Do consumers really need a DAP in 2023? That might seem like a rather defeatist way to start to a review of the Astell&Kern SR35 — but it is also a fair question. 99% of consumers are perfectly content with using their smartphone to stream digital music and if that is how they roll — nothing I am going to write about the SR35 is going to convince them otherwise.
That’s a pity because DAPs today fulfill multiple roles when it comes to hi-fi playback and that includes their ability to stream hi-res music wirelessly to a wide range of headphones. They can also serve as your digital hub at home or when driving. Does multi-room audio interest you? Or how about outdoor listening in the backyard as you catch up on work emails or take phone calls.
The DAP space has actually expanded in 2023 with high-end options from Cayin, FiiO, Sony, Hiby, Shanling, Lotoo, Luxury & Precision, and iBasso.
But any serious discussion about DAPs has to begin with Astell&Kern which is celebrating its 10th anniversary this year; the Korean high-end manufacturer was started by iRiver (which has now changed to Dreamus) and many consumers will remember that they offered one of the first and most competitive alternatives to the Apple iPod.
Sony and Astell&Kern created the high-end DAP just as the Head-Fi revolution was finding its sea legs and have been major players for over a decade.
A&K offers a rather wide range of DAPs including the A&ultima, A&futura, KANN, and entry-level A&norma series.
Astell&Kern has not scored a Stanley Cup winning goal with every single product over the past decade, but most within the Head-Fi community (where there are a million opinions about everything…sounds familiar) would agree that brand has introduced state-of-the-art players that forced its competition to come up with something comparable or superior — and that has not always been easy to accomplish.
The entry-level A&norma lineup are Astell&Kern’s more affordable series of DAPs, but that does not mean that there is not a lot of high-end technology packed into these little black boxes and that you’re getting a vastly inferior product for $799 USD.
A lot of the technology that first appeared in the more expensive A&futura and A&ultima products has trickled down over time into products like the SR35 DAP.
The new digital audio player builds on the success of the SR25, and SR25 MKII players that replaced the venerable AK70 MKII; EIC Ian White owned that specific player for 4 years before donating it to his eldest as she headed off for 2 years on a Kibbutz in Northern Israel.
Technology
What stands out abut the Astell&Kern SR35 is the size and weight; compared to other DAPs currently available, it is on the smaller side and that might appeal to some who are on the fence in regard to carrying around another device. The player is 4″H x 2.5″W x 0.5″D and weighs only 6.5 ounces.
The shell is machined from aluminum with glass front and rear plates. A&K have integrated a 3.6″ 720×1280 resolution screen into the case that actually sits on an angle. That might look strange to potential new customers, but it has been a trademark of their players along with an angular frame for quite some time.
The top surface of the player features 2.5mm, 4.4mm and 3.5mm headphone jacks from right to left. Having all 3 types will appeal to those IEM and headphone users who desire both single-ended and balanced connections and one should expect that for $799.
There is a large volume knob on the right side and four buttons on the left (power, back, play/pause, forward from top to bottom). The bottom panel includes a USB Type-C port for charging and data transfer along with a micro-SD card slot (which supports cards up to 1TB) for expanding its 64GB of internal storage.
The overall finish and build quality is quite good; A&K made sure to radius any sharp edges and the anodizing on the aluminum is nice and even throughout including the volume knob which is well matched to the frame.
The rest of the package includes a charging cable, screen protector, and a quick-start guide. A leather carrying case ($99) is not included but is something that we would recommend from Astell&Kern or a number of other third-party vendors.
Internal Technology and Battery
Very much like the Cayin N7 DAP that we just reviewed, the SR35 features some important upgrades that really matter in terms of performance.
The aforementioned 64GB of internal memory is shared between the OS and storage, a quad-core CPU handles the processing duties, whilst communication is handled by dual-band WiFi (2.4 and 5 GHz) and there is Bluetooth codec support for AAC, aptX HD, and LDAC.
Music tasks are managed by a Teraton Alpha module of A&K’s design that handles the three distinct portions of audio playback. The first is power management which delivers clean, noise free power to the other two primary components and manages battery life.
The DAC integrates 4 Cirrus Logic 43198 DAC chips; the SR35 supports 32-bit/384kHz PCM, DSD256, and MQA for TIDAL Master recordings.
The headphone amplifier is a new version of the circuit first introduced in the A&K SR25 MKII DAP; this latest iteration offers almost double the power of the SR25 MKII without sacrificing battery performance.
Astell&Kern accomplished this by offering two gain levels; the SR35 can operate at the same output level as the SR25 MkII and offer listeners 20 hours of battery life, or when more power is needed, the SR35 offers high gain which increases output power to 3Vrms single-ended and 6Vrms balanced.
This allows the SR35 a greater range of usable headphones than the SR25 MkII without sacrificing battery life or noise floor in the process. This new amplifier was introduced in the A&ultima line with the SP series players and has now trickled down into the A&norma line for the first time.
The battery is a 3175mAh Lithium Ion cell and takes under 3 hours to charge from depletion. The SR35 does not support wireless charging though, so you’ll need the provided USB cable.
User Interface and Controls
The most anticipated feature of the new SR35 is the Crimson UI; this is only the second DAP in the entire A&K lineup to utilize the new interface outside of the flagship SP3000 that we reviewed in Q4 2022.
The new UI represents a massive overhaul of the interface and library management functions; the responsiveness of the SP3000 was significantly better than previous products and we expect to see Crimson on all future DAPs from the manufacturer.
