Astell & Kern / A&ultima SP4000 Copper

＜＜February 2026 New Product！＞＞The A&ultima SP4000 Copper is a limited edition model that uses copper, which has excellent conductivity and shielding properties, as the housing material for the latest flagship SP4000, which boasts outstanding sound performance, and is further enhanced by a special multi-layer coating for increased durability.

■ [Pure Sound Resonance] SP4000 Limited Edition Model Featuring Copper Housing
・The A&ultima SP4000 Copper is a limited edition model that adds new value to the flagship SP4000 audio player, boasting exceptional sound characteristics. The housing is made of copper, a material with excellent conductivity and shielding properties. While theoretically one of the most ideal materials for audio applications, copper is also extremely difficult to apply to actual products. Its exceptional electrical conductivity and superior electromagnetic shielding properties minimize even the slightest signal loss. However, its rapid oxidation and poor surface stability make it extremely difficult to apply in practical applications. This risk is even greater for portable devices, which are constantly exposed to temperature changes and external environments. Rather than shying away from this challenge, Astell&Kern faced it head-on, employing an advanced multi-layer coating process requiring advanced technology to ensure the long-term stability of 99.98% pure copper. The exterior design, too, is far from decorative. High-purity copper is a material prone to minute deformation during processing, but Astell&Kern's decades of expertise allow for extremely precise control. The result: the A&ultima SP4000 Copper, not a mass-produced item, is a beautifully finished high-end audio object. And above all, its sound is the culmination of this uncompromising craftsmanship. The sound, free of exaggeration and coloration, vividly captures the texture and weight of the instruments, as well as the speed and breathiness of the performance. The inherent properties of copper further refine the expression of the original sound, achieving a truly essential expression. Deep, powerful lows, dense, and clear mids, and naturally fading highs flow seamlessly together, conveying every emotion through sound. Astell&Kern offers an experience that goes beyond simply "good sound"—it faithfully reproduces the inherent value of the original sound. [The Pinnacle of Pure Resonance] The A&ultima SP4000 Copper embodies Astell&Kern's unwavering belief in pushing boundaries without compromise. It sets a new standard in high-end audio for those who truly understand the essence of pure sound.

Specifications
■Model: A&ultima SP4000 Copper
■Color: Copper
■Body Material: Copper (99.98% Purity)
■Display: 6-inch 2K (2160x1080) Touchscreen
■Dimensions: (W x H x D) 85mm x 149.8mm x 19.5mm
■Weight: Approximately 642g
■Firmware Update: OTA
■Operating Temperature: 0°C to +40°C
■Supported OS: Windows 10 (32/64-bit) 11 (64-bit) / MAC OS X 10.7
■Internal Memory: 256GB [NAND] (including system memory)
■External Memory Support: 1 x microSD slot (up to 2TB)
■Wi-Fi: 802.11 a/b/g/n/ac (2.4/5GHz)
■Bluetooth: V5.0 (A2DP, AVRCP / SBC, AAC, Qualcomm? aptX® HD, LDAC, LHDC)
■Supported File Formats: WAV, FLAC, WMA, MP3, OGG, APE, AAC, ALAC, AIFF, DFF, DSF
■CPU: Octa-core
■DAC: AKM AK4191EQ x 4 + AK4499EX x 4 (Real Quad DAC)
■Supported Sampling Rates:
・PCM Max: 768kHz (16/24/32bit)
・DSD Max: DSD512 (22.4MHz/1bit) Stereo
■Input: USB Type-C (Charging & Data Transfer)
■Output:
・3.5mm 3-pole unbalanced output (also serves as optical digital output)
・4.4mm 5-pole balanced output (5-pole GND connection)
■Output Level: Unbalanced 4.1Vrms / Balanced 8.2Vrms (no load)
■Output Impedance: Unbalanced 3.5mm (0.7Ω) / Balanced 4.4mm (1.7Ω)
■Frequency Response:
・±0.006dB (20Hz~20kHz) Unbalanced / ±0.006dB (20Hz~20kHz) Balanced
・±0.06dB (20Hz~70kHz) Unbalanced / ±0.06dB (20Hz~70kHz) Balanced
■S/N Ratio: 129dB @ 1kHz, Unbalanced / 131dB @ 1kHz, Balanced
■Crosstalk: -136dB @ 1kHz, Unbalanced / -145dB @ 1kHz, Balanced
■THD+N: 0.0005% @ 1kHz, Unbalanced / 0.0003% @ 1kHz, Balanced
■IMD: 0.0004% 800Hz - 10kHz (4:1) Unbalanced / 0.0004% 800Hz 10kHz (4:1) Balanced
■Clock Jitter: 25ps (Typ)
■Reference Clock Jitter: 250fs
■Battery: 6,780mAh 3.8V Lithium Polymer
■Charging Time: Approximately 5 hours (QC 3.0 charging)
■Playback Time: Approximately 10 hours (Normal Mode, FLAC, 44.1KHz/16-bit, Vol. 50, LCD Off, Unbalanced Output)
■Accessories: SP4000 Leather Case, Earphone Carrying Leather Pouch, USB Type-C to Type-C Cable, Screen Protector, MicroSD Card Slot Cover
■Country of Origin: Korea
■Manufacturer's Warranty: 1 year for the product / 90 days for accessories
*Please be sure to keep proof of purchase, such as a receipt, invoice, or dated receipt, along with this product warranty.
*MicroSD card sold separately. Operation with all microSD cards is not guaranteed.
*Operation with all Bluetooth devices is not guaranteed.
*Separate music playback software is required to use the USB-DAC function. Operation with all connected devices is not guaranteed.
*When using USB audio output, operation with all connected devices is not guaranteed.
*This product uses an MTP connection. If using a Mac PC, file transfer software will be required.
*Audio measurements are based on Normal Mode. Auto-mute is not used.
*The above specifications are based on information as of February 2026. They may be changed without notice in the interest of quality improvement.