Astell & Kern A&ultima SP1000 SS/CU

Wired and wireless connections.

Besides being a portable DAP, you can expand SP functionality as a transport to drive external DAC/amp, to use external AMP, or to turn the DAP into usb DAC. And of course, you don’t have to be limited to wired headphones, and can take advantage of Wireless Bluetooth connection. While WiFi is used for OTA (over the air) firmware updates, you also get access to TIDAL built-in app for streaming, though must be aware that off-line content is not supported. And, while you have plenty of internal storage and uSD expansion, you can also connect other external storage or use A&K own Connect server app to stream from your computer. Let’s take a closer look at these options.


Majority of my wireless headphones support aptX, and for this test I used Sennheiser Momentum 2 Wireless (M2W) and B&W P7 Wireless (P7W). For a wireless source comparison, I used my Note 4 (N4) aging phone which also supports aptX codec.

With either SP or N4 paired up w/M2W, I could cover a distance of about 56ft away from the source in the open area, suggesting there is no handicapping of wireless antenna performance like with some other DAP manufacturers who reduce the power to save battery. Also, between these two sources I hear the same tonality, though I can get headphones louder with SP1000 and hear a little deeper sub-bass rumble.

In the same comparison with SP and N4 paired up w/P7W, I could walk away 52ft from SP vs 44ft from N4. Surprisingly, SP1000/P7W pair up provided 8 more feet of coverage. I do hear the same identical tonality, while the only difference is that closer to the max volume on my phone the sound gets a bit distorted, while SP1000 can go louder without any distortion. I have no idea why, but that’s how I hear it.

While aptX Wireless test using SP1000 vs Note 4 was a good indicator that SP performs on par with my smartphone, I was curious to try SP aptX HD codec in comparison to aptX. Using Bluetooth Wireless cable which supports both aptX and aptX HD codec, I connected simultaneously to Note 4 (aptX) and SP1000 (aptX HD) for a/b comparison. With the same set of IEMs, I can hear a noticeable sound difference where aptX connection has a looser bass with less control, thicker lower mids, and less clarity/sparkle in treble. While aptX HD connection has a tighter and a more articulate bass with a better control, more neutral lower mids (in comparison), and better definition of treble with more clarity and sparkle. While I always looked at aptX as a step up from a regular Bluetooth, HD takes it to a whole new level.


External AMP pair up.

I always find this to be a very important test because DACs and internal headphone amp circuit are crucial part of the DAP sound architecture. Thus, I like to use my neutral/transparent E12A portable amp to hear how the DAPs internal amp colors the sound. Using Line Out (enabled in SP setting menu or from pull-down navigation shortcut menu), I connected and compared SP1000 with and without E12A amp. Directly from headphone output of SP, I found a noticeable improvement in soundstage expansion, considering that I was using SE output in both cases for a more consistent comparison. Also, the internal headphone amp in SP1000 has a little brighter and more revealing tonality; bass and lower mids are similar, while upper mids are more revealing and treble has more sparkle and improved airiness in comparison. You can certainly pair up SP1000 with different external amps to color the sound. And keep in mind, LO output volume is not fixed, you can adjust it from the DAP.


Digital/Optical Out (DAC/amp) connection.

For this test I was using Optical Out of SP1000 vs AK120ii connected to iDSD BL. With digital output you are taking DAC and amp out of the picture. Some people say, it doesn’t matter which DAP you are using as a digital transport source, but apparently it does make a difference. In both connections I heard a clean, transparent, and very dynamic sound with a very wide soundstage and no distortion. But, compared to 120ii, SP1000 has a lot wider soundstage, much better imaging, and better dynamics where in comparison, the 120ii with iDSD BL sounds flatter and noticeably narrower. So, even with the same high-quality DAC/amp, digital transport section has an influence on the sound.

Streaming from computer.

I remember using this with AK120ii as well, so it’s not only limited to SP1000. A&K provides a software called AK Connect, which requires user to install MQS Streaming Server program. Then, easily add folders on your computer you want to share, and from within SP1000 select your computer and navigate to stream/play the music. The sound quality was on par with the same songs stored locally on the DAP.


USB-C OTG connection.

Using a basic cheap usb-c OTG adapter off eBay (under $3), I was able to connect usb stick to expand the storage of the DAP. This could come especially handy when connecting external hard drive where you can use an adapter or connect it directly, depending on the cable.

USB DAC support.

Yes, you can also use SP as USB DAC which is an overkill, but could be convenient for some people. A&K provides all the necessary drivers, but I have an issue with a few of my Win7 laptops at home due to a security setting of my Windows version which is very picky about digital signature of installed drivers. Thus, I didn’t test USB DAC functionality, but well aware that others had no issues using it.


One thing that surprised me at first about SP1000 was how little sound tweaking it offers. Besides choosing a model based on a chassis material where sound tonality differs, you don’t have access to change AKM filters or to apply DSP sound effects or to select a genre specific EQ preset. Even PEQ makes only subtle changes in sound when being adjusted. But then I realized that I’m missing the big picture. Each SP1000 model has been already fine-tuned to its final sound perfection the way how A&K wants you to hear their flagship product. That’s why I feel it makes sense to approach DAP reviews by treating each one as a black box, focusing and describing what I hear, how it compares, and how it pairs up.

While some might argue SP1000 is targeted at “money is no object” audiophiles, to me it’s like a flagship IEM/cable where you pay a premium to squeeze out every ounce of sound performance. And just like with any piece of flagship gear in this hobby, you should expect diminishing returns going up the summit-fi food chain. But if you want a premium DAP with a solid build quality, a very transparent and layered sound with super wide soundstage expansion, a decent power output to drive even some of the more demanding headphones, a large responsive display so you don’t have to squint your eyes reading menus or artist/song name, and a Fast charging to get you up and running quickly – even a year after its introduction, SP1000 is still one of the top choices to consider!


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 ‘(


Leave a Reply to Dariusz Kawulok Cancel reply

Fill in your details below or click an icon to log in: Logo

You are commenting using your account. Log Out /  Change )

Google photo

You are commenting using your Google account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s