Astell&Kern A&ultima SP4000 Digital Audio Player
Usage Guide
DAP
Connection Guide
3.5mm Single
2.5mm Single
4.4mm Single
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Item code: AKP
Inc. VAT (20%) · Ex. VAT: £3,165.83 Ex. VAT · Inc. VAT (20%):
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If you've seen a better offer for this product, we will endeavour to match it. The competing offer must be on brand-new boxed items, and in stock from another UK Online Authorised Retailer (excluding marketplaces). Price match quotations are valid for 7 days.
SPEAKER CABLES:
A quantity of 2 means you will receive a pair of speaker cables e.g. for your front left and front right speakers. By entering a quantity of 1, you will get a cable for a single speaker e.g. centre speaker and this option also enables you to vary the length (and termination) of your cable for each speaker.
OTHER CABLES:
A quantity of 1 means you will receive a single cable in the case of aerial, satellite, subwoofer, digital coaxial & optical cables and a pair of cables in the case of 2 rca to 2 rca analogue audio cables.
NON-CABLE PRODUCTS:
A quantity of 1 means you will receive 1 of the specified products.
Order before 4pm (Mon–Fri) for same-day dispatch
Astell&Kern A&ultima SP4000 Digital Audio Player
Building on the legacy of the SP3000, this next-generation player introduces an advanced Octa audio circuit architecture with a 1:1 digital-to-analog structure. Each AK4191 digital processor pairs directly with an AK4499EX DAC, delivering exceptional signal precision and improved separation. The SP4000 achieves a true Quad DAC configuration, producing an extraordinary 131dB Signal-to-Noise Ratio for pure, lifelike sound. With twice the OPAMPs in parallel compared to its predecessor, it delivers richer detail, deeper bass, and a more expansive soundstage.
High Driving Mode ensures stable power delivery for any headphone, while ESA (Enhanced Signal Alignment) technology reduces group delay, resulting in crystal-clear audio with minimal distortion. A newly integrated Low Dropout Regulator, inspired by high-precision medical and 5G devices, reduces noise by up to 97% for unmatched purity. The SP4000 is designed for those who demand ultimate sonic performance, transforming every track into an immersive listening experience.
Features
- Enhanced signal processing capabilities with Octa audio circuit architecture
- Supports High Driving Mode for delivering premium sound quality
- Minimizes group delay with proprietary ESA (Enhanced Signal Alignment) technology
- Ultra Low Noise LDO Regulator for top-tier noise suppression
- Precision sound achieved with Any Layer Type PCB
- Equipped with a 99.9% Pure Copper Shield Can
- First Astell&Kern Device to Support Full Android OS
- First Astell&Kern Device to Feature Advanced DAR Technology
- Features 4.5th generation UI, combining functionality and emotional design
Top-Tier Noise Suppression (Ultra Low Noise LDO Regulator)
The SP4000 features a newly implemented LDO (Low Dropout) Regulator in its power supply, which reduces noise by up to 97% compared to previous models. LDO Regulators are high-performance components typically used in precision medical devices and 5G communication equipment. They help stabilize battery voltage and effectively suppress noise, resulting in cleaner, purer sound.
Precision Sound with Any Layer HDI PCB
To achieve the highest sound quality, the SP4000 incorporates top-tier Any Layer HDI (High-Density Interconnect) PCB technology. Commonly used in smartphones and high-performance electronic devices, this advanced circuit board allows for the precise design of complex circuitry within a compact space. It minimizes signal loss, enabling the delivery of a more refined and detailed sound.
Supports High Driving Mode for Premium Sound Performance
The SP4000 features twice as many OPAMPs arranged in parallel compared to its predecessor, delivering richer and more detailed sound. High Driving Mode provides powerful and stable output—much like a four-wheel-drive vehicle confidently navigating rough terrain. It’s designed to reproduce even the most delicate sonic details with precision, allowing you to enjoy deeper, clearer, and more immersive music.
