Astell&Kern A&ultima SP1000 DAP

General Information

The A&ultima SP1000 is a one-of-a-kind, high-end,
powerful flagship high resolution music player equipped with the latest advanced features.

A true flagship high-resolution music player
First Astell&Kern player to feature an octa-core CPU for outstanding response and performance
High Definition HD5 display to create the best viewing experience
Innovative new Multi-function Wheel


Model: SP1000
Body Color: Onyx Black / Stainless Steel / Copper
Body Material: Onyx Black, Stainless Steel : Stainless Steel / Copper : Copper
Display: 5inch (720 x 1,280) Touchscreen
Supported Audio Formats: WAV, FLAC, WMA, MP3, OGG, APE, AAC, ALAC, AIFF, DFF, DSF
Sample rate: PCM : 8kHz ~ 384kHz (8/16/24/32bits per Sample) / DSD Native: DSD64(1bit 2.8MHz), Stereo
/ DSD128(1bit 5.6MHz), Stereo / DSD256(1bit 11.2MHz), Stereo
Output Level: Unbalance 2.2Vrms / Balance 3.9Vrms (Condition No Load)
CPU: Octa-Core
DAC: AKM AK4497EQ x2 (Dual DAC)
Decoding: Support up to 32bit / 384kHz Bit to Bit Decoding
Input: USB 3.0 Type-C input (for charging & data transfer (PC & MAC)) / Connection Mode : MTP (Media Device)
Outputs: PHONES (3.5mm) / Optical Out (3.5mm) / Balanced Out (2.5mm, only 4-pole supported)
Wi-Fi: 802.11 b/g/n (2.4GHz)
Bluetooth: V4.1 (A2DP, AVRCP, aptXTM HD)
Dimensions: 2.98 ”(75.8 mm) [W] x 5.2 ”(132 mm) [H] x 0.64 ”(16.2 mm) [D]
Weight: Onyx Black, Stainless Steel : 13.64 oz (386.6 g) / Copper : 13.68 oz (387.9 g)

Frequency Response: ±0.062dB (Condition: 20Hz~20kHz) Unbalance / ±0.061dB (Condition: 20Hz~20kHz) Balance: ±0.68dB (Condition: 10Hz~70kHz) Unbalance / ±0.67dB (Condition: 10Hz~70kHz) Balance
Signal to Noise Ratio: 120dB @ 1kHz, Unbalance / 122dB @ 1kHz, Balance
Crosstalk: 138dB @ 1kHz, Unbalance / 143dB @ 1kHz, Balance
THD+N: 0.0005% @ 1kHz, Unbalance / 0.0008% @ 1kHz, Balance
IMD SMPTE: 0.0004% 800Hz 10kHz(4:1) Unbalance & Balance
Output Impedance: Balanced out 2.5mm (1ohm) / PHONES 3.5mm (2ohm)

Battery Capacity: 3,700mAh 3.8V Li-Polymer Battery
Continuous Playback Time: Up to 12 hours (Standard - MUSIC: FLAC, 16-bit/44kHz, Volume 75, LCD Off)
Charge Time: About 2 hours (Standard - 9V/1.67A Fast charging)
Memory Built-in Memory: 256GB [NAND]
External Memory: microSD (Max 256GB) x1


Latest reviews


twister6 Reviews
Headphoneus Supremus
Pros: choice between two sound tonalities (SS vs CU chassis, at the same price), excellent build, large responsive touch screen, soundstage width, very transparent layered sound, TIDAL support, aptX HD, Fast charge, leather case.
Cons: price, weight, subtle PEQ adjustment, no access to AKM filters.

The product was loaned to me free of charge for the review purpose in exchange for my honest opinion. The review was originally posted on my blog, and now I would like to share it with my readers on head-fi.

Manufacturer website: Astell & Kern.



Prior to this review, the first and the last A&K DAP I had a chance to test was AK120ii. Now, 3 years later, I still feature it in majority of my reviews as part of pair up testing with various IEMs and full-size headphones, and in comparisons to other DAPs in a similar price/performance class. So, when my readers ask me why I still use AK120ii (I get that question a lot), the answer is because that’s the only A&K DAP I had access to and because it’s still relevant. The meaning of relevance in today’s DAP market feels almost the same as in smartphone market, and coincidentally has a lot to do with catering to streaming apps, Android implementation, and hardware to support it, which makes some DAPs obsolete in a short period of time after the release. A&K focus seems to be more on sound quality and user experience first, without worrying too much about general app support. That's how they keep OS lean, fast, and optimized. And even so they provide access to Tidal (current audiophile choice for streaming), we are not talking about open Android with a freedom to install other apps.

