Astell & Kern A&ultima SP2000T Tube / Solid State Music Player (MQA, Triple AMP, LDAC, Hi-Res, DSD, 5GHz Wifi)

General Information

Astell & Kern A&ultima SP2000T


Staying true to our philosophy of delivering original audio experiences without compromise, Astell&Kern strives to design portable music players that reach beyond the capabilities of a standard playback device to enhance the listener’s music enjoyment.

The SP2000T combines the OP AMP configuration of our SP2000—the culmination of Astell&Kern's finest audio technology—with a nostalgic vacuum TUBE AMP, adding a vintage feel to the portable player.

The Triple Amp System Takes Acoustics to a New Level

Vacuum Tube Amplifier Compatible with 2.5mm, 3.5mm and 4.4mm Output Jacks

Equipped with ESS ES9068AS QUAD-DAC, for Balanced, Ultra Detailed Sound

TERATON ALPHA, Astell&Kern's
Ultimate Sound Solution

Replay Gain Function to Maintain Consistent Playback Levels between Tracks

Dual-Band Wi-fi
Support for Uninterrupted Wireless Connection and Improved Compatibility

Internal Mechanical Design to Minimize Noise

Introducing the A&ultima SP2000T, the Ingenious New Solution.

"T" in SP2000T​

The "T" in SP2000T does not stand for a specific word, but rather encompasses design approaches and directions made during the product development process.


Triple AMP System is the Next Generation of AMP Technology​

The SP2000T exceeds the standard approach to AMP Mode selection, based on the type of music you are listening to.

Select between TUBE AMP mode, OP AMP mode or the brand new HYBRID AMP mode.

OP AMP mode puts Astell&Kern's AMP technology expertise to use, delivering extreme clarity and dynamic sound, while TUBE AMP mode provides a uniquely warm and musical sound.

HYBRID AMP mode - a first for digital audio players - enhances the resolution and clarity of the existing TUBE AMP mode to express more musical detail. HYBRID AMP mode combines the advantages of retro analog performance and high-resolution output, giving you the pleasure of a brand new tonal characteristic.

Experience the unique sound enhancements that AMP technology has to offer.


Vacuum Tube Amplifier Compatible with 2.5mm, 3.5mm & 4.4mm Output Jacks​

The SP2000T supports all output types, with no restriction on the type of receiver used, so you can enjoy the unique characteristics of the vacuum tube.


Real Vacuum Tube​

Equipped with the portable-friendly dual-triode KORG Nutube, for a unique TUBE AMP sound.

Nutube offers a reliable continuous playback time of approximately 30,000 hours.
It features an anode grid filament structure which operates the same as a triode vacuum tube.
It's much smaller, consumes far less power and yet delivers the same audio with rich overtones.

Hybrid AMP Mode​

HYBRID AMP mode, supported for the first time by a DAP, is the essence of Astell&Kern's advanced AMP design technology.

New combinations of sounds can be enjoyed in HYBRID AMP mode, which is based on the OP AMP sound and addition of tasteful warm tones unique to TUBE AMP technology.


The five options mixed and matched with optimal ratios of the OP AMP and TUBE AMP present users with a new perspective and choice for the perfect sound characteristic to suite their tastes.

Internal Mechanical Design to Minimize Noise​

Special Design to Minimize Microphonic Noise

SP2000T features a special design tailored to minimize microphonics (the phenomenon wherein the vacuum tubes generate noise even from a small external impact).

Multiple design iterations and verifications have been performed over a long period of time to fix the structural issues of vacuum tubes that generate microphonic noise even from a small impact or vibration.
For minimization of mechanical impact and vibration, both sides of the vacuum tube are fixed with flexible silicone covers, and the vacuum tube has been modularized so it is physically separate from the PCB.

Astell&Kern goes to great lengths to innovate and design these small components that make a big difference in the quality and sound of our products that no other manufacturer can match.

Separation Using Magnetic Polarity


A structure that uses magnetic forces to float the amp in the air, thus minimizing noise from the vacuum tube itself, which is generated when it is exposed to mechanical impact or vibration.

Flexible Silicone Covers


Silver Plating Shield Can


Astell&Kern products apply shield cans so that noise and electromagnetic interference, which occur when the countless parts are in operation, do not affect the audio block.

The SP2000T has taken it a step further by applying highly conductive, hyper-pure silver plating on the existing shield cans for perfect shielding that provides excellent audio performance.

Astell&Kern Audio Technology Forms the TERATON ALPHA Sound Solution​



TERATON ALPHA is AK's ultimate Sound Solution to produce audio playback that is close to the original sound through the audio output interface by use of effective power noise removal, efficient power management and amplification with minimal distortion.

TERATON ALPHA features Astell&Kern's patented technologies, which are the result of tens of thousands of hours of continuous research and development to produce sound close to the original sound the artist and producer intended.

Learn more about TERATON ALPHA >>

Adoption of Full HD Display for Improved Image Quality​

The SP2000T features a full HD screen to provide a higher quality display.


Quad-DAC for Perfection of Superior Sound​

The SP2000T is equipped with four ES9068AS DACs, this allows two DACs per channel for dedicated decoding.

The SP2000T achieves a more detailed and balanced sound with great depth and spatial realism.


Replay Gain Automatically and Uniformly Adjusts Playback Volume​

Replay Gain, which adjusts sound sources with different volumes to an identical level, has been applied.

Now, enjoy your own playlists seamlessly through the Replay Gain feature on the SP2000T.


*Replay Gain supports up to 24-bit/192kHz sound sources.

Dual-Band WiFi (2.4/5 GHz)​

Dual-Band Wi-Fi is supported for users who enjoy streaming services, providing enhanced network performance.

With streaming music services becoming more popular, stronger and more reliable network reception becomes even more important for your audio experience.

The SP2000T supports Dual Band Wi-Fi (2.4/5GHz, a/b/g/n/ac).

AK File Drop to Enjoy Wireless Transfers​

The new AK File Drop function in the SP2000T makes file transfers easier and more convenient.

Using AK File Drop, you can freely transfer files wireless through a PC, smartphone, or FTP program located on the same network.

Music file management is now possible with a cableless, wireless solution.

Wireless Hi-Fi Sound Through BT Sync​

The newly introduced BT Sync function connects the SP2000T to an external device via Bluetooth, similar to connecting a smartphone with a BT speaker.

Music from an external device, such as a smartphone can now be played back in high-quality on the SP2000T using the BT Sync function.

Real-Time Playback and AMP Mode Information Reflected by Light

Through the softly dispersing LED light, users are notified of the bit depth information of the song being played or the current AMP mode.


*LED light may be turned on or off in the user settings, and one can choose between the sound source information or AMP mode information displays.

Latest reviews


twister6 Reviews
Headphoneus Supremus
One, Two, Three!
Pros: triple-amp mode with variation in tonality between solid state and tube amps, solid build, hi-res 5” display with double-tap to wake, 2.5mm/3.5mm/4.4mm phone outputs, MQA, DSD512, LDAC Bluetooth (both Tx and Rx), 256GB internal storage.
Cons: larger size, battery life, some EMI interference in tube mode while streaming.

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

Manufacturer website: Astell & Kern. Available for sale directly or from on-line retailers like Bloom Audio.


The previous A&K release of SE180 with a modular dac/amp design caught everyone by surprise, though it made perfect sense as the next logical step after SE200 dual dac/amp design. It was also great to see 4.4mm BAL and LDAC making its permanent stay. Then, in anticipation of what could be next, some were speculating about the next A&K flagship. But nobody in their wildest dreams predicted the release of SP2000T (2kT).

Actually, 2kT announcement created a bit of a confusion for some because Astell & Kern usually adds a suffix letter to their model numbers with different chassis material or scaled down version rather than all new design like this “T” variation. Here, we got One DAP with Two amps and Three amplifier modes: a solid-state amp, a tube amp, and a hybrid with a mix of both. And as the cherry on top, the price is $1k less than original SP2000.

After spending some time testing SP2000T, here is what I found.


Unboxing and Accessories.

2kT unboxing experience is identical to other flagship SP DAPs. Don’t expect big surprises, though it is still impressive to see a premium quality “cigar” wooden storage box emerging from an all-black cardboard outer box. The outer box cover had a signature bold red “A” letter on the top and a detailed spec printed in 10 languages on the back.