Specifications
- Model SP4000 (PPF51)
- Body Color Black, Silver
- Body Material Stainless Steel 904L
- Display 6inch 2K (2160 x 1080) touch screen
- Supported Audio Formats WAV, FLAC, WMA, MP3, OGG, APE, AAC, ALAC, AIFF, DFF, DSF
- Sample rate PCM : 8kHz ~ 768kHz (8/16/24/32bits per Sample)
- DSD Native : DSD64(1bit 2.8MHz), Stereo | DSD128(1bit 5.6MHz), Stereo
- DSD256(1bit 11.2MHz), Stereo | DSD512(1bit 22.4MHz), Stereo
- Output Level Unbalanced 4.1Vrms │ Balanced 8.2Vrms (Condition No Load)
- CPU Octa-core
- DAC AKM4191 x4 + AKM4499EX x4 (Real Quad DAC)
- Decoding Support up to 32bit / 768kHz Bit to Bit playback
- Input USB Type-C input (for charging & PC & MAC)
- Outputs Unbalanced Out (3.5mm), Optical Out(3.5mm)
- Balanced Out (4.4m, only 5-pole supported)
- Wi-Fi 802.11 a/b/g/n/ac (2.4/5GHz)
- Bluetooth V5.0 (A2DP, AVRCP, Qualcomm® aptX™ HD, LDAC, LHDC, SBC, AAC)
- Dimensions 3.34” (85mm)[W] x 5.89” (149.8mm)[H] x 0.76” (19.5mm)[D]
- Weight About 21.7oz (615g)
- Feature Enhancements Firmware upgrade supported (OTA)
- Operating Temperature 0℃ ~ + 40℃ (32℉~ 104℉)
About Astell&Kern
Astell&Kern is the ultimate digital music source that brings you Mastering Quality Sound or MQS. Astell means ‘Stars’ in Latin and Kern means ‘Center’ in German. We believe Astell&Kern is the center of music.
Today, original music performances can be captured in digital almost exactly as they were performed due to new, advanced recording technology currently available. However, these high quality recordings are mainly listened to through inferior sound formats, such as MP3 or through streaming services. With the debut of the MP3 format, music lovers sacrificed sound quality for the convenience of being able to carry their music collection wherever they went. Because the MP3 format heavily compresses files for the sake of convenience, the vocals and instruments you hear are only an inferior version of the original. The soundstage and the ambience of the original performance often disappears when listening to compressed MP3 music. After pondering these issues, Astell&Kern was our solution to poor sound quality for the sake of portability, and our way in reviving the original sound quality of music, MQS, for music artists, recording engineers, and professionals.
Astell&Kern's pursuit is to provide natural and original sound without distortion. It showcases the presence of the original recording with miniscule details you may not have noticed from other music systems, while playing back high-resolution music bit by bit, exactly as it was recorded. The ability to play back the exact recording of any live performance is what Astell&Kern is known for.
The power of true sound from Astell&Kern can now be experienced and has been part of many famous audio exhibitions around the world. Astell&Kern is now admired by music lovers from many countries, including the USA, China, Japan, UK, France, and many more around the world.
About Astell&Kern
Korean maker of portable digital audio players, with a catalogue that also covers earphones, headphones and speakers.
Astell&Kern is a Seoul-based company and part of Dreamus, formerly iRiver. Its core product is the digital audio player, a portable unit that holds your music library and drives headphones or earphones directly. The catalogue also includes earphones, headphones, speakers, cases and other accessories for your player.
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Players are grouped into named series
A&ultima is the flagship line, with the SP4000 and SP3000 among its models. A&futura includes the SE300 and A&norma includes the SR35. The PD series, which includes the PD20, and the KANN line, which includes the KANN ULTRA, are separate families. Each series sits at a different level of price and specification.
High-resolution files are supported across the range
Astell&Kern lists playback of 24-bit files at sample rates from 44.1kHz to 192kHz, and supports MQS, its Mastering Quality Sound label. If you want to play DSD or sample rates beyond that, check the specification of the model you are considering before you buy.
Earphones, speakers and cases sit alongside the players
Astell&Kern also makes earphones, headphones, speakers and accessories, including cases. It has worked with VOLK Audio on the STELLA in-ear monitors. If you are buying a player, the catalogue lets you choose the earphones and the case from the same maker.