Recently, after getting the opportunity to spend a few months with A&K current flagship A&ultima SP1000, this DAP became a permanent fixture in all my latest reviews. I already posted a mini-review focusing on SP1000 SS vs CU comparison while I had CU unit on a short loan, and now I'm ready to share with everybody my thoughts about SS version. Just as a heads up, I can't comment on comparison of SP1000 to the previous AK380 flagship since I don’t have any experience with it. But you can certainly expect my usual detailed analysis of the design, user interface, sound performance, comparison to other summit-fi DAPs, and an extensive guide to pair up with many different earphones.

I find it very important in this review to be clear about which firmware version I’m using, thus I will be specific about it. According to the official statement from A&K, there shouldn't be a sound difference between firmware updates within each specific SP1000 model, and the sound should only vary between the models, such as SS vs CU. Personally, I do hear a difference between fw updates which I have described in my SS vs CU review, though I don’t have a definitive explanation why there is one and still wonder if it has anything to do with tweaking of AKM filters by manufacturer, which users don't have access to. But either way, let's take a closer look at what I’ve found after spending the last few months being permanently attached to this DAP.


Unboxing and Accessories.

I decided to combine these sections together since a big part of the unboxing is a beautiful wooden giftbox SP arrived in. Covering the wooden box, there is an all-black packing paper box with a signature "A" and Astell&Kern logo name on the front, and a detailed small print spec in 10 languages (including in English) on the back, plus a packing list of everything included. But the fun starts once you open the paper box to reveal a star of this unboxing - a wooden display giftbox.

It like how everything was packed inside of a wooden box with Astell&Kern name on the top cover. My only comment here, there is no latch or hinges to hold the cover securely attached, so be careful when lifting it up or moving it around, making sure to hold it from the bottom. Inside you have a foam cutout under the cover where you will find a leather case, and a foam cutout inside the main part of the box which holds SP1000 SS, quick start guide, warranty card, 2 sets of front/back film screen protectors, usb-C cable, and a neat SS pin for the uSD card tray latch release, designed in a shape of "A" logo. For sure, it felt like a premium unboxing experience, setting the tone for a flagship product waiting ahead of you.

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A-logo uSD tray pin was a nice touch, just be careful not to lose it. 2 sets of screen protectors were also thoughtful in case if you mess one up during installation or lift it up when sliding into a case. The included standard USB-C high speed cable for charging, data transfer, and usb DAC functionality is high quality, thick, with a durable shielding, and most likely with proper gauge wires. With a fast charge mode support, it's important to use a quality cable for high speed charging at higher voltage.

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As expected, A&K included a quality premium leather case with SP model. The case fits like a glove, with a generous opening for usb-C connector at the bottom, covered play/pause/skip buttons on the left (though a bit shallow when you slide finger over the case), a fully open top (where you slide the DAP in), and uncovered upper right corner going from the volume/power wheel and all the way up. Inside the case you have a soft suede material to protect DAP from scratches. The case looks great and gives this large size dap a more secure grip when handling it.

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But my favorite case for SP model is Artisan Series Patina leather case from Dignis. The quality of Dignis work and material selection needs no introduction. This new model for SP1000 comes in 2 finishes, navy and brown, and takes a long time for one craftsman to dye by hand to get a perfect aged patina finish. It’s often listed as out of stock because it’s a very time-consuming process, requiring the long wait until the next batch is ready.

Besides enhancing the grip and protecting the DAP from scratches and minor drops and bumps, the inner soft lining gives a nice cushion, there is one more advantage to this case. Like a stock case you have a generous usb-c port opening at the bottom, covered transport control imprinted buttons on the upper left side (though, easier to feel), and a large opening at the top where you slide the case in. But unlike a fully open upper right-side corner of the stock case, Dignis carefully crafted its design to cover the upper right part of chassis, protecting the DAP and avoiding the bend of the front upper corner of the case, plus having a neat cutout for the volume knob. You do have to be careful when sliding SP1000 in and out of this case, and should refer to the instructions provided by Dignis.