Everything was packed neatly inside of that wooden storage gift box. And I still encourage to hold it from the bottom when lifting the top because there are no latches or hinges for the cover to keep it securely attached. Inside you have a foam cutout under the cover where you will find a leather case, 2 screen protectors, quick start card, and a warranty card. The foam cutout inside the main part of the box holds 2kT and USB-C cable.


Inside, I also found a storage card with a pocket and microSD card slot cover (plastic dummy microSD card), though another one was already inside 2kT, a bit of an overkill since the leather case already covers the slot. 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 adequate gauge wires. With a fast charge mode support, it's important to use a quality cable for high-speed charging at higher voltage.


Just like with other flagship SPs, A&K included a premium quality leather case for 2kT model. This one had “aged” yellow mustard color. The case fits like a glove, with an opening for usb-C connector at the bottom, covered play/pause/skip buttons on the left, generous phone ports opening at the top, covered power button at the top right, and generous cutout for volume wheel on the top right-side. The leather case design was updated where DAP slides from the left, and the side flap tucks in securely inside, providing a better protection from the top and corners. The case gives this large size dap a more secure grip when handling it. The only thing is microSD card slot being covered at the bottom, so you have to remove the case to physically access it.



Despite being the biggest SP-series DAP, with dimensions of 141.1mm x 78.1mm x 17.5mm, 2kT in onyx black finish with aluminum chassis is one of the lightest (309g) among full size SP2000 and SP1000 units, not counting SP1000M smaller version of SP1000. While being 100g lighter than SP2000 SS/CU, the use of aluminum really does help in comparison to heavier Stainless-Steel and Copper versions.

SP2000T vs SP2000 SS

The focus of the design is still around 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, especially since Navigation playback bar (like in SE180) is not available here. The front view of the DAP is slightly asymmetric due to uneven sculptured bevel sides, and a crown-patterned volume wheel. Unlike other SP models, volume wheel here doesn’t have power button functionality. Instead, a power button is at the top on the right side, like in SE180 and SR25, with a short press to turn the screen on/off and a long press to turn the power on/off followed by 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 with every rotation turn of 150 volume steps. And while it was convenient in SP2k where you didn’t have to take your hand/finger off the volume wheel after the adjustment if you want to turn the display on/off, 2kT implemented double-tap to wake up screen. The design of the volume wheel has a detailed crown pattern, typical of a wristwatch. It certainly adds to the appeal of the DAP, since even inside of a leather case the wheel is still visible. The design pattern of the 2kT wheel is different from SP2k and other A&K models.

On the left side you have Play/Pause and Skip controls, three identical small rectangular 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. Since majority of users will have 2kT in a leather case anyway, buttons will be covered, and stock leather case has their imprinted functionality label for easier ID. I’m sure we are probably going to see other aftermarket leather cases soon.

The top of the DAP has access to 3.5mm phone output port which also used for Line Out and Optical out. Next to it, you have 4.4mm and 2.5mm balanced phone ports that could also be configured for corresponding Line Out. All the way to the right you will find a power button. At the bottom to the right, you will find a spring-loaded microSD card slot. In the middle, there is USB-C port, used for charging (including Fast Charging), data transfer, USB DAC connection, and USB OTG external device connection for digital audio out. If you are using stock leather case, as already discussed, you will have to remove it to access microSD card.

The back of the DAP also has a typical A&K asymmetric design with about 3/4 of the back panel covered in aluminum chassis and the top quarter having a carbon fiber inlay under the glass. But as soon as the power is on, you will see a multi-functional and multi-colored long LED strip in the top area, shining through CF. In Setting, you can configure LED to display playback mode (red - 16bit, green -24bit, orange - 32bit, purple - DSD) or AMP mode (red - normal, orange - tube, blue-green - hybrid).


It is always cool to see multi-colored LED implementation in A&K DAPs, and the design of the case has a cutout on the back for a clear visibility. When I first saw that LED, I thought to myself maybe it was related to NuTube lights. Then, I realized it was a whole LED strip, and when I have 2kT on the desk next to me, I can’t see it anyway. And even when carrying 2kT with me, I don’t normally flip it over to look at LED light. It’s a cool design element, but its placement on the back hides the visibility under a normal use.


Under the hood.

After the last year AKM factory fire and current shortage of chips, a lot of manufacturers started to implement other DAC chips. In 2kT design, A&K implemented 4 separate ES9068AS ESS SABRE 2-channel audiophile DACs. This way they have full control and separation of balanced and single ended outputs. And if you look closer at the design diagram shared by A&K, you will see that 2.5mm and 4.4mm balanced outputs have separate paths, routing the signal with a number of audio switches. The single ended 3.5mm PO has output impedance of 1ohm and max output of 3Vrms, while balanced 2.5mm and 4.4mm, each have output impedance of 1.5ohm and max output of 6Vrms.


The touch display is 5” HD with a higher than SP2k resolution of 1920x1080 and impressive 441 PPI with 16.7M colors. The interface is relatively fast, thanks to octa-core CPU, but it is not on the same level as some of the recent Android DAPs with 660 SoC. Still, 2kT has plenty of processing power to do flawless audio decoding while supporting all the popular lossy and lossless formats, such as WAV, FLAC, WMA, MP3, OGG, APE, AAC, ALAC, AIFF, DFF, and DSF, with PCM rates up to 32bit/384kHz and DSD rates up to 22.58MHz (DSD512). Also, MQA playback support, covering Tidal Masters, Local files, External USB, and MQA-CD (ripped).

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 (A&K tested with 1TB). Furthermore, USB-C OTG supports external hard drive storage or usb stick expansion. The battery life is OK, not bad considering quad ESS DAC design and NuTubes. With 4200mAh (3.8V LiPo battery), you can expect up to 9hrs from unbalanced output and normal solid-state amp. Going to balanced and switching to hybrid mode will decrease that and going to more demanding DSD will reduce it even further. But with fast charging, you can be up on your feet within 3.5hrs.

To support fast charging and to speed up data transfer, 2kT uses USB 3.0 Type-C interface for charging, data transfer, and USB DAC functionality. WiFi is dual band, supporting both 2.4GHz and 5GHz. Along with that you have OTA firmware update support and of course streaming of many popular apps. Furthermore, Bluetooth is up to 5.0 with a wireless support of not only aptX-HD but also LDAC protocols, plus both Bluetooth Rx and Tx.

Of course, dual amplifier configuration is the key feature of 2kT design which gives you 3 amplifier modes. 2kT has solid state amp, called OP amp which has the same config as SP2000 DAP. Then, you have Tube amp which utilizes a single Korg NuTube 6P1 module that goes to all three phone outputs (3.5mm, 2.5mm, and 4.4mm). The third mode is Hybrid, a combination of both OP and Tube amps. You can vary the amount between OP and Hybrid and also between Hybrid and Tube.



When it comes to A&K DAPs user interface, once you get familiar with one, you will feel like at home using all of their DAPs. Basically, they all share the same interface, even SR25 with its smaller display uses the same GUI, scaled down to fit its smaller screen. I was a little surprised after powering up 2kT because I expected the same Navigation Bar as in SE180, but it was back to a typical SP2000 display layout, including a touch home button underneath the screen. But one new addition I noticed while running apps, when you swipe down Notification bar you will see open apps and can control the playback from there. The Floating Back button is still here as well and can be easily disabled by dragging it to the middle of the display or disabled in the Settings menu under Input Method. The button itself could be moved to anywhere along the left/right sides of the screen.


Once you press Power button, you are greeted with “A” logo and arrive to the main Playback screen. 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 it. And in the lower half of the screen, you have a row of controls, additional song info, and playback touch buttons.

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, Services (streaming), 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 id3 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 bar area where you can toggle Wi-Fi, Bluetooth, AMP mode, USB mode, External usb, AK connect, EQ, Line Out, ReplayGain, and shortcut to the main Settings menu. Many of these toggle options don’t just enable the function, but if you long press it will take you to the menu of that function. In the main Settings screen, you have Wi-fi, Bluetooth and Codec selection, AK Connect and File Drop, then Equalizer, Gapless, Line Out, L/R Balance, Playback setting, ReplayGain, Notification Panel, AMP mode, CD ripping, USB mode and audio, S/PDIF Conversion, Car mode, DAC filter (3 digital filters), and lots of other settings including Double-Tap Screen to Wake enable and LED config on the back

With EQ, you have one blank EQ preset and no other genre specific presets. EQ interface has two modes: Main and Advance. In the Main you have standard Paragraphic EQ sliders for 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 precise 0.1 adjustment, as well as scrolling through available frequencies. As you adjust, it gets reflected in the lower right corner, showing the overall shape of EQ. Switching to Advance, turns EQ adjustment into Parametric EQ with a full GUI view of EQ shape where underneath you have FREQ band selection (a choice of 20), Gain selection in 0.1 and 0.01 steps, and Q bandwidth. Since bands frequency is fixed, I consider this to be semi-Parametric EQ. The interface looks great and the actual adjustment has a noticeable effect on the sound.


