Tech
Astell&Kern PD20 Is the First DAP That Tunes Music to Your Hearing with Audiodo Personal Sound
Astell&Kern’s PD20 arrives as the clearest signal yet that the Korean manufacturer still sets the standard in the high end DAP category. For more than a decade, Astell&Kern has defined what a reference portable player should look like, feel like, and most importantly, sound like. With the PD20, the company is not chasing trends. It is extending its lead.
What makes the PD20 different is its integrated Personal Sound system developed with Audiodo, allowing the player to create a listening profile based on the user’s individual hearing characteristics. Personalized audio is not new. Wireless headphones have offered hearing compensation for years. But bringing true left and right ear analysis and correction to a dedicated digital audio player is new territory. Instead of delivering a fixed house sound, the PD20 reshapes the presentation around the listener, raising the bar for what a flagship DAP can do.
Personal Sound System Brings True Hearing Calibration
The PD20 features a Personal Sound system developed in collaboration with Audiodo. The player analyzes the listener’s hearing characteristics and applies independent compensation for the left and right ears, creating a personalized listening profile based on measurable data rather than preset EQ curves.
To enable accurate calibration, Astell&Kern includes dedicated earphones with the PD20 that work in tandem with an integrated hearing test. The process evaluates sensitivity across frequencies and builds a correction profile tailored to the individual user. The result is a sound signature optimized specifically for that listener’s hearing response.
For additional control, the PD20 incorporates a Sound Master Wheel that provides 160 step adjustment from -8.0 dB to +8.0 dB across Bass, Mid, and Treble bands. This allows for precise real time tonal refinement without interrupting playback, giving users both automated personalization and manual tuning flexibility.
Advanced Amplification Architecture
The PD20 features a Triple AMP architecture with real time switching between three distinct amplification modes Class A, Class A/B, and Hybrid, allowing users to select the presentation that best matches their headphones and listening preferences. Each mode alters bias operation and output behavior to prioritize tonal richness, efficiency, or a balance of both, as outlined in the accompanying image.
- Class A Mode: Delivers a rich, high density presentation with minimal distortion, emphasizing tonal weight and a smooth, analog like character.
- Class A/B Mode: Prioritizes balance and efficiency, offering strong dynamic stability with clean, articulate detail across the frequency range.
- Hybrid Mode: Blends the tonal refinement of Class A with the efficiency and output capability of Class A/B, aiming for a balanced presentation that combines texture, control, and usable power.
Precision Bias Control for Class A and Hybrid Amplification Modes
A dedicated physical slide switch allows instant mode changes without diving into menus. In Class A and Hybrid modes, users can further adjust amplifier current across three selectable levels to better match headphone load and listening preference.
High: Maximizes output current for greater headroom and dynamic impact. This setting is designed to better control high impedance headphones, delivering a broader soundstage with strong drive and stability.
Mid: Strikes a balance between current output and efficiency, maintaining tonal density while preserving clarity and resolution. It is positioned as the most versatile setting for a wide range of full size headphones.
Low: Reduces output current to lower the noise floor and improve control with high sensitivity earphones. This setting is optimized for IEMs, helping reveal low level detail without introducing unwanted background noise.
Sound Lab Control
The PD20 is conceived as a true sound lab. Built around what Astell&Kern calls Sound Lab Control, the player draws inspiration from professional studio gear in both layout and operation. Dual top mounted wheels separate sound tuning from volume control, while dedicated slide switches manage amplifier mode and current selection. LED lighting provides real time indication of track bit depth and active operating modes, offering clear visual feedback during playback.
DAC: The PD20 is built around the ESS ES9027PRO in a Quad DAC configuration, with four DACs operating independently to reduce inter channel interference and improve signal separation. This architecture is designed to maximize channel balance, resolution, and overall dynamic performance. The PD20 can also function as a USB DAC when connected to a Mac or Windows based PC, extending its use beyond portable playback.
ESA Enhanced Signal Alignment: The PD20 incorporates Astell&Kern’s proprietary ESA technology, which focuses on minimizing group delay by precisely aligning frequency signals across the spectrum. The goal is lower distortion and improved clarity through more accurate time domain performance.