Why we stock Astell&Kern
We had DACs but nothing portable, so we went looking. Astell&Kern do one thing and have done it longer than almost anyone, with a range that runs from a first serious player up to real money. If you have invested in in-ear monitors and are still feeding them from a phone, this is the gap they fill.
Specifications
- Model SP4000 (PPF51)
- Body Color Black, Silver
- Body Material Stainless Steel 904L
- Display 6inch 2K (2160 x 1080) touch screen
- Supported Audio Formats WAV, FLAC, WMA, MP3, OGG, APE, AAC, ALAC, AIFF, DFF, DSF
- Sample rate PCM : 8kHz ~ 768kHz (8/16/24/32bits per Sample)
- DSD Native : DSD64(1bit 2.8MHz), Stereo | DSD128(1bit 5.6MHz), Stereo
- DSD256(1bit 11.2MHz), Stereo | DSD512(1bit 22.4MHz), Stereo
- Output Level Unbalanced 4.1Vrms │ Balanced 8.2Vrms (Condition No Load)
- CPU Octa-core
- DAC AKM4191 x4 + AKM4499EX x4 (Real Quad DAC)
- Decoding Support up to 32bit / 768kHz Bit to Bit playback
- Input USB Type-C input (for charging & PC & MAC)
- Outputs Unbalanced Out (3.5mm), Optical Out(3.5mm)
- Balanced Out (4.4m, only 5-pole supported)
- Wi-Fi 802.11 a/b/g/n/ac (2.4/5GHz)
- Bluetooth V5.0 (A2DP, AVRCP, Qualcomm® aptX™ HD, LDAC, LHDC, SBC, AAC)
- Dimensions 3.34” (85mm)[W] x 5.89” (149.8mm)[H] x 0.76” (19.5mm)[D]
- Weight About 21.7oz (615g)
- Feature Enhancements Firmware upgrade supported (OTA)
- Operating Temperature 0℃ ~ + 40℃ (32℉~ 104℉)
We use Royal Mail 1st Class services for our Standard Delivery.
Orders received before 4.30 pm Monday to Friday are usually dispatched the same day by FIRST CLASS post (unless premium postal or timed courier services are selected), subject to stock availability. This does not apply to custom-length cables and speaker cables as these require a longer timescale to terminate. This also excludes all cables selected for the burn-in service. Please note, we do not process orders on national holidays in the UK. Over 98% of our orders are delivered the next working day including Saturdays.
Standard delivery is usually within 2 working days, although 98% of all orders are delivered the next working day including Saturdays. In extreme cases, such as delivery to the Highlands and Islands, this may take 3 days.
All items are fully insured and come with an invoice from Future Shop. We use the Royal Mail for delivery of small packages and DPD Local or DHL for items that weigh over 2KG. Items over 2KG are fully insured and will usually be delivered within 48 hours of placing your order subject to stock availability. For international orders, we use FedEx or DHL services where customers have selected this option.








Please note, special orders for non-standard cable lengths may be subject to longer deliver time-scales. This may vary from manufacturer to manufacturer.
We offer 'Free delivery on orders over £99' subject to the following terms & conditions:
- Applies only to orders with £99 or more of items (including VAT at the UK rate), at Future Shop
- Free Delivery on orders over £99 utilises Royal Mail First Class postal service for items weighing under 2KG. For items weighing over 2KG, we use DPD or DHL next working day services which deliver from 9.00am to 6pm within mainland UK (excludes Royal Mail Special Delivery Services and timed next day delivery services by DPD or DHL).
- Applies only to deliveries to addresses within mainland UK and Northern Ireland addresses. Applies only to orders that are to be delivered to a single Mainland UK delivery address.
- You will not be eligible for free delivery on your order if any items are cancelled or returned for a refund, bringing the total order amount below £99. Where items are returned, the refund due will be the cost of the item less any postage costs.
- We reserve the right to change or discontinue 'Free delivery on orders over £99 promotion at any time.
- FREE DELIVERY FOR ORDERS OVER £99 OFFER DOES NOT APPLY TO TRADE CUSTOMERS.