While Navigation playback bar (like in SE180) wasn’t available in 2kT, there are a few other goodies added in this new SP series DAP. You get ReplayGain, though for now applicable only in 24bit/192kHz or less format, which could be set across either Tracks or Albums. Obviously, AMP Mode setting will give a choice of which mode you want to use, but no selection of normal or high gain. And my favorite, Double-Tap Screen to Wake, which is quite effective when 2kT is on the desktop and you don’t have to reach out for a power button to turn the display on to skip or navigate.

Open APP Service.

Open APP Service is implemented in all A&K Android based DAPs, including SP1000 SS/CU, SP1000M, SE100/180/200, SR25, and SP2000 SS/CU, and of course SP2000T. More info could be found here where Astell & Kern goes into details about how to install and to use it.

When you start dealing with Android apps, in many cases you do need a Back button for navigation, so Floating back button come in handy when dealing with streaming apps. While Astell & Kern offers a built-in Tidal service (without off-line storage support), for a long time their customers been asking to add Spotify, Qobuz, Amazon and other streaming services. A&K latest DAPs do run on Android, but it's a heavily modified closed OS without access to Google Play. In a way, it's a blessing for a manufacturer to keep DAP performance optimized since you don't have to worry about customers installing and running other unstable apps.

If you decide to install a non-blacklisted app, you need to download APK file (use a site like, copy it to Open Service Folder located on internal storage, go to Services on the DAP, and when you see the app being recognized and listed in there, click to install it. Keep in mind, for example, you will have to install Tidal apk if you want off-line downloads. Also, installed apps will not be updated automatically since you are not running Google Play. You will have to keep track of app updates and manually download and install new versions.


Sound Analysis.

The sound analysis of 2kT was done using Oriolus Traillii, playing a selection of test tracks, such as Agnes Obel “The curse”, Sandro Cavazza “So much better” (Avicii remix), C-Bool “Never go away”, Ed Sheeran “Shape of you”, Alan Walker “Darkside”, Galantis “Hunter”, Iggy Azalea “Black widow”, Indila “Boite en argent”, Dua Lipa “Love again”, Counting Crows “Big yellow taxi”, David Elias “Vision of her”, and Michael Jackson “Dirty Diana”. I had about 100hrs of burn in time before I started analyzing 2kT.

I prefer to describe the DAP sound based on the comparison to other DAPs and pair ups with different IEMs/headphones since the DAP by itself doesn’t have a “sound”. What we hear is how it sounds through connected IEMs/headphones or the difference in sound relative to source comparison using the same pair of IEMs/headphones. This is my subjective opinion, describing how I hear it while analyzing the sound of 2kT, and you will get a better picture in the follow up sections of Comparison and Pair up. Here, I would like to talk more about the different AMP modes, and how they compare.

I found the overall sound tuning of 2kT to be more neutral, natural, and balanced. Of course, you would expect that from Tube and Hybrid outputs, but even with OP (solid stage output) I heard a more natural tonality. When comparing OP vs Hybrid vs Tube amp modes, I hear the same technical performance, soundstage, layering, separation, and dynamics, while the main difference is between the speed of the bass and the body in lower mids.

In more details, OP (solid state) mode has a faster, tighter bass with a little better articulation and mids with a leaner body and more transparent tonality. Tube (NuTube) mode has a little slower, more relaxed bass and fuller body mids with a smoother warmer tonality. Hybrid (in the middle) mode has a combination of both, with a faster and more articulate bass and smoother mids with a fuller body which sound somewhere in between OP and Tube. The intermittent steps, two steps between OP and Hybrid and between Hybrid and Tube, to my ears have a hardly noticeable change in sound.

I know it’s a bold statement to make, but the difference in tonality between OP and Tube modes reminded me a lot of comparison between a typical Astell & Kern SS (OP) and Cu (Tube) tuning of other SP flagship DAPs.

2.5mm/4.4mm (BAL) vs 3.5mm (SE)

The difference in power output here is noticeable when going from SE to BAL where I always have to lower the volume to compensate for the difference in output power. Another noticeable difference is BAL output having a wider soundstage and slightly blacker background. Other than that, the sound signature, tonality, and even technical performance are nearly the same.


In every comparison I used Oriolus Traillii, volume matched while listening to the same test tracks between DAPs. Also, I only covering the difference in sound as I hear it, not the design and other functionality.

SP2kT vs SP2k SS - There are some technical differences such as 2k having a little wider soundstage and slightly better dynamics and layering of the sounds, but the bigger difference is in tonality. 2k is more revealing, brighter, more micro-detailed and with a little more sparkle. In contrast, 2kT has a smoother and more natural tonality, a little more coloring without compromising too much of detail retrieval. When comparing to OP, the gap is not that big. Switching to Hybrid/Tube widens a tonality gap a little more, still not night and day, but it is more noticeable.

SP2kT vs SE180/ESS and w/ Cayin C9 - Comparing 2kT to SP180 (SEP1/ESS), 2kT has a wider soundstage and better vertical dynamics of the sound. 2kT OP mode is a little more transparent and less colored, while Hybrid/Tube mode matches closer a warmer tonality of SE180. Adding C9 into the equation is not exactly the same as 2kT because C9 has dual fully balanced NuTube output, but it was worth a shot. One difference I did notice is soundstage being wider with SE180/C9 which is mostly likely due to dual-NuTube config. 2kT wasn't too far behind, but C9 output was wider. The overall tonality was very similar, just a little more sparkle with C9 output, but other than that the tonality was quite close. Vertical dynamics of SE180 w/C9 also got closer to 2kT level of performance, not the exact match, but very close.


SP2kT vs L&P P6 Pro - Some might wonder why would I be comparing these two DAPs, one being android based with app support while other is audio playback only with R2R DAC and more minimalistic interface? Well, in Hybrid/Tube mode the natural tonality of 2kT reminded me a lot of P6 Pro. Perhaps, P6 Pro has an upper hand with a technical performance, wider soundstage and a little more resolution and some improvements in dynamics, but they do share a natural organic tonality.

SP2kT vs Sony WM1Z (vinyl processor on) - I had a few people asking me about this comparison, especially with vinyl processor effect enabled on WM1Z. Technical performance between these is not too far off, maybe with WM1Z having just a touch wider soundstage. The tonality is where I hear a lot of difference. WM1Z bass is a little more aggressive, stronger, while 2kT is softer, especially the attack of the bass. Mids are a little brighter in WM1Z and so does the treble, while 2kT mids are smoother and more organic in comparison; the same with treble, 2kT has a bit smoother treble. But there was one peculiar difference that stood out for me. WM1Z has a blacker background which turns its warmer tonality into more digital sound, while 2kT has a dark background as well, but not as black, and that creates a more analog smoother sound, more appropriate for "Tube" output.


Pair up.

Here is how 2kT pairs up with some IEMs and headphones. In each pair up I noted either SE or BAL connection and the volume (V) setting.

Audio-Technica ATH-R70x (SE, v110) - very open and effortless sound with a balanced signature and natural transparent tonality. In OP mode mids sound a little thinner, while Hybrid/Tube has a similar tonality with a full body and a little warmer mids. Nothing is over-emphasized; the sound is very natural and with excellent retrieval of details. Bass is a little more neutral, giving more room for vocals to shine, but I still find the overall signature to be relative balanced and 2kT has not issue driving R70x.

Beyerdynamic T5p 2nd (BAL, v72) - in this pair up T5p2 sound like open back headphones, the sound was very open, did not even feel like I was wearing closed back headphones. The sound sig is closer to balanced as well, with tonality being a little more revealing but still closer to natural. Bass has a good tight punch, mids are transparent, even when I switch from OP to Hybrid/Tube, vocals didn't feel colored, though I enjoyed extra body in sound. Treble has a natural sparkle, T5p2 can get bright in upper frequencies, while here it stayed natural and revealing.