Advanced DAR: Astell&Kern’s second-generation Digital Audio Remaster technology, first introduced on the flagship SP4000, is engineered to produce a more natural and refined presentation. Instead of routing the signal directly to the DAR engine, audio first passes through VSE (Virtual Sound Extender), where missing harmonics are algorithmically reconstructed to enhance tonal completeness. After this stage, DAR processing applies up-sampling for more comprehensive signal refinement. The combined process is designed to improve depth and immersion while preserving the integrity of the original recording.
Atmosphere Technology: The PD20 incorporates Atmosphere processing that expands beyond traditional 2-channel stereo. It creates a virtual 3-dimensional sound field from standard stereo content and offers four selectable presets: Subtle, Balanced, Immersive, and Echoic. Depending on the material and listener preference, users can tailor spatial presentation for music, orchestral works, or audio/video content.
Memory and Networking: The PD20 includes 256GB of internal storage and supports microSD cards up to 2TB. Connectivity features include dual-band 2.4GHz/5GHz Wi-Fi (a/b/g/n/ac), DLNA networking, USB digital-audio output, and USB-C for data transfer and charging.
PCM and DSD: The PD20 supports native playback of high-res PCM music up to 32-bit, 768kHz, and DSD512.
ReplayGain and AK File Drop: Replay Gain keeps playback levels consistent across tracks, while AK File Drop enables seamless, wireless file transfers from devices on the same network with no cables required.
Bluetooth Support: The PD20 incorporates Bluetooth with support for aptX HD, LDAC, and BT Sink mode. BT Sink allows the PD20 to receive audio from an external device over Bluetooth and operate as a Bluetooth DAC. This enables music streamed from a smartphone, tablet, or other source to benefit from the PD20’s internal DAC architecture and amplification stage.
Analog Outputs: The PD20 provides both 3.5mm single ended and 4.4mm balanced headphone outputs, ensuring compatibility with a wide range of headphones, earphones, and in-ear monitors.
Fast Charging: USB PD 3.0 fast-charging support allows the PD20 to reach a full charge in approximately 3.5 hours when used with its included charging cradle and a compatible USB-C power adapter.
Crossfeed: In headphone listening, where left and right channels are fully isolated, long sessions can increase listening fatigue. The PD20’s Crossfeed function blends a controlled portion of each channel into the other with a slight time delay, helping to center the sound image and simulate a more speaker-like presentation. Adjustable parameters include Shelf Cutoff, Shelf Gain, and Mixer Level, allowing users to fine tune the degree of crossfeed to match their listening preferences.
Display: The PD20 features a 6-inch FHD+ display that presents playback status and operational controls with clear visibility and responsive touch interaction.
Pro Tip: The PD20 will be Roon Ready, pending Roon testing and certification.
The Bottom Line
The Astell&Kern PD20 strengthens the brand’s position at the top of the DAP category by introducing something genuinely new for dedicated players: integrated hearing based personalization. While custom sound profiles have existed in wireless headphones, bringing left and right ear analysis into a Quad DAC, multi mode amplification platform is a first for a reference grade DAP.
Add selectable Class A, Class A/B, and Hybrid amplification, adjustable bias current, second generation DAR processing, and extensive manual tuning, and the PD20 becomes a highly configurable portable source built for serious listening.
Priced just under $2000, it undercuts the SP4000 while offering a feature the flagship does not. The PD20 is for experienced headphone users who want reference performance with flexibility and control, and who understand that hearing is not universal. If the idea of a DAP that adapts to you makes sense, the PD20 is one of the most forward thinking players currently available.
For those wondering about the fate of the PD10, the PD20 is not a replacement. The PD10 remains a current model and continues in production alongside the new player.
The key difference between the two centers on DAC architecture. The PD10 is built around dual AKM4191EQ modulators paired with four AKM4498EX DAC chips in a dual DAC configuration, reflecting AKM’s separated digital and analog design philosophy. The PD20, by contrast, adopts four ESS ES9027PRO DACs in a Quad DAC layout, representing a different technical approach within the lineup rather than a generational shift.
Price & Availability
The Astell&Kern PD20 DAP will be available in late March 2026 through Astell & Kern Authorized Dealers, with a suggested retail price of $1,970 (£1799).
For more information: astellnkern.com