Astell & Kern A&ultima SP1000 SS/CU

Sound Analysis.

The first thing you notice when start listening to SP SS is the width of the soundstage. When I first tested it with fw 1.06, I found it to be the widest soundstage expansion I heard from any DAP to date. With fw 1.07 it shrunk a bit, and then expanded back in fw 1.08, though never reaching the level of the original ultra-wide expansion. But nevertheless, in fw 1.08 soundstage width is still very impressive. SP has a good natural staging depth too, more out of your head than intimate, but the sound is not exactly ultra 3D holographic (though, came close in some pairs up), rather more oval shaped, spreading from far left to far right, yet with boundaries to keep it realistic rather than exaggerated. I’m not saying that it will make your IEMs or closed-back headphones sound like open-back, beyond their tuning. But based on my experience of testing many different DAPs, SP pushes the performance of iems/headphones to their absolute limit.

SP SS tonality is closer to neutral-brighter side with a precision of micro-detail retrieval. It’s especially noticeable in mids and lower treble where you have excellent layering and separation of the sounds. For someone who wants to spend hours analyzing every single detail of your hi-res recording, you can really get lost nitpicking every sound while listening to this DAP. With the original fw 1.06, the tonality was colder, more analytical, but the follow up 1.07 and 1.08 updates added a little more natural body to the sound and took an edge off the treble. As mentioned already, A&K official statement is that firmware doesn’t change the tonality, and I’m not going to argue about it, just want to describe what I’m hearing because to my ears with 1.08 update SP1000 SS had a tuning which reached a happy balanced medium between what I heard with CU (fw 1.06 with a warmer thicker fuller body sound, and still a great resolution and layering) and SS (fw 1.06 with a colder analytical sound and an ultra-wide soundstage expansion).

It’s always a matter of personal preference and will also depend on a pair up synergy with different IEMs/headphones and their corresponding sound sig. As I always point out in my DAP reviews, when you are describing DAP sound, you are talking about a pair up synergy with iems/headphones you’re listening to. Thus, I always choose a more balanced and less colored IEMs to analyze the sound of DAPs. So, when I tested and compared SS vs CU, I found them to have more similarities in upper mids/treble tonality, while the bass and the lower mids is where I hear the bigger difference. SS has a more neutral bass with a little less sub-bass rumble and slightly less mid-bass impact, and a little leaner lower mids, giving the sound a more neutral tonality with more analytical precision. CU has a little fuller sound with deeper sub-bass rumble and more body in lower mids, giving the sound a warmer, smoother, and a more natural tonality. Upper mids and treble are close between SS and CU, but I do hear a little more crunch with SS, especially noticeable with some electric guitar tracks. The sound resolution is very similar, and both have a great vertical dynamic sound expansion with an excellent retrieval of details.

Also, in both SS and CU variants, I found a common difference between balanced 2.5mm and singled end 3.5mm ports where soundstage shrinks a little bit and the background is not as black anymore from a single ended port.


All comparison was done using SP1000 SS with the latest fw 1.08. I used 64 Audio U18t, UM Mason V3, and Senns IE800S for sound evaluation, matching the volume between the sources.

SP1000 SS (fw 1.08) vs Sony WM1Z (fw 2.0) – I’m sure many will be interested in a comparison to WM1Z since at the current moment these two are the top choices for many audiophiles looking for a summit-fi portable source. Soundstage expansion was very close in fw 1.07, though after 1.08, SP is a little wider. Tonality does vary, where I hear WM1Z to sound warmer. Both have excellent technical characteristics with a very good dynamic expansion of the sound. In a more detailed sound analysis, WM1Z has more emphasis on sub-bass rumble and mid-bass punch while SP bass is more neutral, tighter, and with shorter decay in comparison. Both have very resolving layered mids, where SP has more transparency and more micro-details while WM1Z is a little warmer, smoother, and more musical. Also, both have a great treble extension, though I still think WM1Z has more sparkle while SP (especially after 1.08) has a touch smoother treble. With some of my earphones where I have a more pronounced 12k peak, in comparison to 1Z, SP pair up took an edge off the treble.