Meze Audio Empyrean (BAL, v83) - open sound with a soundstage that has a lot of depth/height, a little less width. The sound signature is balanced, and tonality is natural and smooth. Bass has a nice deep rumble, mids/vocals are clear, detailed, and has a little bit of warms, especially in Hybrid/Tube mode. Treble is clear and natural as well. The overall sound is very soulful and smooth, yet still with a good retrieval of natural details.

I enjoyed pair up with all 3 headphones, preferred Hybrid/Tube modes, and was actually a bit surprised, in a good way, about pair up with T5p2 that sounded quite natural and very open-back like.


CFA Solaris '20 (BAL, v37) - first of all, zero hissing. Soundstage expansion is pretty wide, and I hear a balanced sound sig with a little more focus on mids. The bass is above neutral with a good extension and tight mid-bass punch, sub-bass is there, but I'm hearing more punch than rumble. Mids/vocals are very clear, detailed, natural. Treble is crisp and has extra sparkle, good upper end extension with plenty of air, not harsh. The sound is a little more revealing, but at the same time non-fatigue. Hybrid/Tube mode adds a little warmth and body not only to the lower mids, but also a bit of extra weight to the bass.

UM Mest MKII (BAL, v59) - the sound in this pair up is almost holographic. The sound signature was v-shaped with more emphasis on bass and mid-treble. I preferred Tube more in this pair up. OP/Hybrid were OK, but they didn't bring as much weight and impact to the bass as Tube mode, giving Mest more rumble and stronger punch. Mids are smooth, natural, warmer, and slightly pulled back in their presentation. Treble is crisp, detailed, airy. Treble does have a little extra energy, not exactly smooth, but it wasn't too bad.

Empire Ears EVO (BAL, v59) - the soundstage here also approaching holographic level, especially with mids/vocals being a little more out of your head. The sound signature is more U-shaped with a lean toward L-shaped due to extra emphasis on bass and upper mids. Bass is big and bold, with a very strong and slightly hollow mids-bass punch. Lower mids are leaner while upper mids are detailed, natural, layered; treble is also detailed, natural, extended. Bass and treble are definitely stars of this tuning, mids are lagging a bit behind.

Empire Ears Odin (BAL, v57) - excellent soundstage expansion in all 3 directions. I preferred switching to Tube mode in this pair up, not even Hybrid, because it gave the bass deeper rumble and more weight, and lower mids gain more body which gave vocals more organic tonality. The only positive about OP pair up is a wider soundstage expansion while Tube output shrinks it a bit, giving the sound more depth/height than width. But this trade off was well worth it because of improvements in low end and in mids. Not even a hint of hissing.

64 Audio U18t (BAL, v59) - the soundstage in this pair up has more depth/height than width, but width is also above average. The sound sig is leaning more toward being mid-forward due to more neutral bass, and tonality is more revealing and a little brighter. Bass has a good extension and a tight punch, but both sub-bass and mid-bass are closer to neutral in quantity. Mids are lean, layered, resolving, crystal clear and detailed. And the same with treble, crystal clear and detailed without being fatigue. I preferred Tube mode in this pair up which gave bass a little more weight.

Oriolus Traillii (BAL, v59) - very nicely expanded soundstage in all 3 directions. The sound signature is balanced with a natural detailed tonality. Bass has a deep extension with a smooth warm rumble and mid-bass has a tight fast punch. Mids/vocals have a very natural detailed tonality, especially comes to shine in a Hybrid mode which I preferred in this pair up. Treble is crisp, detailed, and still natural and non-fatigue. Mids do sound a bit out of your head, placing them a little further out. But overall, it was a very good pair up.

In many of these IEM pair ups I preferred to use Hybrid mode.


Wired and wireless connections.

Besides being a portable DAP, you can expand 2kT functionality as a transport to drive external DAC/amp, to use external AMP, or to turn the DAP into wired/wireless usb DAC. And of course, you don’t have to be limited to wired headphones, and can take advantage of Wireless Bluetooth connection.


I tested 2kT BT Tx with various headphones; it paired up within seconds and had the acknowledgement message on the screen to indicate which codec was in use. I tested with Hiby WH2 TWS, confirmed operation within 20ft, LDAC pair up, and full remote control. Also, tested with Sennheiser HD1 M2, confirmed operation within 20ft, aptX pair up, and full remote control. 20ft operation in open space was OK, though SP2k operates up to 30ft.

2kT also has Bluetooth Sink Mode (BT Receiver) to enable BT DAC “Rx” mode and to use 2kT as a wireless DAC. Once turned on, I was able to find and pair up with 2kT from my Galaxy smartphone and set LDAC codec.

USB Audio Out.

Tested with both Lotoo S2 and L&P W2 usb DAC/amp dongles without a problem. In notification bar of 2kT have to be sure External USB is selected to enable USB Audio mode. Volume on 2kT was fixed at 150, so I was able to adjust it from S2 and W2. The sound characteristics was typical of S2 and W2 corresponding sound sig while using 2kT as a digital transport.


Recognized right away on my ThinkPad T480s (Win10Pro) laptop. In notification bar of 2kT have to tap USB Mode to select DAC. Volume can be adjusted from laptop or 2kT. No need to install any additional drivers, and the sound was typical of 2kT output. As a matter of fact, the sound is nearly the same playing locally from 2kT or from laptop using 2kT as USB DAC.

Optical Out.

Was using iFi micro iDSD for this testing, nothing needs to be selected or enabled, just connect to 3.5mm port and start playing. Optical output was detected automatically, 2kT volume was set to max 150, and I was controlling the output from micro iDSD. Btw, the same with Digital out when using with micro iDSD, using OTG usb cable, the connection was detected OK, volume set to 150 and I was able to control the volume from micro iDSD.

Line Out.

Connected to Cayin C9, I had to select Line Out from notification bar and was able to control the volume from both external amp and 2kT. In Settings of 2kT, you can adjust the volume level of LO. If you need to color your sound with an external amplifier or need to drive more demanding headphones, access to LO is very convenient.


WiFi Streaming.

With the unit I received, there are no issues playing local files in any of the Amp modes, even when I turn on wifi or BT. But when streaming and only in either Tube or Hybrid modes, I get an intermittent short burst of buzzing which sounds like an EMI interference with a Tube. I asked other users on Head-fi in SP2000T thread to share their experience, and some responded with no issues, while others experienced similar. Switching to solid state output amp is one of the solutions when streaming if you are experiencing EMI and it bothers you. You can also download and store your favorite tracks for off-line listening from some of the apps.

At the time of writing this review, I was told that A&K is trying to understand the random nature of this problem.


While writing the review, in the back of my mind I was thinking why A&K decided to keep SP2000 base model number in this new original design. And I kept coming back to the thought of SP2000T still being at the top of their SP flagship series, sharing the crown with SP2000 SS and Cu daps. Perhaps, A&K didn’t exactly reinvent the wheel with either a modular dac/amp design (SE180) or a dual solid state and NuTube output amp design (SP2000T), but they certainly managed to take both to the next level and in case of 2kT introduce a new hybrid twist while mixing both amp modes.

The implementation of dual amp design with a triple output mode is not a gimmick. When you listen closely, you can hear the difference in bass performance and mids tonality, giving you a choice between the original (SP2000) solid state amp tonality and the NuTube tonality. But despite the mode of the internal amplifier, we are still dealing with a solid build, quad ESS Sabre flagship DACs, natural detailed tonality, very polished user interface, semi-Parametric EQ, SE and BAL headphone output jacks, and capability to play not only local files but also to stream popular services.

Is SP2000T going to dethrone SP2000? I don’t think so because one is not the upgrade of the other, and instead, they both coexist in a complementary way. Actually, in the last two weeks of my SP2000T testing I end up reaching more for “T” instead of SP2000 SS because variation of amp modes was more fun when pairing up of IEMs with different sound sigs. I’m sure the next gen flagship is coming in a near future, but in a meantime, you don’t have to wait and can start enjoying a new current gen flagship from A&K.
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Excellent review! Thanks.