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A&K latest flagship is a big DAP in every sense of the word. It has a big sound, a big display, and it’s bigger in size. With dimensions of 75.8mm x 132mm x 16.2mm, on par with some of the large screen smartphones and a few of my other big size DAPs, I still consider it to be portable, but it might not be pocket friendly for everybody due to its 388g (Stainless Steel) or 418g (Copper) weight. This is just part of a tradeoff for having a large 5” high definition touch screen and additional weight associated with either SS or CU chassis.

The focus of the design is the large 5" touch screen occupying the front view, with a touch home button below the visible display area - a great feature to get back to the main Playback screen from any other screen. The front view of the DAP is nearly symmetric between the bevel sides, with a crown-patterned volume wheel on the right which also functions as a power button when you press on it. As a power button it has a typical functionality of short press to turn the screen on/off or a long press to turn the power on/off, with confirmation to shutdown which requires touch screen acknowledgement. The volume wheel is easy to turn using one finger, though it's not loose and has some resistance with a click action felt for every rotation turn.

A&K DAPs were always known for a physical volume wheel, but in SP1000 to improve the ergonomics they decided to combine it with a power button for an easy reach - a good idea considering large size of this device. Basically, you don’t have to take your hand/finger off the volume wheel after the adjustment if you want to turn on/off the display. The design of the volume wheel has a detailed crown pattern, typical of a wrist watch. It certainly adds to the appeal of the DAP, since even inside of a leather case the wheel is still visible.

On the left side you have Play/Pause and Skip controls, three little buttons located in the upper part of the left side. They do have a nice tactile response and spaced evenly with enough room in between to avoid pressing an adjacent button by mistake. Plus, Play/Pause has a bump for an easy id. The only problem, majority will have SP1000 in a leather case with buttons covered, and stock case has a shallow imprint where it’s not easy to id play/pause in the middle when quickly brushing your finger across. That’s why I liked a better definition of imprinted buttons in Dignis case.

The top of the DAP has fully open access to 3.5mm headphone port which also used for Line Out and Optical out, and 2.5mm balanced headphone port. Right next to it, there is a flush mounted micro-SD card tray which keeps the dust away and needs the included A-pin (or any other pin) to open it. I have seen other manufacturers starting to implement a similar micro-SD card tray design, but what I like here is that tray is accessible with a case on. This way you don’t need to remove a leather case to replace micro-SD card.

At the bottom you have USB-C port which is used for charging (including Fast Charging), data transfer, USB DAC connection, and USB OTG external device connection. Next to it there are docking contact pins for future A&K expansions. The back of the DAP has an asymmetric carbon fiber inlay and a small round cavity in the upper right corner used probably for securing of docking accessories. And of course, the metal chassis of the frame around the sides and the top/bottom are made of either Stainless Steel (SS) or Copper (CU) metal. I assume CU finish has some anti-oxidation coating.

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Under the hood.

While we can argue that it’s not the chipset but how you implement it that makes a difference, at the time of its release SP1000 was one of the first manufacturers to introduce the latest flagship AKM AK4497EQ DAC, using 2 separate DACs for the left and the right channels. A&K didn’t share any further details about the design of the internal headphone amp section, but certainly it’s more powerful from the balanced output in comparison to their previous flagships. While single ended output is still 2.2Vrms, balanced output almost doubled to 3.9Vrms, which roughly translates under 32ohm load to about 475mW of power. This is plenty of juice to drive even some of more demanding headphones which I’m going to cover in the pair up section of my review. I was also impressed with SNR spec of 122dB in balanced output which certainly reflects in improved dynamics of the sound.

The touch display is a very responsive 5” high definition (720 x 1280 resolution) screen. By smartphone standards this resolution is average, but considering this is audio only playback device, it’s more than adequate. The interface is very fast, thanks to octa-core CPU. I didn’t notice any lag, and the navigation and audio decoding was a breeze. You need this processing power to be able to get flawlessly through audio decoding while supporting all the popular lossy and lossless formats of WAV, FLAC, WMA, MP3, OGG, APE, AAC, ALAC, AIFF, DFF, and DSF, with PCM rates up to 32bit/384kHz and DSD rates up to 11.2MHz (DSD256).

