The A&ultima SP4000 DAP is Astell&Kern's new flagship digital audio player, delivering a sound experience that's refined, powerful, and remarkably close to perfection. As part of the A&ultima series–Astell&Kern’s flagship lineup combining cutting-edge technology and top-tier ...The A&ultima SP4000 DAP is Astell&Kern's new flagship digital audio player, delivering a sound experience that's refined, powerful, and remarkably close to perfection. As part of the A&ultima series–Astell&Kern’s flagship lineup combining cutting-edge technology and top-tier specifications—the SP4000 surpasses the boundaries set by the A&ultima SP3000 DAP, once regarded as the ultimate audiophile reference music player.
The SP4000 DAP is the result of three years of relentless research and innovation following the development of the SP3000. Built upon an advanced Octa audio circuit architecture with true Quad DAC implementation, the SP4000 surpasses the boundaries set by the SP3000, delivering an exceptional 131dB SNR. This is the first Astell&Kern product with full Android OS integration, enabling bit-perfect lossless streaming through proprietary ADP (Astell&Kern Direct Path) technology.
The SP4000 introduces Advanced DAR (Digital Audio Remaster) with VSE technology for enhanced restoration, powered by a Snapdragon 6125 Octa-core processor with 8GB DDR4 memory. Crafted from 904L stainless steel–a first in portable audio–it features cutting-edge technologies including enhanced signal alignment for minimized group delay, Ultra Low Noise LDO Regulator providing 97% noise reduction, and a 99.9% pure copper Shield Can for superior electromagnetic shielding. Revolutionary Audio Architecture True Quad DAC with Octa Audio Circuit Technology The SP4000 portable music player marks a breakthrough in high-end portable audio engineering.
While the SP3000 used a 1:2 digital-to-analog processing ratio, the SP4000 evolves to a precision 1:1 architecture. Each AK4191 digital processor pairs with a dedicated AK4499EX DAC, delivering digital signals directly without noise distribution. Through continuous research and innovation in circuit technology, the SP4000 successfully implements a true Quad DAC—a feat previously considered impossible due to noise and other issues.
As a result, the SP4000 achieves an impressive SNR (Signal-to-Noise Ratio) of 131dB, on par with the independent dual audio circuit of its predecessor. High Driving Mode with Parallel OPAMP Configuration The SP4000 features twice as many OPAMPs arranged in parallel compared to previous models, delivering richer and more detailed sound. The amp's 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. Unlike OPAMP series configurations that increase noise while boosting power, the SP4000's parallel alignment expands the driving range horizontally with no noise increase or SNR reduction. This results in enhanced dynamic range and superior sound detail.
[OPAMP: Series Configuration] Driving range increases linearly, but with increased noise and reduced SNR. While the sound may feel more powerful, it tends to become rougher or harsher. [OPAMP: Parallel Configuration] The driving range expands horizontally, with no increase in noise or reduction in SNR.
This results in increased dynamic range and enhanced sound detail. ESA Technology: Eliminating Group Delay Astell&Kern's proprietary Enhanced Signal Alignment (ESA) technology addresses one of audio's most persistent challenges—group delay. ESA aligns frequency signals to arrive more uniformly, minimizing frequency distortion and dramatically enhancing sound clarity and purity.
Group delay occurs when different frequencies pass through a system at varying speeds, causing slight time differences that blur audio precision. ESA technology ensures all frequencies arrive simultaneously for pristine, coherent sound quality. Premium Hardware Engineering Ultra Low Noise Power Supply The SP4000 incorporates a newly implemented LDO (Low Dropout) Regulator that reduces noise by up to 97% compared to previous models.
These high-performance components, typically reserved for precision medical devices and 5G communication equipment, stabilize battery voltage and effectively suppress noise for exceptionally clean, pure sound reproduction. Advanced PCB Technology To achieve maximum sound quality, the SP4000 DAP features top-tier Any Layer HDI (High-Density Interconnect) PCB technology. [ SP3000 Layer Structure ] [ SP4000 Layer Structure ] 99.9% Pure Copper Electromagnetic Shielding For the first time in Astell&Kern's lineup, the SP4000 employs a precision-engineered Shield Can made from 99.9% pure copper.
This advanced shielding blocks electromagnetic