Astell&Kern has created some of the greatest DAPs in the world, and while they’re constantly pushing new and different innovations with their players, often those innovations don’t pan out. While features like dual signal chains with separate outputs in a single portable DAP or swappable DAC/Amp cards were cool, they’ve seen very little follow-up from Astell&Kern, while the brand’s core lineup of simple, player-first designs has yielded continued success. PD20 is their latest twist on your typical DAP, and offers some new design elements with one feature in particular that might become a new standard in the industry.
Build and Design
PD20 is like the opposite side of the coin from Astell&Kern’s flagship SP4000. Where SP4000 is all sharp lines and shiny metal, PD20 is simple, lightweight, and where SP4000 keeps the hardware layout down to the essentials, PD20 adds a few more knobs and switches. The small details still feel very much like A&K, but there’s a simplicity and practicality to the device that differs from typical A&K designs.
In the package, Astell&Kern only provides the essentials, with a clean simple unboxing experience. Inside you just get the charge cable, warranty card, screen protectors, and manual. The device itself features 3.5mm and 4.4mm analog outputs and USB-C for charging or digital output. On the side of the device there are two switches for the Triple Amp Architecture that lets you select the Amp Class (A, A/B, or Hybrid) and Current (High, Medium, or Low.) The amp and current selection will have a pretty big impact on your battery life, with Class AB and Low Current offering better than 10 hours of battery life, while Class A and High Current will have you closer to the 5 hour range.
On top you have one knob that controls the volume, and another for PD20’s most notable feature: the Sound Master Wheel. The Sound Master Wheel, lets you specifically adjust the Bass, Mids, and Treble to quickly and easily tune your sound.
Using PD20
PD20 follows in SP4000’s footsteps in offering a player-first OS design that adds the convenience of full Android app support. At first glance, you get what looks like a classic Astell&Kern design, dedicated to library management and playback, but open the App Drawer and the Google Play Store is preinstalled, allowing you to install and use just about any app that’s out there.
While the primary purpose of this is to install various streaming services or music players, you can also install games, social media apps, or video streaming services to use the device however you like. It seems that support has improved since the launch of SP4000, because every app I thought to try, including Clash Royale, TikTok, and Netflix all ran well on the device. With the 6 inch 1080p screen, the ability to load PD20 up with any kind of media – or store it on a microSD card – to watch on a long trip adds a new dimension to the PD20’s capabilities that previous generations haven’t had.
PD20 also includes a full sound personalization suite with a hearing test. The test determines Your left and right balance across the full frequency spectrum, and then there are additional settings for equalizer and Audiosphere configuration. Audiosphere provides an enhanced imaging effect, but I didn't real like using it in most cases. The system can also save profiles, so you can either share the device without worrying about getting someone else's profile, or use it to quickly switch between basic EQ and Audiosphere settings for different genres or headphones.
There are a number of features that you can access through the OS, including the equalizer, crossfeed, and various upsampling and DAC tuning options, like DAR. Astell&Kern’s crossfeed features are among the most comprehensive on the market, and the EQ offers a full parametric EQ that can work in conjunction with the simpler Sound Master Wheel. It all comes together to deliver exceptional sonic flexibility. But does it sound good?
Sound
PD20 uses a quad ES9027PRO DAC configuration to deliver a clean, detailed sound that layers in the classic Astell&Kern natural musicality and smoothness with accuracy and resolution. PD20 is exceedingly close to the sort of pure flagship sound you get from $4k+ players like SP4000 or the top of line from Cayin or Luxury & Precision, but doesn’t quite reach those same heights in terms of the pure realism in imaging and the delivery of the most intricate of details.
The amp selection is also important here with Class A giving you the punchiest, most energetic sound, while Class AB is smoother, and Hybrid lands somewhere in between. Current selection is most important with over-ear headphones, but some power hungry IEMs, like the Elysian Annihilator or FATfreq Grand Maestro gain some benefit from High Current mode. PD20 does surprisingly well with some moderately hard to drive headphones, but it’s still not a solution for the hardest to drive headphones.
All of the key aspects to the sound here are excellent, with strong detail, good separation, and a good general tuning balance. The general tuning pairs well with PD20’s strong imaging characteristics and three-dimensional soundstage presentation. There’s decent weight and body to the sound, and Class A mode provides the most vivid imaging presentation, while AB feels a little more diffuse, with less body to the sound.
While the key sonic characteristics are strong, it’s the Sound Master Wheel that’s PD20’s real differentiator. It’s funny how so many old CD players, car stereos, or integrated amp have had some form of a simple Bass, Mids, and Treble control that lets users make basic tweaks to the sound, and how few audiophile devices have implemented the same thing. The Sound Master Wheel offers a simple clean option for either a small tweak or massive change to the sound. As long as you don’t push it too far, the changes generally sound pretty natural, whether it’s a bass boost, a little extra treble, or you’re trying to bring out more vocals in the mids. Using the feature is intuitive and the results are hard to mess up.
Comparisons: Astell&Kern SP4000 ($4290), iBasso DX340 ($1999)
PD20 definitely provides excellent sound quality So is PD20 like a mini-SP4000? And how does it stack up to some of the competition in its class like the iBasso DX340? The comparison here is interesting because it doesn’t necessarily come down to features or pure sound quality, but instead, a little bit of each. Compared with SP4000, PD20 is a much more practical design, that’s lighter, has more features, and has a much longer battery life, but doesn’t quite match the sound quality. Compared with DX340, PD20 has a different character to the sound, and a set of features that is likely to appeal to a different audience.
In terms of sound, SP4000 has the strongest pure sound quality, with the strongest detail, most holographic imaging, and most three-dimensional soundstage. DX340 is a close second, but some aspects depend on the amp card you’re using, with options like Amp16 offering a more holographic sound, while Amp17 delivers better dynamics with over-ear headphones. PD20 is just behind DX340, and gains some points for having a simpler method for adjusting sound characteristics, rather than needing a screwdriver and replacement cards.
For features, PD20 is going to provide the best overall user experience, and provides the biggest showstopper of a feature in the Sound Master Wheel. The combination of overall sound that’s competitive with others in this class and the ability to change amp classes, current level, and general tuning at your fingertips makes PD20 a really strong contender.
The Bottom Line
I’ve tested pretty much every amp released by Astell&Kern for the last 6 years, and PD20 feels like a quiet revolution. As EQ becomes more popular among the community, while many don’t want to dive into the complexity required to use a parametric EQ well, having basic EQ options at the touch of a button is a class-defining feature, and having that feature built into an overall solid DAP – with a number of other strong features – makes PD20 an excellent new contender in a crowded market.