And for high resolution files you have plenty of storage with internal 256GB of NAND flash storage and microSD external memory expansion up to the latest largest capacity card. Furthermore, USB-C OTG supports external hard drive storage or usb stick expansion. You also get a decent battery life, thanks to 3,400 mAh li-po battery where I verified 11hrs 45min playback time of mp3/flac files in a loop with a screen off using IEMs connected to 2.5mm balanced output. Of course, this is a best-case scenario, but that’s what I use in DAP comparison. Also, when you need to charge it back up, SP1000 now supports a Fast Charge which takes under 2hrs to get it from empty to 100%. You can either use a regular 5V/2A charger or a Fast 9V/1.67A charger.

To support fast charging and to speed up data transfer, SP1000 also features USB 3.0 Type-C interface for charging, data transfer, and USB DAC functionality. You still have WiFi 802.11 b/g/n (2.4GHz) support for OTA firmware updates and SPOTIFY streaming, and Bluetooth v4.1 Wireless supporting A2DP and AVRCP profiles, and aptX and aptX HD protocols. Also, in addition to 2.5mm BAL output, 3.5mm SE port is multifunctional for headphone out, line out, and optical digital out.

But probably the most impressive part of this spec is that A&K went from their previous AK380 flagship to SP1000 with an upgraded DAC (from dual AK4490 to dual AK4497EQ), higher balanced output power (from 2.2Vrms to 3.9Vrms), bigger display (from 4” 480x800 to 5” 720x1280), faster CPU (from dual-core to octa-core), faster USB data bus (from USB2.0 to USB3.0), and even faster charging (from general 5V @2A to fast charge 9V @1.67A), while the price remained the same. True, the price is still at a premium level, but this was a HUGE upgrade while the price didn’t change.



I’m often being asked why I go into so much details describing the GUI. I review a lot of products, including many DAPs, and often asked numerous questions after the review, days, weeks, and many months later. Sometimes I don’t have DAP in front of me at that moment, and it’s easier to “reach out” to my review if I don’t remember the answer off top of my head. Also, you can think of this GUI section as a user guide, to make sure you didn’t miss any hidden gems.

Once you press the Power-crown and after waiting for about 10sec as you are greeted with “A” symbol, you arrive at the Main Playback screen of the SP1000, also accessible by pressing a touch Home button at the bottom of the screen. Thanks to a large 5” display, there is plenty of room for a clear view of the interface with all the controls out in the open. The embedded artwork (with cover art) window occupies top half of the screen, tapping on it expands the view and shows lyrics if one is available. Swiping artwork window left/right skips to prev/next song in your playlist. Above it you get a summary of song format (file type, bit depth, and sampling rate), with a link to Now Playing (where you can edit/modify from within) in the upper right corner and a link to Navigation Menu in the upper left corner.

Right under the artwork window there is a thin strip of transport control to fast forward/back by swiping through the song. Of course, you can also do that by holding Next/Prev touch buttons or physical playback control buttons, but I have a feeling majority of users will probably prefer to take advantage of touch-swiping through the song. While this control strip is narrow and requires user to be careful where you tap, A&K came up with a clever way for you to see the current song position as you swipe by turning the whole artwork window into semi-transparent transport control and literally expanding the swipe area to the entire screen when you touch and hold it.


In the lower half of the screen you have a row of controls with a left arrow (taking you back to the current folder you are in, along with a storage info), ‘+’ to add to the playlist, ‘…’ with a link to a detailed ID tag song info, and two right-most icons to control the playback by selecting play all, repeat, repeat one, play through and random. The playback section also gets reflected in notification bar area of the DAP, all the way at the top. Below this row of controls, you have a song name with an artist and album name, and 3 playback touch buttons with Play/Pause in the middle and Skip Next/Prev on the sides. The buttons are large and adequately spaced so it’s easier to tap them.

The Navigation menu, accessible by pressing “A” in the upper left corner, takes you to a list with various Sorting option (song, album, artist, genre), Playlist, Folder view, MQS, CD library, Store access (Groovers+ and TIDAL), and Settings. You can also access this screen by swiping display to the right from the main Playback screen, where you can also swipe to the left and get into Now Playing screen. Under every sorting option you have other options to add songs to playback queue, different layout to view album (single, double, or triple columns), view artist with every album under each name, genres according to id tags, and my favorite Folder browsing which also gives you extra info about internal storage.