SP1000 CU (fw 1.06) vs Sony WM1Z (fw 2.0) – I only had CU w/1.06 for a short period of time and based on my testing heard a very similar soundstage expansion between these two. Also, WM1Z still had a little more warmth in tonality, deeper and beefier sub-bass with more rumble, and a stronger mids bass impact. CU bass is a little tighter, has a little less sub-bass quantity, and a little shorter decay in mid-bass. Furthermore, CU has a little smoother treble, while WM1Z has a little more sparkle in treble. Both have a warmer tonality, but WM1Z just a little warmer. Also, WM1Z lower mids are a touch leaner in comparison to CU.

Both SP1000 SS/CU and WM1Z are on a bigger and heavier side, and depending on a chassis material, the weight is: SP1000 SS 388g, SP1000 CU 418g, and WM1Z 452g. While WM1Z is the heaviest, it’s a little narrower, giving it a slightly better grip if you have smaller hands, though SP is slimmer/thinner. But either way, these are not lightweight pocket friendly DAPs, though I can still make an exception for SP1000 SS model which I can tolerate in my pocket. In terms of a design, both offer large internal storage, uSD expansion, large touch display, though SP1000 display is bigger and overall OS navigation is a little faster and more intuitive. WM1Z battery performance is by far superior. Furthermore, you have SP with a standard usb-C connection while 1Z uses a proprietary connector.

I got used to WM1Z navigation quickly, but out of the box it had a steeper learning curve. The volume knob of SP was also a plus for me since it’s faster to adjust vs buttons on WM1Z, but it’s an opposite with larger hardware Play/Pause/Skip buttons on WM1Z versus smaller identically shaped ones on SP. Difference between 2.5mm vs 4.4mm balanced connectors will have a polarizing effect since many people already invested into 2.5mm cables and will have to use either adapters or to re-terminate or to get a new cable. Direct Line Out and Digital (optical) Out is another advantage of SP over WM1Z, for those who want to pair up their source with external components without investing into adapters or dealing with docking stations.

Both offer Bluetooth connection supporting aptX and aptX HD for higher resolution wireless pair up, while WM1Z also supports Sony’s proprietary LDAC protocol if you have their wireless headphones. Neither one has Android OS with app support, but many audiophiles will prefer access to TIDAL offered by A&K, though you should keep in mind: no off-line storage/listening. Furthermore, WM1Z offers more sound-shaping options with a more practical EQ adjustment and other DSP effects. Overall, each DAP has its Pros and Cons, and none of them are showstoppers preventing a user from enjoying the best these DAPs have to offer in terms of sound and usability. It will all depend on user’s personal preference and which features have a higher priority. And, similar to flagship IEMs/headphones, you will have to choose your sound signature of preference for the best synergy with your favorite IEMs/headphones.

Here are more comparison examples of SP1000 vs other flagship DAPs. SP1000 SS had the latest fw 1.08.

SP1000 SS vs Lotoo PAW Gold – SP has a wider soundstage in comparison to LPG. In terms of tonality, SP is more neutral and transparent in comparison to LPG where tonality is smoother with noticeably more sub-bass rumble and stronger mid-bass impact, and more sparkle in treble. Both have a very dynamic layered sound, but SP has more transparency and a more neutral tonality, while LPG adds more punch and sparkle to the sound. Also, when it comes to sensitive iems, LPG has more hissing. In terms of usability, SP offers a significantly bigger touch screen display vs a much smaller non-touch LPG screen, and also offers access to TIDAL streaming, Bluetooth, and Optical digital out. Plus, LPG has no internal storage and uses SD card only. On the other hand, LPG has excellent Parametric EQ (one of the best) and a selection of DSP sound shaping effects, and overall, it’s a lot smaller and more pocket friendly.

SP1000 SS vs iBasso DX200 w/AMP4SP soundstage is a little bit wider, but DX200/4 is not too far behind. DX200/4 tonality is a little bit brighter and a touch rawer, while SP flows a little smoother in comparison. I wouldn’t say SP is warmer, it’s not, just a little smoother in comparison. One of the noticeable differences is the low-end response where mid-bass of DX200/4 punches through a little harder, while both have the same sub-bass rumble. And with treble, I hear more sparkle with DX200/4 while SP is more neutral in comparison. Both have a very dynamic layered sound, though SP is a little better when it comes to layering. Modular design of DX200 has an advantage of different sound sigs depending on amp module selection, where AMP4 (4.4mm module which unfortunately has been discontinued) elevates its performance to SP1000/WM1Z level. And it also has advantage of side-loading apks to run Play Store app. SP dedicated interface is faster and more responsive, while DX200 is relying on running full Android OS. Furthermore, SP offers more internal memory and has a more solid SS/CU chassis build. Also, SP has advantage of aptX HD. DX200 w/AMP4 is not going to destroy SP audio performance, but it can offer a great alternative if you are on a budget or want an additional DAP with a modular design and access to Android.