Dobrescu George

Reviewer: AudiophileHeaven
Astell&Kern A&Ultima SP2000T - Tube & Solid State Blends Musically
Pros: + Sonic Quality is Ultimate, just like the name
+ Great Os Experience
+ Support for Tidal, MQA, MQS, Stremaing
+ LDAC and Bluetooth Sink (Bluetooth DAC Support)
+ Construction Quality
+ Tube AMP inside a DAP, with awesome life expectancy
+ Edgy design that's still comfortable and portable
+ 4.4mm Balanced Output, 3.5mm SE Output, 2.5mm BAL output
+ Vibrant, colorful display
+ Fluid, snappy OS
+ USB DAC functions, it works flawless as a USB DAC
+ Navigation buttons
Cons: - Pricey
Astell&Kern A&Ultima SP2000T - Tube & Solid State Blends Musically


The best part about reviewing a 2500 USD Music Player with Hybrid Tube - Solid State tech inside is that you can compare it to pretty much everything else, and you still know it is going to be a fun trip. Today's review will focus on a true prime flagship, the SP2000T DAP, which features multiple bleeding edge technologies, including LDAC, Quad-DAC, a Triple AMP System, MQA support, BT Link, and Dual Wifi with both 2.4GHz, and 5GHz support. The price alone puts in as the most promising Music Player to date, so it needs to be compared to the absolute best DAPs in the entire world, including Lotoo PAW 6000 (1200 USD), iBasso DX300 (1200 USD), iBasso DX220 MAX (1880 USD), Astell & Kern SE180 (1500 USD), Cyrus One Cast (2000 USD), and Mytek Brooklyn DAC+ (2000 USD). Since we're talking about the Crème de la Crème here, we'll be pairing the SP2000T with the best earphones and headphones out there too, including Campfire Ara (1300 USD), Crosszone CZ-10 (900 USD), Sendy Audio Peacock (1500 USD), Unique Melody MEST MK2 (1500 USD), and Audeze Euclid Planar IEMs (1300 USD).


While this isn't the first time I'm reviewing an Astell & Kern DAP, they never cease to amaze with both the package, and the overall construction, as well as the physical qualities of their products. The company offers one of the best warranty out there. What's more interesting is that they will have support for their modular DAPs that extends well, and their DAPs are some of the most longeval ones out there. Astell & Kern are generally regarded as a company that's slightly more pricey than the vast majority of DAP makers, offering a premium package. It looks like with today's market, they aren't more expensive than the competition, but they still offer that premium package, premium build quality, and premium software that is intuitive and bug-free. It is worth to mention that you can rely on Astell & Kern to offer proper warranty for their products, even if you're close to the end of the warranty, and it is worth to mention that they are bleeding-edge technology developers, and won't stop at anything from delivering the ultimate audio experience to you.

It should be noted that I have absolutely no affiliation with Astell & Kern. I'd like to thank Astell & Kern for providing the sample for this review. This review reflects my personal experience with the Astell&Kern A&Ultima SP2000T. Every opinion expressed is mine and I stand by it. The purpose of this review is to help those interested in A & Ultima SP2000T find their next music companion.

Package & Unboxing

While I liked the unboxing experience for the SE180, I am absolutely in love with the way Astell & Kern presents their SP2000T, as this one comes with a wooden box, to truly reflect on the kind of quality and lavish experience you can expect from the company. It also comes with a carrying case from the factory now, which is brown in color, and made of leather.



Inside the package you can also find a high quality USB cable that you can use for both charging the SP2000T, and for using it as a USB DAC. There's also a set of screen protectors for SP2000T, as well as a warranty card and the quick introduction manual, all written on black paper, further securing that high-end feeling you get when you use an Astell & Kern DAP.

Build Quality/Aesthetics/Functionality

SP2000T is a tank of a DAP, just like SE180 is, and both are really nice to look at. Impressive design, paired with great engineering, and excellent quality for the materials used in the making lead to a nice experience with the SP2000T DAP. The top part of SP2000T's back is made of glass, allowing for a good Wifi and Bluetooth signal strength, while the rest of the DAP is made of a matte finish metal. We have three navigation buttons on the left side, with a forward, play/pause and a backward button, on the left edge. The entire DAP has an angular design, but strangely enough, it is designed in such a way that it ends up being more ergonomic than most competitors, even those more expensive than it, like Sony 1Z.


On the right edge of SP2000T we have the volume wheel, and we have the power button, as well as all the audio outputs at the top, just like on SE180. Astell & Kern always futureproofs their products, so we have a 3.5mm Line Out / Headphone Output, and we have balanced outputs, in both 2.5mm and 4.4mm, and you can use both of those as true line outs. With a handy 4.4mm to XLR converter, you could practically turn SP2000T to become the main DAC in a full fledged hifi system. In fact, the company hints at this with the T termination, as they call SP2000T True, inheriting on SP2000's sound philosophy, but also T from the Triple AMP system, Tube from the Vacuum Tube AMP, and Timeless because this DAP is considered a timeless masterpiece by the engineers who made it.


Speaking of the Triple AMP System, Astell & Kern did not hold back when designing the SP2000T, and we are able to use three AMP modules with a full OP-AMP module, a full Tube AMP mode, and an in-between mode, where we can tilt how much of each amp is used, practically delivering multiple possible signatures in a single DAP. You can further expand on that with EQ, as Astell & Kern supports a very granular and detailed EQ model, with the mention that the process of setting up its EQ can be slightly time consuming. The Tube AMP is available on all its outputs, and all data rates SP2000T is able to play, no restrictions.

The Tube AMP inside SP2000T is a Dual-Triode KORG Nutube, similar to the solution that iBasso employed in their AMP12 series of modules. The company quotes the expected life time of the tube at 30.000 hours, or 1250 days of continuous usage, or about three and half years of continuous usage. Since no one physically can listen for that long to a single source, you can expect the realistic life of the Tube in SP2000T to be between eight, and twelve years, or longer, so there's no need to worry about burning through its life. The design is actually fantastic for someone who finished engineering school, having an anode grid filament that operates the same as a triode vacuum tube. This comes with the advantages of a much lower power consumption, much less heat generated, and better overall life for the tube. The name of the Nutube is KORG Nutube 6P1.


Speaking of the temperature, while in usage SP2000T gets moderately warm, but it is nowhere near how hot FiiO M15 gets, or M17, which FiiO sells with a fan because they couldn't cool it off enough. This goes to show the difference in engineering experience, where Astell & Kern is able to create a DAP that can effectively implement a Top Of The Line DAC, NuTube AMP, without burning through your pocket, but FiiO needs to ventilate their latest DAP with a fan, creating noise, the biggest enemy of us music lovers.

Speaking of noise, Astell & Kern implements their Teraton Alpha system which is basically a name for all the efforts Astell & Kern makes toward isolating all the noise that could appear in a portable music player. Since we're talking about a Tube AMP, and Tubes can be microphonic, and the slightest movement can introduce noise, Astell & Kern effectively redefined the way the internal structure of SP2000T works, and both sides of the tubes are fixed with flexible silicone covers, while the tube is separated from the main PCB, being a module. This also hints at the possibility to replace the tube module down the line, if need ever be. The most surprising addition for SP2000T is the magnetic polarity flat mechanism, which basically means that the AMP floats in the air, being held by strong magnets, minimizing noise that could come from the tube itself, kind of like floating turntables work. Still on the noise isolation, Astell & Kern applied a silver plated shield to SP2000T, and the entire audio block of the music player is fully isolated from electromagnetic interference.


We have the same solutions as we've seen on SE180 implemented too, for power noise removal, power management and most importantly, this works. I can use SP2000T as a USB DAC with absolutely no change in the sonics compared to using it as a portable music player.

The display found on SP2000T is a 5.0" , FHD 1920*1080, 441 PPI high density display with good color reproduction. The DAC part is supported by a Quad-DAC design, with four ES9068AS DACs running in parallel to provide you with the best sonic performance possible. There is support for true gapless playback, as well as replaygain, and SP2000T has Dual - Band Wifi support, having support for both 2.4GHz and 5.0GHz Wifi signals. As you would expect, downloading a song from Tidal is almost instantaneous, and everything works buttery smooth.


The battery life of SP2000T is really solid, and it can push up to 9 hours of rated music playback on a single charge, which I found to be close to actual experience, as I've been able to push it for about 8 hours of continuous playback at high volumes, tons of Screen On Time or SoT, and with usage of both the Tube and the OP AMP modes interchangeably. The first few cycles were lower compared to the battery life after the 5th cycle. SP2000T has fast charging, which is really awesome, but even with fast charging, it takes about 3 hours to fully charge it from about 5%, which is quite high. Without fast charge, it can take up to 5 hours to fully charge it, but realistically speaking, the chances of you having a normal speed charger for their phone and being interested in investing in a high-end DAP like SP2000T are low.