Settings menu is very important, but you can also access some of the shortcuts by swiping the screen down to see what’s available in Notification area where you can toggle Wi-Fi, Bluetooth, EQ, USB mode, external usb, AK connect, Line Out, Gapless, Wheel lock, and shortcut to the main Settings menu. Many of these toggle options don’t just enable the functionality, but if you long press on it – will take you to the menu of that functionality. In the main Settings screen you have Wi-fi, Bluetooth, AK Connect, then Equalizer, Gapless, Line Out, L/R Balance, Playback setting (location where you add the songs in now playing and other options to add a song), CD ripping (for external ak unit), usb mode (MTP or USB DAC output), usb audio (DSD converted to PCM or DoP), S/PDIF conversion (upon connection, enabling selection of bit depth and sample rate). Other options are DAP related, like brightness setting, date & time, device name, language, keyboard, Power settings (power, screen, sleep setting). And of course, Update, System Info, and Default settings reset.

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Despite AK4497EQ DAC support, access to DAC filters is not enabled. Would have been nice, but A&K is very specific about sound tuning of their DAPs. Another thing is EQ. One Pro EQ preset is available and it makes the sound smoother, making it more natural and more organic. Otherwise, there are no genre specific presets, but you can create your own ones. EQ interface is very polished and has two modes, Main and Advance. In the main mode you have standard EQ sliders covering 20 bands (30, 45, 60, 90, 120, 180, 250, 380, 500, 750, 1k, 1.5k, 2k, 3k, 4k, 6k, 8k, 12k, 14k, and 18k) where you can either slide the bar or use a more precise 0.1 adjustment of the gain, as well as scrolling through available frequencies. And as you adjust, it gets reflected in the lower right corner, showing you overall shape of the EQ. Switching to Advance, turns EQ adjustment into semi-Parametric with a full GUI view of the EQ shape where underneath you have FREQ band selection (a choice of only 20, thus it’s not fully parametric), Gain selection in 0.1 and even 0.01 micro adjustments, and Q bandwidth selection in 0.1 increment adjustments.

This semi-PEQ interface looks great and has a perfect layout, but the actual adjustment has a very subtle effect on the sound. I was a little puzzled by this, because +/- 5dB adjustment of any band (the slider range) should be more audible, but not in this case. I personally don’t use EQ, so it’s not a big deal for me, but if you are a frequent EQ user – please be aware.

The whole interface is very intuitive, has a very logical layout, and very easy to read and to navigate. I like the big display with its big control touch buttons and easy to read menus. I like Home touch screen button which always takes you back to the main playback screen, and I like the notification bar at the top with all the available info (volume setting, playback setting, enabled controls, battery icon with percentage indicator and time display), and I like shortcuts to the main controls once you swipe the notification bar down.

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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.

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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.

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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/AMP4 - SP 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.

Pair up.

Due to SP1000 SS soundstage expansion and its unique neutral signature with transparent revealing tonality, I was looking forward to hearing how it pair ups with many of my IEMs and some full-size headphones. I was especially pleased with SP treble control (in fw 1.08 specifically) which helped to keep upper end of many full size and iems under a smoother control. In each pair up I noted the cable, either balanced (BAL) or single ended (SE) connection, and the volume level. Keep in mind, balanced output of SP1000 model is 3.9Vrms (roughly 475mW based on 32ohm load), and because single ended output has less power, volume had to be pushed harder.

Beyerdynamic T5p 2nd gen (TWag v3 BAL cable, Vol 85) – nearly holographic soundstage expansion, in all 3 dimensions. The signature is very balanced with a natural tonality, deep sub-bass extension with an excellent textured rumble and punchy faster mid-bass impact, mids are natural, resolving, transparent, but a little on a smoother more organic side, not the usual more analytical side; treble has a great extension, crisp but not harsh or too bright, airiness is more under control here. A very natural balanced sound, probably one of the best pair ups with T5p2 I heard to date.