SP1000 SS vs theBit Opus#2 – Both have a similar soundstage expansion, maybe with SP being a touch wider, #2 doesn’t lack in soundstage width. Here, I hear Opus#2 having a little brighter tonality due to a higher energy in treble. In comparison, SP is smoother, more musical, and more neutral in tonality. They both have a dynamic expanded sound, but SP sounds more natural and more balanced in comparison to #2 which is a bit rough in treble area by comparison. Also, from a technical perspective, SP offers a better layering of the sound. Both offer a solid design, volume knob, similar playback hardware controls, optical digital out and 2.5mm balanced out, though SP has more internal memory. While Opus#2 can be side loaded with apps, it’s a cumbersome process since its Android OS is closed. aptX HD advantage of SP is a plus, as well as a robust TIDAL support for streaming. Similar to DX200 w/amp4, Opus#2 is another good alternative for audiophiles on the budget, especially after recent price drop.

SP1000 SS vs Cowon Plenue 2 mk2 – SP soundstage is wider, while I hear P2 with a little more depth. In terms of tonality, SP is a little smoother and more natural in comparison to P2 being a little brighter in comparison. They both have a very similar low-end response, while treble is smoother in SP. P2 mids are a little more revealing, but not as transparent or resolving as SP. Both have a good dynamic expansion of the sound, but SP sounds more natural, more transparent, with better layering and sound separation. I know, P2 is not Cowon’s top model, but I still consider it at their lower flagship level. Plenue has a compact size, and a very fast responsive OS and JetEffect dsp effects and semi PEQ, all of which are impressive. But it does fall a bit short in sound quality when compared to SP, and limited without access to TIDAL and no Bluetooth which SP does offer.

SP1000 SS vs FiiO X7ii w/amp3a – Right away you can hear a narrower soundstage expansion of X7ii in comparison to SP. SP tonality is smoother and more musical in comparison to X7ii being a little more revealing and rougher, though both are relatively neutral, just with X7ii having a little more energy in treble. Here, another noticeable difference, in addition to soundstage, is a vertical dynamics expansion of the sound which is by far superior in SP. I also hear a noticeable improvement in layering and separation of the sound when listening with SP. FiiO’s X7ii is their current flagship and does offer a modular design, similar to DX200. It also has an advantage of full open Android OS with access to Play Store and all the apps, but that’s about it since SP offers a superior audio performance and faster user interface, as well as more internal storage and aptX HD support. But nevertheless, I don’t want people to discount other manufacturers flagships which offer more budget friendly alternatives at a fraction of SP price, though you have to be realistic about their performance relative to SP.

Page 4 – Pair up with IEMs and Full-size headphones.

Page 5 – Wire and wireless connections, and Conclusion.

37 thoughts on “Astell & Kern A&ultima SP1000 SS/CU

  1. Interesting that the Plenue 2 Mk 2 has the same AK4497EQ dac as SP1000 but the SP has 2 of them! The EQ controls on the Plenue are really good. Maybe A&K will fix them on the SP with firmware updates since everyone is saying they have little to no affect.


  2. Hi Alex
    Have you had the chance to compare Dx200 and Amp8 with the Sp1000 ?. Since Amp8 is slightly better than Amp4 I’d like to know how you think it stacks up against the sp1000 . Thanks


    1. Yes, amp8 has a little better technical performance, but SPK still has this magic in tuning where the tonality just feels right. But of course, it lacks a lot of features of DX200 if you want streaming or app access or more audible eq adjustment or akm dac filters changes. But strictly based on tonality and sound performance, SPK still has an edge. I do have now DX200Ti, even better than DX200 😉 getting closer to SPK. For someone on the budget, DX200 is an excellent recommendation!