We have excellent numbers for the audio output of SP2000T as well, with the SNR being rated at 121 dB Single Ended and 123dB for the Balanced connector. We also have a Crosstalk of -137dB for the Single Ended output, and -142 dB for the Balanced connector. The THD is 0.0003% for the Single ended connection, the same as the one for the balanced connector. The output impedance, the most important aspect from the measured technical performance, is 1 Ohm for the Single ended output, and 1.5 OHMs for the Balanced output, very good numbers, allowing SP2000T to drive sensitive IEMs like Campfire Atlas, Unique Melody MEST MK2, and Final Audio A8000 with minimal to zero background noise, as I noticed in my tests. We have a full voltage of 3.0Vrms on the Single ended connector, and 6.0Vrms on the Balanced connector.


The biggest surprise for SP2000T is that they don't make excuses at all when it comes to a high-end DAP like SP2000T,and they include 256 GB of internal memory, and a microSD slot that supports up to 2TB of external memory. This is the best DAP I can recommend for streaming, as tidal likes to make libraries on the internal memory, plus Astell & Kern has full MQA support. In fact, there's very little focus on the CPU that has been used inside of SP2000T, as the entire environment has been written to be perfectly bug-free and stable, plus to smooth out the user experience with SP2000T. We do know that SP2000T uses a Quad Core CPU. Future firmware upgrades are supported via OTA, and Astell & Kern is one of those companies that will offer excellent support for their DAPs.


One interesting feature of SP2000T is the Bluetooth sink, which basically means that you can use SP2000T as a Bluetooth DAC. It wouldn't be interesting if this weren't Astell & Kern, because they made every effort to make it sound good, so we have LDAC, aptX HD, and Bluetooth Sender support. This means that you can use it as both a Bluetooth source, and as a USB DAC. If you're used to the A&K Ecosystem, you have AK File drop to transfer music files wirelessly from your computer to your SP2000T, so you don't have to worry about using USB Cables, slow loading times, or messing with syncing music libraries. In my personal experience, SP2000T does something in the background, because I'm hearing a minimal loss from using it as a Bluetooth DAC, and it sounds almost as good as playing files from its internal or external memory, and almost as good as using it as a USB DAC. If there's one word to describe this, it is coherency, SP2000T remains coherent, regardless of the usage scenario you want it for, having the same, stable signature.


One little detail that I appreciate is that the glass back has a little LED mode that lights up as RED for normal OP-AMP mode, Orange for Tube Mode, and Cyan for Hybrid Mode. It can also light in different colors for confirming the bit depth of your music, red for redbook, green for 24-Bit files, and orange for 32Bit files. DSD files will give SP2000T a purple glow on that status bar at the back. You can expect full support for Hi-Res, DSD, DXD, and all of the fancy formats you can think of with SP2000T. This includes WAV, FLAC, Mp3, WMA, OGG, APE files, including CD files, ALAC, AAC, AIFF, DFF, DSF, and MQA files. The maximum bit depth allowed is 8kHz all the way to 384kHz, with 8-32 Bits per sample, and a DSD Native decoding up to DSD512, and DSD64, DSD128, DSD256, and DSD 512.


While experimenting with SP2000T and multiple USB Type-C Cables, I noticed that it sounds exactly the same regardless of what cables were used, so the Type-C USB port is fully isolated and won't introduce any noise regardless of what you're using to power it. I also noticed that the connection is stable with the default cable always, but with some dodgy cables I have around the home, it would disconnect if I'm using USB ports other than USB 2.0 ports, anything higher causing some disconnects, which I can attribute to the low quality USB Cables I have, which work just fine over USB 2.0 ports. The rule here is to have a high quality cable, like the default one, and if you're having trouble, try using USB 2.0 ports, which seem to work regardless of the cables.

Sound Quality

We need to start by clarifying the fact that SP2000T has multiple sonic modes. This is not something you can ignore, since the whole selling point is that it can work both with a Tube AMP (nuTube), and a traditional OP-AMP, but also with a hybrid combination of both. Matching the OP-AMP / Tube with the proper filter can result in multiple signatures, which although come close to each other, are different enough for me to describe them. For today's review, I have been using a multitude of headphones, IEMs, and other equipment, with the most notable ones being HIFIMAN Ananda, Crosszone CZ-8A, Crosszone CZ-10, Sendy Audio Peacock, IMR Audio Opus Mia, Earsonics Corsa, and Audeze LCD-XC. I also have been switching back and forth with other Music Players, especially Astell & Kern SE180, iBasso DX240, iBasso DX300, Lotoo PAW 6000, and FiiO M11 PRO. SP2000T is undeniably special, and the company took out all the stops when designing it, and when tuning it, taking full advantage of all the tech inside SP2000T. As suggested by a friend, I tweaked and played with SP2000T until I found that the best combinations are as follows: OP-AMP with Min Phase Filter, Hybrid 50%Tube-50%OP-AMP with Hybrid Filter, and Tube Mode with Fast Roll-Off Filter.


Astell & Kern SP2000T can generally be described as incredibly natural, with a full, deep and heavy bass, a clean, engaging and vivid midrange, and with a clean and airy treble. All my impressions were taken throughout an entire week, daily with adjustments and edits, using multiple IEMs and Headphones. Given the high price of SP2000T, and the complex nature of its output, I wanted to make sure I describe it perfectly with as little bias as possible.

Since we'll be exploring three different signatures, I will be describing each, after which I will talk about the things they have in common. Since the OP-AMP signature should be the default one, I will be exploring it first, filtered through the Minimum Phase Filter. The overall signature is the clearest here, but the most analytical, with the best resolution that SP2000T has to offer, with the least texture and overdrive. The overall sound is clean, incredibly deep, and switching back and forth between filters, feels like the Minimum Phase offers more body to the sound here, effectively balancing it to have the Astell & Kern SP2000T sound. The bass has a full depth, with a beautiful impact with every headphone, and an extremely clean overall presentation. The midrange is really engaging and free of any overdrive, overtexture or overdrive. The midrange is the cleanest, having the most analytical and clean edge with the OP-AMP sound. You can also notice a lot of body to each instrument, something which compliments both acoustic-classical music, but EDM and electro-pop too. The treble with the OP-AMP mode engaged is clean and airy, with an outrageous extension in the upper treble. Especially with rock and metal music, it is extremely easy to notice those different cymbal hits, as SP2000T is incredibly dynamic and clean, and presents everything with outstanding nuance, and micro-detail.

Next off, the full Tube mode is the purest analogue mode for SP2000T, a situation in which the sound is sweet and saturated with tasteful rich overtones, and the same excellent extension both in the treble and the bass, but with a much better texture to everything. Turning the NuTube on reminds me that we can have a pure analogue sound in portables, and listening to SP2000T in this mode feels like discovering the guitar the first time, playing my first few notes on a Guitar Tube AMP, the midrange is much more engaging and juicy, and the soundstage turns more holographic, with more separation between instruments, and a really sweet overtone to everything. Both male and female voices are really natural, but they also have a sweet tonality to them, while guitars in particular sound as they would in a real life situation. Most DAPs, especially entry-level ones, like FiiO M11 PRO sound digital and glary in comparison, whereas SP2000T with Tube Mode on sounds simply realistic. Transparency is actually better with the NuTube turned on, and it feels like it has better resolving abilities in raw detail, but it tends to have a slower decay speed than the OP-AMP. This creates the feeling of more body, a larger bass, a wider and a deeper soundstage, and a more natural sound, but slows down the overall speed of the sound. It is still plenty fast, and the attack - release time is quick enough for SP2000T to be able to face technical death metal bands with no strain.


The Hybrid mode seems to draw the advantages of both the tube and OP-AMP modes, and you can tune how much of the "Tube" and "OP-AMP" is used in the hybrid mode. For testing this mode, I left the slider in the middle, and set the filter to hybrid. I most probably have been using SP2000T mostly in Hybrid and Tube mode, as I fell in love with the natural tonality, engaging presentation and sweet overtones it has in those two modes. The Hybrid mode switches the focus on the sub-bass rather than thickness and and general body of the sound, and also switches the hi-end focus on a sound that's as quick and airy. The overall refinement is improved compared to the Tube mode, and the Hybrid mode seems to draw both the body and warmth presented in the tube mode, as well as the technical prowess we can see in the solid state mode. SP2000T is able to play the forward aggressive guitars and drums for bands like Painted In Exile, all while playing the slow and nuanced keys on the background, and keep both of those well defined, creating the odd avant garde sensation that the band is trying to convey in their songs, like the masterpiece Alucard.