Audeze EL8C (stock SE cable, Vol 111) - very wide soundstage with a nice depth expansion as well. The signature is close to balanced w-shaped, though leaning a little toward v-shaped with bass and treble being a little more forward. Tonality is on a leaner more revealing brighter side, but under control without even a hint of metallic sheen which these are prone to. Bass has a leaner sub-bass and balanced punchy mid-bass, lower mids are lean, while upper mids are more revealing, brighter, micro-detailed; treble is very crisp and airy, but non-fatigue. Again, with a good control of treble these have a more natural revealing tonality.

Oppo PM3 (BAL OFC cable, Vol 85) - wide soundstage with a little more depth than width in stage expansion. The signature is balanced with a warm smooth and less resolving tonality. Bass has a very good balance between sub-bass rumble and mid-bass punch, though bass itself is not very fast and spills a little into lower mids which are on a thicker fuller body side. Upper mids are smooth, organic, warmer, clear but not very detailed. Treble is well defined but not as crisp or airy. It's a nice smooth warm laidback tonality, though not the best PM3 pair up I heard.

VE Zen (stock SE cable, Vol 108) - wide soundstage with lots of depth. A balanced signature with a natural detailed tonality, and a touch more emphasis in mids. Very good sub-bass extension with a nice doze of well controlled rumble without being too overwhelming, fast tight mid-bass (definitely more controlled than usual), leaner lower mids, organic detailed upper mids, and a nice well controlled treble sparkle. Here, Zen sounds a little leaner and tighter.

UM Mason V3 (stock BAL cable, Vol 71) - holographic soundstage expansion. A balanced sound signature, leaning a little more toward V-shaped due to mids being slightly pulled back, with a neutral and very natural tonality. Very deep textured sub-bass rumble with a fast and punchy mid-bass, very layered articulate well controlled bass. Lower mids are lean yet still with a nice body presence, upper mids have a great retrieval of details, with a very neutral, natural and smoother tonality. Treble is crisp, well defined, under control without being harsh or splashy, very natural and airy and with a great extension.


HiFiMAN RE800 (stock SE cable, Vol 86) - very wide soundstage expansion. V-shaped sound signature with a bright revealing tonality. Bass goes deep and has a thick texture; sub-bass is very analog like and mid-bass is rounded and hits hard. Lower mids are lean, lacking some body, while creating a dip to accentuate the bass; upper mids are clear, detailed, slightly pushed back, brighter and crisper. Treble is very crisp, vivid, revealing, and airy. I'm typically bothered by upper mids/lower treble of RE800 with other sources, while here it's a lot more tolerable and actually enjoyable because SP keeps treble under control.

HiFiMAN RE2000 (stock SE cable, Vol 87) - very wide soundstage expansion. Sound signature is more balanced with a fuller body and a more natural tonality. Excellent balance between sub-bass and mid-bass with a more linear rendition in comparison to RE800, sub-bass goes deep but not as thick, though still has an analog texture, mid-bass has a nice impact with a moderate speed of attack and decay. Lower mids are closer to neutral, with more body, upper mids are very detailed and natural in tonality, slightly pushed back but still balanced with the rest of the spectrum. Treble is crisp and very well defined without being too harsh or sibilant; nice treble extension with plenty of controlled airiness.

64 Audio Fourte (HSA RedCore BAL cable, Vol 62) - wide soundstage with out-of-your head expansion. Sound signature has a very distinct W-shape with a brighter tonality thanks to upper mids and lower treble. Bass is very analog-like and dynamic, deep sub-bass and well rounded mid-bass slam, but overall bass is a little slower and with a longer decay. Lower mids are fuller in body and upper mids have a good balance between natural and revealing tonality, not exactly micro-detailed but still with an excellent retrieval of details. Treble is crisp, on a brighter side, with a good extension and airiness, not splashy or harsh, but more vivid. I have to add that I’m using Symbio eartips here which add a little more body to the sound.

64 Audio U18t (EA Horus BAL cable, Vol 60) - holographic soundstage expansion. Very balanced sound signature with a coherent tuning of a more natural revealing tonality, a very resolving sound. Bass is tight and articulate with a deep textured sub-bass rumble and fast punchy mid-bass, all under control with a nice overall impact. Lower mids are close to neutral with a nice body presence, upper mids are very detailed, closer to micro-detailed level without being analytical, still have a natural tonality, layered and transparent. Treble is crisp and well defined, perfectly balanced without being too forward to rolled off, not harsh or splashy, yet extended and airy. In this pair up I hear a little more bass presence and more natural treble extension.


