanks a lot


    1. I only heard SPK CU for a short time with early fw releases, and found it to sound warmer in comparison to SPK SS. If you are not trying to save money (SPKM is cheaper, of course), SPK CU will probably be better for sound sig you are after.


      1. Hello , I have last question Some reviews stated that the 64 audio (U18) universal IEM sound noticeably worse that the custom fit. Because of fit ( seal) issues the sound signature was not as good as in the custom fit models. Did you have the same observation with any of the models ? I am thinking of getting custom tips from Custom Arts for the U18 as it is too late to change my order. Would you say that that might be better ? Thanks a lot for your time 🙂


      2. the only difference I observed in the past between 64audio U12 and A12 was the bass impact, with CIEM having a lot more vs universal version having “variable” amount which I can control by switching between different eartips (better seal – more bass).


    1. U18t is my favorite iem. But I do use the largest eartips, went through a number of different ones until I found the right fit for MY ears. The right fit is a key to a perfect sound.


      1. Hello
        Would you mind sharing what tips you found to work best for you ? I have quite small ears so I will have to investigate. Thanks


      2. I reviewed dozens of IEMs, saving eartips from all of them, and also got dozens of eartips from ebay and from, so I go trough everything to find the biggest (large or extra large) pair of eartips to give me a seal. It’s easier with small ears to get a seal. While a struggle with large earcanal opening 😉


  5. Hello,
    I know you had a chance to listen to both u18t and U12. The base in the U 12 is what I really liked the most and there was also more body to the vocals comparing to the U18. I listened to it on my AK300. Would you say that the bass and mids on the U 18 improve on the spk copper ? I am still debating if I did the right thing chosing the U 18. I loved the sound stage and the clarity in really busy recording ( lots of instruments). In those situations I couldn’t listen to those tracs on U12 as they seemed too chaotic. But on U 18 they were enjoyable. But I also loved the base on the U 12. So I wonder with the much better source they would sound Fuller ?
    Thanks a lot for your time. 🙂


  6. Hello. ,
    Thanks a lot. I totally agree with your reviews. Except I felt the U 18t had less bass than U 12t but it may have been due to the seal problems. I had both home for several days it it was so hard for me to decide. Each was good at something. But if seal was a problem than the U18 shouel be the ones. If it will have a similar amount of bass that they should be perfect.


  7. Hello!
    I found your review very informative, however I have one question about your comparison of SPK and SPKM after fw update. I will quote: “I also noticed no changes in the sound of SPK after the update.” This description is double-edged for me, I don’t understand, is SPKM has no changes in comparison to SPK after SPKM’S fw update or is SPKM has no changes in sound before and after the update?

    Thank you!


    1. Sorry for the confusion, it was more of a side-comment specific to SPK only and its own FW update which enabled side-loading of apps (thus aligning it with SPK M in terms of streaming capability). I meant it that I didn’t notice any sound changes in SPK after updating its own fw…


  8. hi twister, I always enjoy reading your review.. Currently I have hiby R6 with me.. Do you think its worth to upgrade to SPM? Is the SQ improvement is noticeable from R6 to SPM? I used Trio and MH334 as my daily iem as a reference. Thanks.


    1. we are talking about price difference of about $1900, right? Don’t think you will get that much of an improvement. With SPKM you don’t have to worry about high impedance output and it has a smoother tonality, but if you want to stream apps you will have to side-load apk with A&K daps, while in R6 you just download/install from Google Play. Also, R6 will give you lots of tools for sound adjustment (HibyMusic has EQ and DSP effects), while A&K DAPs EQ has a very subtle adjustment… I mean, personally I would choose A&K DAPs over R6/R6Pro, but it all depends on your budget and expectations. Going up in price from R6 to SPKM is all diminishing returns.


    1. I’m only familiar with Trio. Either one will pair up well, SPKM will be smoother and more musical while LPGT will be more revealing and more analytical. Up to you to choose.