Describing the overall sound of SP2000T, especially in relation to most other sources, the bass can be called deep, and earth shattering with SP2000T. Especially with special headphones that really need the extra push on the bottom end like Crosszone CZ-8A, and Sendy Audio Peacock, I can notice that SP2000T is able to deliver more impact and depth than most of the competition. The bottom end is natural in speed, and generally has a slightly long note decay, which favors both rock, metal but also Jazz and classical music. If you're a speed addict and listen to a lot of aggressive metal, including stuff like Infant Annihilator, Brain Drill or Attila, SP2000T can totally keep up with them as well, but will present each drum hit with the proper body and substance it has during a live performance. With Deep House, or Trap, you will be astounded by the endless waves of bass and fine nuance that SP2000T is able to render. The whole presentation is holographic, both deep and wide, and you can start to notice this right away from the bass, which tends to have a filling effect for all music. Bass guitars have the exact amount of gain and body they have when being played live, and they sound sweet, full, slightly thick and playful.

The midrange is clean, revealing and exceedingly musical. I started to listen to some good old fashioned Rings Of Saturn, a band that combines coarse voices, with musical riffs and incredibly complex solos, to test the revealing abilities of SP2000T. It is able to easily reveal rich layers of guitars, all played at the same time, multiple voice lines sung at the same time, all while an aggressive drum pattern happens all across the sonic scape, and while sweet synth notes are being played on a slow tempo throughout the song. The revealing ability and micro-detail presentation of SP2000T is incredible, and the nuance is incredible as well. I usually have a hard time listening to Rings Of Saturn if the source can't really separate the different guitars well enough, or if it can't resolve the cymbal crashes well enough, but SP2000T proves to be a master of instrument separation and clarity. We can't keep the fun only for rock and metal, and with singers like Jill Tracy, SP2000T reveals a really natural tonality for voices, but also a good amount of body and substance. This is something I mention a lot throughout the review of SP2000T, but it really has a good amount of body without being too thick or dark, just some nice smooth body and good substance to music. Most listeners and Astell & Kern enthusiasts go for those DAPs thanks to the sweet bass, and excellent midrange. I would call SP2000T the most musical DAP I heard to date, it is really musical, vivid and clean. I would be willing to say that it does a big favor to wellr recorded music, by presenting it with all the detail and color it should have like Die Antwoord - Enter The Ninja, but poorly recorded music sounds excellent as well, and with SP2000T, I am finding myself having a blast listening to some rap like Stromae - Humain A L'Eau, or Hollywood Undead - Everywhere I go, where around 1:21, SP2000T reveals a really nice effect in the left ear that I haven't really noticed with any other source before.


Music is nothing without some controversy, so I switched to a band that uses extreme synth patterns, along with what is often called one of the weirdest voices of all times - Mindless Self Indulgence. SP2000T shows excellent ability for playing cymbals, but they are always on the smoother end when it comes to textures, so SP2000T is never fatiguing. This being said, it has lots of energy and presence in the treble, doesn't sound rolled off, and the treble isn't pushed behind other instruments, if it wasn't intended in the recording for it to be as such. With songs like System Of A Down - Forest, the cymbals are always there, played right next to the guitars and the voice, as their album Toxicity is recorded and mastered to be loud and forward. I love how SP2000T can play one of the most aggressive songs of all time, but with such a slightly smooth texture to the cymbals, so that they are impactful, vivid and bitey, but not harsh, metallic or fatiguing. Even on songs like System Of A Down - NuGuns, the solo at 1:31, the acoustic guitar is presented with all the bite and sparkle it should have live, while background guitars continue playing different tunes in each ear, and the drums are presented frantically with a ton of energy, as was intended by the band.

Regardless of the Tube Mode used, SP2000T is always incredibly dynamic, and can present songs that are mastered with extremely little dynamic range as engaging, colorful, vivid and detailed. Most sources do just fine with extremely well recorded music, and start distorting and causing odd artifacts with extremely compressed music like Andrew W K - Ready To Die, while SP2000T is literally capable of presenting every instrument well defined, from the quietest to the loudest volume, even with almost no dynamic range in the mix. There's zero distortion regardless of volume, and what I found best about SP2000T is that it has absolutely the same performance for all volumes. With most DAPs, as well as headphones, you get results that it sounds better either at loud or quiet or medium volumes. SP2000T is not like that, it is made to sound perfect at all volumes. Given the price, it is not surprising, but this should be written as an engineering feature, because it is rare for a DAP to have the headroom and sonics designed so well that it won't force you to enjoy music at a certain volume, but it will let you select that volume.


Since SP2000T is priced at the high-end level, it needs to be compared to all the best DAPs that I reviewed over the years. This includes iBasso DX300 and DX220 MAX, Lotto PAW6000, Astell & Kern SE180, Cyrus One Cast and Mytek Brooklyn DAC+. We are looking at a portable music player that has the ability to replace your entire music system, DAC + Headphone AMP, and which can drive needy headphones, which is why I included two full desktop pieces of equipment. I wish I could have included a desktop DAP from FiiO like their M15 and M17, but unfortunately they decided to lower the availability and increase the price of their DAPs, and M17 in particular has a noise source inside, the cooling fan, which stands against the whole idea of SP2000T's design to be noise-free. As long as you appreciate a noise-free experience from your music, SP2000T will provide a more fun trip for you, along with better sonics than either M15 or M17.


Astell & Kern A&Ultima SP2000T vs Lotoo Paw 6000 (2500 USD vs 1200 USD) - There are huge differences in the design and performance of PAW6K and SP2000T, but also in the price of the two. The overall depth and speed is better on SP2000T, 6K being a softer sounding DAP with more emphasis on fine nuance and a splashy presentation. There's more dynamic in SP2000T's sound, with more impact and slam, but PAW6K can sound a bit more soft and refined at times. If you're looking for a lot of body in your music, along with a strong emphasis on impact, an organic texture, and an airy treble, then SP2000T should be your guy. The actual raw detail level is rather close between them, and while SP2000T holds the edge for sure, PAW6K's softness helps if your headphones / IEMs sound edgy already. SP2000T sounds beautiful with absolutely everything it is paired with, and has more Streaming features, Wifi, Tidal, and such, while PAW6K has an easier to use, albeit slightly less powerful EQ implementation. Driving power is higher on SP2000T, as it can handle very hard to drive headphones like HIFIMAN ARya Stealth better, and it has a lower noise floor as well, handling very sensitive IEMs with no background noise or hissing.

Astell & Kern A&Ultima SP2000T vs Cyrus One Cast (2500 USD vs 2000 USD) - If you are reading this comparison, you may already be lamenting about why am I even doing it, well, it is because I was asked to by many readers. The overall device, as I have them side by side, is much smaller on SP2000T. The DAC performance, and AMP performance is better on SP2000T, for driving headphones. It has more body, more depth, more slam, and better control with the sub-bass and the bass. This being said, while both can be excellent DACs and Headphone AMPs, One Cast has a high efficiency, Class D Power Amplifier for speakers inside, and for the price you're paying for it, you get one of the cleanest, most controlled speaker AMPs you could get around the price, plus it has a Phono PRE as well. I personally find them equally enjoyable for headphones, because Cyrus One Cast is convenient as my main AMP in my desktop setup, but if I was paying attention to the sonics only, or using IEMs, SP2000T wins hands-down. Cyrus One Cast is not weak in any way, and I find it a beautiful media center, it just happens that when you refine a portable music player, as Astell & Kern did, you end up with a product like SP2000T, a DAP that can beat most desktop equipment out there, even that priced at the same point as SP2000T.

Astell & Kern A&Ultima SP2000T vs iBasso DX220 MAX (2500 USD vs 1880 USD) - The biggest difference here is evident, and although the pricing is rather close, DX220 MAX is much heavier, much thicker, much bigger and less portable than SP2000T, needing a special power converter for charging, and not ideally portable as a DAP. The overall interface is smoother and quicker on SP2000T, and it offers better support for streaming and other bells and whistles, like acting as an LDAC Bluetooth receiver. DX220MAX is a big time honeymoon wow factor DAP, which means that it impresses a lot at first, but once you figure out that it is not entirely practical, you use it mostly at home. SP2000T, on the other hand, will keep impressing you with every chance it has, and never gives you up, never lets you down. SP2000T is practical for everyday use, and it is currently in top 3 my most used DAPs, as well as the most practical DAPs that I know of. In terms of sonics, DX220 MAX actually sounds a bit softer than SP2000T, and SP2000T ends up sounding more textured, more punchy in the sub-bass, with more slam and impact, DX220 MAX is softer and has a bit more thickness in the midrange, where SP2000T sounds more natural. DX220 MAX has a smoother treble, where SP2000T has more sparkle and air in the treble. SP2000T sounds more lively and natural, more vivid, wider, while DX220 MAX sounds a bit deeper and more forward in the voices. Detail resolving abilities are better on SP2000T.