EE Legend X (stock Ares II SE cable, Vol 75) – nearly holographic soundstage expansion. L-shaped sound signature with a smooth natural tonality. Bass slam is huge with an elevated sub-bass rumble and fast analog-like quality mid-bass punch that hits very hard. Lower mids are neutral with a nice body presence, upper mids are organic, smooth, natural, and still very clear and detailed. Treble is crisp, brighter but not harsh, not super extended, but with a moderate level of airiness. Bass could get a bit overwhelming, and unfortunately SP EQ is not as effective to reduce it here.

Sennheiser IE800S (stock BAL cable, Vol 76) - holographic soundstage expansion. Slightly V-shaped sound sig with a natural revealing tonality. Deep sub-bass textured rumble, a rounded slower mid-bass punch with an overall analog quality smoother bass. Lower mids are neutral, a little leaner in tonality, upper mids have a natural tonality with an excellent retrieval of details. Treble is very crisp with a sharp definition, but not harsh or splashy, and with a controlled level of airiness.


Westone W80 (stock EPIC SE cable, Vol 63) - very wide soundstage expansion. Balanced sound signature with a smooth natural tonality. Deep textured sub-bass with a rounded slower mid-bass punch, analog textured less aggressive bass. Lower mids with a fuller body, a little north of neutral, and smooth natural clear upper mids with excellent rendition of vocals. Moderately crisp well-defined treble with smoother tonality and moderate airiness.

Westone ES80 (stock ALO Ref8 SE cable, Vol 88) - very wide soundstage expansion with a nice depth. Balanced sound signature with a more revealing natural transparent tonality. Deep sub-bass extension with a controlled rumble, punchy fast mid-bass, very articulate layered bass. Neutral lower mids with a good presence of body, very natural upper mids with an excellent retrieval of details. Crisp well-defined treble with an airy extension. Overall tonality is very transparent and natural.

CFA Andromeda (ALO Ref8 SE cable, Vol 51) - wide soundstage with more out-of-your head depth. More V-shaped fun signature with emphasis on bass and treble where mids are pulled a little bit back. Bass has a nice textured deep rumble with a strong mid-bass impact, where bass is not too fast or too slow, but well controlled. Lower mids are on a leaner side, while upper mids are more revealing, brighter, with excellent retrieval of details, but slightly pulled back presentation. Treble is crisp, airy, on a brighter side, nicely extended.

CFA VEGA (stock ALO spc BAL cable, Vol 59) – nearly holographic soundstage. V-shaped sound signature with a serious bass slam and sparkly treble where mids are a pulled back. Sub-bass rumble is deep but doesn't have as much impact as the hard-hitting mid-bass which slams hard and spills a little into lower mids which are still on a leaner side. Upper mids are clear, detailed, transparent with a brighter tonality. Treble is crisp, a little splashy, airy, extended. Here, bass definitely dominates the sound.

oBravo RA C CU (stock BAL cable, Vol 95) - holographic soundstage expansion on a level of open back headphones. The signature is a little more mid-forward with a very neutral super transparent tonality. Bass is extended, goes deep, but rather neutral, very articulate and multi-layered; lower mids are lean while upper mids are very transparent, layered, micro-detailed, a little colder, literally on analytical level, yet they are not bright or harsh at all. The same with a treble which extends pretty far, very crisp and sparkly, super resolving with a very vivid definition thanks to its 12k peak, but it's not sibilant or harsh or fatigue. The treble control of SP allows to exercise RA to its full potential without being harsh, while still retaining their super transparent tonality.


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.

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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.

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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!
I just received my A18t from 64 audio. I've been using it with iPhone 7+ and DF Red. Now I'm thinking that I'd like to get a dedicated DAP. With the firmware updates, is there any difference anymore between the SP1000SS and Cu? I'm thinking the SS will have the advantage of not developing the oxidation issues that Cu would likely have down the line. Also, it's a bit lighter in weight. What say you?
I found the sound signature did changed too with the new firmware update. Glad that I am not the only one :)
how does sound compare to the mojo? also, have you had a chance to test the futura se100?


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