  9. Hi twister
    I’ve bought a SPKMGold few weeks ago and I liked some aspect of it. I used to play with cans instead of IEMs, now the SPKM really hooked me into the IEM territory. I have a few questions I hope you’d be able to share some opinions. Is the SPKM/G vastly inferior to the SPKCU/SS? I’m currently running Campfire andromeda, Solaris, and noble K10. I’m looking forward to add an 64 audio u/a 18t to my collection. But if the SPKM/G is inferior sounding stuff I may consider buying another totl DAP instead of the U/A18t. (I do get congestions with some tidal master tracks recently with all three of my IEM, electronic music mainly(maybe the track was badly composed for iem). My ZMF auteur/eikon and hd800s never had those congestions with WA8 amp, that’s why I’m wondering the spkmg is less than totl..)


    1. SPKMG shouldn’t give you “congestion” of sound in comparison to its bigger brothers. There is a slight variation in tonality (coloring) and some subtle soundstage difference (more noticeable when comparing 2.5mm balanced outputs). But congestion here might be the result of you used to open back full size headphones vs in-ear monitors? I know some people find the sound to be less expanded, less layered going from open back cans to sealed IEMs. But also, warmer fuller body tonality of SPKMG will yield a different pair up results when compared to a more neutral and more revealing reference sig of something like LPGT.


      1. Thanks for the reply! I think I’m a bit tired of the warmer sound after everything I have is quite warm. I’ve heard a lot of good things about LPGT so I’ll probably try it out at some point. I saw your review of SP1000 included a lot of IEMs I’m interested in, such as Empire ears legend X, 64 Fourte, and 64 u18t. But I’m wondering how will these three fair with the SPKMG compare to the SP1000? Thanks!


      2. I only have SPK SS, so can’t tell you for sure about those pair ups, but it should be fairly close, maybe a little thicker in mids/vocals. Keep in mind LX is a BASShead tuned iem, Fourte is a TREBLEhead tuned iem, U18t is still my favorite iem at this current moment.


      3. Thanks again! No LX for me I suppose. But I don’t mind “treble head” IEM as much as a bass heavy ones. I’m leaning towards U18T even more now. Thanks for all the reviews they have been very helpful! Wish you all the best.


  10. Hi twister, When I did read your review, I bought a SPK SS BLACK ONYX, which comes from home (AK) incorporates firmware fw 1.07, well now, I am not very interested in Open APP Service since I only intend to hear my own files in AIFF, FLAC .., but my intention is only to use it with my own files, so by reading your review about the firmware updates and possible sound change, you did write that version fw 1.07 SPK SS improved the version 1.06 and practically equal to the warmer sound SPK CU fw 1.06, so if It’s no my intention to use Open APP Service u others Apps, would you recommend to continue using version 1.07 in my SPK SS Onyx? or should update if you consider that there are improvements, but always changes in reference to the sound only. thanks in advance and regards my friend.


    1. not just changes or improvements (relative to what you consider an improvement or side-grade), but they also implemented some fixes. A few bugs were reported by users on Head-fi and A&K followed up with fixes.


  11. Thank so much, therefore I understand that it is advisable that I update the SPK SS firmware from 1.07 to the latest version 1.17 regardless of whether to use Open APP Service just for the fixes, bugs or improvements in the system. Anyway also, I read in your review once you update to fw 1.07 you can’t roll back to the previous version, so please be aware of the changes, so if I update the firmware I can’t roll back to the previous version u others although I make a Factory Reset: Delete all user data and restore the device to its original factory settings.??
    Last SPK SS fw is 1.17?
    Thanks again and sorry to bother you…


  12. Hi Twister,

    Nice review! I have a few questions if you don’t mind taking some time to answer. I’m planning to get either SP1000 SS or SP1000M Blue, I’m currently using Noble Encore as my main monitors. What would you recommend? Just for a background, I own and do love my Senn HD800 sound paired with Questyle CMA600i. I like the expansive soundstage, clarity, resolution and dynamics.

    Cheers and Thank you!


    1. Either one will pair up great with Encore. While SS will have a slightly wider soundstage expansion, the change could be subtle to your ears. If money no object, SP1000SS is the top dog. But if you want to save a chunk and want something more compact – M is great. Also, keep in mind, A&K is due for a new flagship, which could be announced toward the end of the year, driving prices down and/or making 2nd hand units available at a cheaper price. But nobody knows when those will be announced.


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