Astell & Kern A&Ultima SP2000T vs Astell & Kern A&Futura SE180 (2500 USD vs 1500 USD) - I feel tricky about saving this for almost last, because this is the most complicated comparison, but the comparison I have spent the most thinking about while writing about SP2000T. The overall detail and clarity is similar between the two, but SP2000T tends to have more bottom end, more slam and more bass. It also tends to have a slightly more sparkly treble, and a more colorful, more vivid midrange than SE180. For this comparison I have been using the SEM 2 Module for SE180, and during all tests, SP2000T has more warmth and a more pleasing tonality to the midrange than SE180. SE180 ends up being slightly more analytical though, and although SP2000T has more personality, SE180 is not that far behind, and at times it presents music with similar width and depth. As for DAPs, I prefer SP2000T because it has 3 navigation buttons, against the one navigation button on SE180, and it comes with a case from the factory, which is a huge plus since third party cases for SE180 are rare. Both have excellent background noise control, and both have virtually no hiss with sensitive IEMS. Although SP2000T is more pleasing tonally, especially with the Tube Mode On, until the Tube warms up, it tends to have a less impressive sound, so you need to do a warm-up ritual with it, while SE180 is good to go as soon as it turns on, making it slightly more convenient. At the end of the day, for pure music quality alone, SP2000T is indeed a bit better, but if you're looking for an excellent all-rounder DAP, SE180 is no slouch and I actually end up using it as much as SP2000T, both being in the top 5 DAPs I heard to this date.

Astell & Kern A&Ultima SP2000T vs Mytek Brooklyn DAC+ (2500 USD vs 2000 USD) - We have a really hard quest on our hands here, because I actually end up preferring the sound of SP2000T over the Brooklyn DAC+ every single time, and in every single scenario. It sounds better driving single ended headphones, it sounds better driving balanced headphones, and even used as a DAC, it has a better overall sonic presentation, which is more natural, more detailed, and has less background noise. While Mytek's creation is no slouch, the technological advancements and refinement that Astell & Kern brings to the table is huge. They are able to beat a high-end DAC / AMP at their own game, with a portable music player. Even using SP2000T as a USB DAC, it still has less background noise, better clarity, detail, and a more holographic soundstage, with better overall bass depth and treble extension that Mytek Brooklyn DAC+, revealing just how far we've come in the last few years with those portables.


Since SP2000T is a high-end music player, I brought pairings again, and this time even more than I added to me SE180 review, so this time we have pairings with both hard to drive IEMs, as well as headphones, including Unique Melody MESt Mk2, Audeze Euclid, Sivga Peacock, Campfire Ara, and Crosszone CZ-10. If you're curious for more pairings or more comparisons, don't be shy and leave a comment, I'm always around, and with an arsenal of over 400 product reviews to date, I may be able to help.


Astell & Kern A & Ultima SP 2000 T + Campfire Audio Ara (2500 USD + 1300 USD) - Where some listeners found the Ara to be a bit too linear and neutral for their tastes, SP2000T actually gives them a really punchy and deep bass, with great slam and a ton of dynamics. For an IEM, Ara sounds like an open-back headphone, or a set of high-end Vector Speakers, it is simply colorful, punchy and natural. I love the overall soundstage too, and while Campfire Audio is generally known for their soundstage, SP2000T generally has this wide / holographic presentation that it infuses to anything it drives, giving Ara a really engaging and fun presentation, to the point where I would consider this to be an end-game setup for this year, and posting this review so close to the end of 2021, if I had to award any pairing a "pair of the year" award, SP2000T + Campfire Ara would be in top 3 contestants.

Astell & Kern A & Ultima SP 2000 T + Crosszone CZ-10 (2500 USD + 900 USD) - I know I commented on this in the SE180 review, but Crosszone Headphones transform into something else entirely when powered by Astell & KERN DAPs, SP2000T being no exception. The overall bass and depth is something else entirely, and SP2000T, really enriches the midrange of CZ-10. I just received the Crosszone CZ-8A and I have been noticing the same effect, where the bass and midrange are something really different with A&K DAPs, and those Crosszone headphones reach a point where I consider them proper end-game headphones. Not only that, but with a soundstage like HD800S, yet warmth and bass slam like LCD-2C, CZ-10 is a real wonder to listen to.

Astell & Kern A & Ultima SP 2000 T + Unique Melody MEST MK2 (2500 USD + 1500 USD) - Mest MK2 is one of those IEMS that really sound beautiful but do not need a lot of power or a specific source. I added it to this list because the pairing has one of the most vivid and detailed midranges I've heard in ages, plus a really full and clean bass. MEST usually has a pumpy, but not very full bass, with SP2000T, the bass becomes fuller, deeper and better controlled. SP2000T also has an effect on making the midrange of MEST 2 really colorful and empowered with micro detail.

Astell & Kern A & Ultima SP 2000 T + Sendy Audio Peacock (2500 USD + 1500 USD) - I was surprised that my video review of the Peacock was not received as well as the full written review, especially as I have been using them more and more, and I feel like they're under appreciated for their sound. It is very possible that those who didn't like the Peacock never tried them with a proper source, so I'm willing to say that SP2000T is able to power them the best out of all the DAPs I heard to date, giving them the most natural midrange, deepest bass, and most sparkly, yet controlled treble. There's a natural sense of dynamics, and the detail is incredibly good too, creating a signature that can never be boring for the Peacock.

Astell & Kern A & Ultima SP 2000 T + Audeze Euclid Planar IEMs (2500 USD + 1300 USD) - Euclid displays one of the largest improvement when paired with SP2000T compared to other DAPs thanks to the organic, smooth and natural midrange that only SP2000T has. There's more than enough power for the Euclid, but the dynamics are excellent, the detailing is also superb, so there's nothing that SP2000T can't do with the Euclid. For those who aren't satisfied with the sound, even after SP2000T does its magic for the midrange and the bass, then you can engage some user friendly EQ on SP2000T, and you'll hear a delicious amount of bass, as it has a higher headroom than most competition, so you can feel free to pump the bass (lowering the master), until you get Euclid to sound exactly as you want.

Value and Conclusion

If you reach that point where you want just the best thing you can get, and a bug-free experience, you know you're willing to pay whatever it takes to get it. I'm personally fed up with having to deal with buggy software, but not necessarily from audio, but smartphones and other desktop hardware I've been using. There is a single fan in my desktop computer that buzzes, and when that happens, it distracts me from music, and gets on my nerves. The downside is that I would have to replace 12 fans one by one to check out which is the problematic one, and it breaks my heart knowing I have to do that instead of sharing those awesome reviews with you. Back to the value of SP2000T, its price is high, at 2500 USD, but the value is good, because the company actually delivers what it promises and keeps SP2000T above the competition, they keep it as good as promised.


The package is fit for a flagship music player, and so is the overall presentation, the software, the build quality, and the support we receive from Astell & Kern. The sound is something else entirely, building upon and improving the sound that even SE180 managed to deliver, and placing SP2000T above all competition I heard to date, that tube magic being something else entirely. I feel compelled to add SP2000T to Audiophile-Heaven's Hall Of Fame as the best DAP of 2021, and crown it a king, both a marvel of engineering and sonic design. I can't wait to hear what other products Astell & Kern has in store, and how the market will be changed by it, as other companies will have to keep up and deliver something to compete with SP2000T.


At the end of today's full written review, if you're looking for a music player that has support for any function you may desire, a music player that is stable, and which will be able to serve you for almost a decade, providing sweet music, MQA support, DSD support, and a beautiful, natural, organic sound, then Astell & Kern A&Ultima SP2000T is the obvious choice to go for right now.
It is a work of art! Amazing!
Dobrescu George
Dobrescu George
Did you ever get the chance to test them with the LCD-5 or have an estimation of how they would perform with it? Thanks!


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