  3. Hello ,
    Wanted to ask you how would you compare SPK to the AK 380 ? I want to upgrade from my ak300 but I have a chance to get new ak380 for 1/3 of the price of the Spk. Is it worth it ? Or should I save more and get the latest flagship. What would be your take on it ?
    Thanks a lot


    1. sorry, no experience with ak380, and from what I read it’s not that great without add-on amp. If you want to save money over SPK, why not look into SPKM? It’s $1.1k cheaper, close in sound quality, smaller, and can support all the streaming apps, and I have no doubt spkm will be noticeably better than ak380.


  4. Hello,
    There is a promotion in my country on spk and sp1000M. Is it worth adding money to get the top spk ? I also want to use it as a file source in my home rig. I have an Ayon cd player but there is a coax and balanced input so I could use it as a DAC. What would you suggest in this situation ?
    Thanks a lot 🙂


      1. Hello ,
        Thanks , the pocket isn’t as important as ability to plug it to a stationary high end setup , so you think versitality wise there isn’t much difference between the two ?
        Also my IEM 64 audio U 18t are coming this week so I am also chose great setup for it.
        Thanks again


  5. Ok,
    That sounds great. Thanks for honest opinion !! :):):)
    Should I order a balanced jack ? Is that the cable you are using ?


    1. Always balanced and then you can get 3.5mm adaptor later, but yeah, get it 2.5mm terminated. But first, spend some time with a stock cable, get used to the sound. Figure out later if you even need an upgrade.


      1. Hello ,
        Thanks a lot. 🙂
        I saw on the AK site that there is a brass housing version of sp1000M. Any news on the sound of that one ?


  6. Hello,
    I finally have the sp1000 copper. !! With my 64 audio u18 it sounds fantastic !!! I have a question. What would you suggest in terms of burning the CD collection . Would you suggest getting the AK CD ripper or if not on a Mac how to burn the CD in a best quality to enjoy the sp1000 ?
    Thanks a lot 🙂


    1. I never used AK CD ripper, but maybe it’s not a bad idea. Laptops don’t come with CD drive nowadays. You will have to buy something external anyway. Might as well get from A&K since it should integrate nicely with SPK dap.


      1. I have no idea, never used it. I’m sure it comes with some instructions, or better yet, search YT for videos… When ripping CDs you have to convert to lossless CD-quality format which is 16bit 44.1kHz and save it in FLAC. Anything higher will mean the upsampling which going to make files a lot bigger in size and artificially adding bits that were not there before.


      2. Thanks
        I was asking more how do you transfer CDs into your sp1000? Do you use a program or how does that work for you best ?
        Thanks for your time


      3. in the past I used Windows Media player (but it’s no longer available with Win10). I’m sure you can google and find lots of different freeware and shareware programs.


  7. Twister6
    Have you had a chance to compare the effect audio Leo II with the original ?
    I have a possibility of purchasing the Leo original. And am wondering if that would be a good choice or would you advise to add cash and get a Leo II cable ( also second hand) ?


      1. Twister6
        I have the leo II and it is quite wonderful. The stage is great and the separation, but it is not forgiving on poor recordings. Than the sound is a bit sharp. To make this a perfect system would you advise an amp that would add more warmth to the sound especially to the midrange ? Would WA 8 be a good choice ? Or would you advise something else. ? I find the sound to be on the brighter side than normal termination but than the separation and stage are great .


      2. What iem do you have? You can fine tune with an even warmer cable, like OSLO, but I have a feeling it might not be enough. So, warmer tube amp is a good solution. Don’t have the experience with WA8, but heard it’s good.


  8. Just to clarify , with my sp1000 copper and 64 audio u 18t I am missing some ” slam” in the base depertment and a bit more body to the mids. :)thanks a lot


  9. Sorry
    It misspelled my name.
    I have so 1000 copper and 64 audio u18t. Like in the posts above.
    What would be your advise to get some extra warmth to the sound ? Or did you find your setup with u18t sp1000 perfect sounding without the amp ?


    1. Leo II was perfect for me w/SPK. What eartips are you using? If silicone, can you try foam tips? Maybe U18t is just not for you and you need more neutral warmer sig iems instead?


      1. Hello
        I use custom tips from custom arts . I did love the U12t they were more on my sound signature but the stage and resolution were much worse than the u18 t. And in more busy or classical music the u18 shine. With good recordings they sound fantastic but poor come off sharp a bit to me ‘(


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