UK Postal & Delivery Charges - FIRST CLASS
Free UK delivery on all orders over £99*
| Weight | Price (FIRST CLASS UK POSTAGE) |
| 0g - 1000g | £3.95 |
| 1000g - 1400g | £4.95 |
| 1400g - 1800g | £5.95 |
| 1800g - 2000g | £6.95 |
| 2000g - 3000g | £8.95 |
* Free Delivery on orders over £99 utilises Royal Mail First Class postal service for items weighing under 2KG. For items weighing over 2KG, we use DPD or DHL next working day services which deliver from 9.00am to 6pm within mainland UK.
Free Delivery for orders over £99 excludes Royal Mail Special Delivery Services and timed next day delivery services by DPD or DHL.
Special Delivery UK - Guaranteed Next Working Day
We have 99.9% of the UK covered With Royal Mail Next Day Special Delivery. We guarantee delivery to most UK addresses by 1pm the next working day. This includes Northern Ireland, Jersey and Guernsey. Some places take longer to deliver to but we still guarantee delivery within three working days by 5.30 PM.
Please note, Royal Mail Special Delivery for next working day may not be possible where non-standard cable lengths are ordered. If this is the case, the item will be shipped via The Royal Mail Special Delivery service as soon as the cable is custom made.
For orders weighing over 2KG, we reserve the right to ship items using Next Day Pre-Noon Courier Services where Royal Mail Special Delivery option has been selected.
Channel Islands & Northern Ireland
We accept orders from all Channel Islands including Alderney, Jersey, Guernsey and Sark. Unless you select a premium service, Items weighing under 2KG are delivered using our standard UK delivery option above. For items weighing over 2KG, a surcharge may be applied for all deliveries to the Channel Islands as well as Northern Ireland.
European Countries
Deliveries to EU member states are not subject to 20% VAT after December 31st 2020 and therefore the 20% VAT on items is automatically deducted when you log-in, register or proceed to place an order.
The customer will be liable for the VAT at the local VAT rate, duty on the import and the brokerage service fee if applicable. This may need to be paid in advance to your local Customs & Excise office or the delivery company before your order can be delivered.
We offer the following shipping services:
- Royal Mail First Class International Airmail Services - Items are usually delivered within 3 to 5 working days
- Royal Mail Standard International Mail Services - Items are usually delivered within 7-10 working days
- DHL Express International - Items are usually delivered within 24 to 48 hours. DHL orders must be received by 3:30pm for next day service to most destinations in Europe
- Federal Express International Priority - Items are usually delivered within 24 to 48 hours. FedEx orders must be received by 3.00pm for next day service to most destinations in Europe
- Federal Express International Economy - Item are usually delivered within 48 to 72 hours
We reserve the right to change your shipping method without notification if you select a method that we cannot use for your shipment (for instance, we cannot ship via postal services for items over 2 Kg to International destinations). If we need to change your shipping method, we will choose the least expensive shipping method for your order.
Worldwide - Excluding UK & Europe
Deliveries outside of the UK are not subject to 20% VAT and so the 20% tax on items is automatically deducted when you log-in, register or proceed to place an order.
If applicable, the customer will be liable for the taxes at the local tax rate, duty on the import and the brokerage service fee. This may need to be paid in advance to your local Customs & Excise office or the delivery company before your order can be delivered.
We offer the following shipping services:
- Royal Mail First Class International Airmail Services - Items are usually delivered within 7 to 10 working days
- Royal Mail Standard International Mail Services - Items are usually delivered within 15 working days
- DHL Express International - Items are usually delivered within 24 to 48 hours. DHL orders must be received by 3:30pm for next day service to most destinations in Europe
- Federal Express International Priority - Items are usually delivered within 48 hours. FedEx orders must be received by 3.00pm in order to ship items the same day, subject to stock availability
- Where the actual weight of the package significantly exceeds the shipping cost charged on orders, we may write to you for an additional shipping charge. For larger orders, items may be shipped in multiple packets at our discretion
We reserve the right to change your shipping method without notification if you select a method that we cannot use for your shipment (for instance, we cannot ship via postal services for items over 2 Kg to International destinations). If we need to change your shipping method, we will choose the least expensive shipping method for your order.