The one thing that hobbles the SR35 somewhat compared to the SP3000 is its limited processing horsepower so it was not reasonable to expect that it would perform as well. The SP2000 feels almost lethargic compared to the SP3000 with Crimson, and that was similar to how an older SR25 performed compared to the new SR35.
The only place where I found a bit of a lag was in loading the album art during and after the initial read of an SD card. The more files present, the longer the delay in getting all of the album art loaded.
Once loaded it performed well, but do know that during the initial scan and in the immediate aftermath, there are a lot of background tasks running that can bog down the UI so it may be best to insert a new SD card and either load in a few files at a time via USB or plan on giving the player 10 minutes to complete the load as my 512GB card with 8000+ files really slowed it down.
The SR35 supports both 2.4 and 5 GHz wireless connectivity and V-Link; it also supports TIDAL natively. If you wish to add other streaming platforms, Astell&Kern also offers installs of several additional streaming apps via the services menu.
The current list includes Spotify, Amazon Music, Apple Music, Qobuz, Deezer, Flo, and a handful of other regional offerings.
The SR35 is also Roon-Ready which is a first for the A&Norma line as well but those savvy with Roon will know that Roon-Ready does not mean the SR35 works as a Roon Controller.
I had no issue using the SR35 as a Roon-Endpoint, playing material off my main system through the SR35, but it does not offer the ability to connect directly to a library and use the player both as endpoint and controller (Something I’m prone to do with my Phone and a dongle DAC at times).
Another small gripe is the screen size; those with larger hands might find that they make more mistakes on the keyboard while performing searches. We have become accustomed to larger screens on smartphones and DAPs and this trade-off had to be made to keep the player smaller and more affordable.
Sound
With a $799 USD asking price, it made sense to use the SR35 with as many high-end IEMs and headphones as I could over a period of a few weeks; including the Letshuoer Cadenza 12, UE Live, Campfire Andromeda, Beyerdynamic T5p (2nd generation), HiFiMAN Arya Stealth, and the Fostex TH900.
The overall tuning is extremely neutral with some sharp edges rounded off; where it does depart from its neutral tonal balance and presentation it becomes somewhat laid back sounding.
The sub-bass range is delivered with solid extension and impact where it exists on the recording and most of the range was reproduced rather cleanly and with ample texture.
The bass response is certainly not overly thick and it never felt as if the bass range was overly emphasized. The SR35 will not add any additional weight to bass notes or add bass information to fool you into thinking that your headphones can deliver deeper low end response.
The upper bass and lower midrange are both very clean and detailed sounding; male vocals have accurate sounding timbre and note weight and voices higher in the range sound extremely natural.
Guitar and violin notes come across with enough presence and timbre to sound rather realistic, but this is also where one notices a gap between really good DAPs like the SR35 and exceptional ones like the Cayin N7 and Astell&Kern SP3000.
The N7 and SP3000 offer superior resolution, top end performance, and overall clarity.
Treble performance is another strong aspect of the SR35’s performance; the highest notes have good energy and detail without sounding strident or being brought too far forward in the mix. Percussion snap is crisp and cymbals have more than enough energy and never came across as metallic sounding which is somewhat unusual with such a wide range of IEMs and headphones.
There is a slight smoothing over of detail that is typical of designs that use the Cirrus Logic chips; the silver lining is that the SR35 has a very pleasant, non-fatiguing presentation that worked well with a lot of music and overly analytical sounding headphones.
Background noise was superbly low through the SR35; IEMs like the Campfire Audio Andromeda are known for hiss and we had to turn the volume all the way up with the music stopped to discern any. With high-sensitivity IEMs and headphones, the noise floor was subterranean and one can truly hear so much deeper into recordings using the low gain setting. Impressive at this price point.
As I mentioned in my review of the Cayin N7, soundstage performance and imaging really depends on the IEMs and headphones on the other end of the DAP; the SR35 doesn’t quite perform at the same level as the N7 or SP3000 in that regard, but I never felt as if the soundstage was too small or shallow. Imaging was rock solid with most recordings and the stereo separation was excellent.
Conclusion
The Astell&Kern SR35 is almost $3,200 less expensive than the flagship SP3000 and it would be unreasonable to expect the entry-level DAP in the lineup to better the reference level product from the same manufacturer. Why would anyone buy the more expensive product if that were the case.
However, it would be accurate to describe the SR35 as a scaled back version of the SP3000 when it comes to the design, UI, and overall sonic performance. The two DAPs share a similar tonal balance; the SR35 is slightly darker sounding with less presence in the midrange and treble.
The SR35 does not offer the same level of refinement, detail, or resolution of the SP3000 but most listening sessions conducted whilst commuting or traveling are really not going to permit that level of focus with full-sized headphones.
But when it comes to size, usability, battery performance, and sound quality — the SR35 really makes a strong case for itself.
The SP3000 is more transportable than portable and not something you are going to easily vanish in your suit pocket or jeans.
With a battery life of almost 20 hours with IEMs, the SR35 is the logical high-end DAP option for the commuter or business traveler; especially for those who have zero desire to spend over $2,000 on a DAP.
As someone who carries an Astell&Kern KANN Alpha DAP on him while commuting and during business travel, the SR35 is the most obvious replacement because of its superior battery performance, cleaner UI, and massive reduction in weight.
Where to buy: $799 at headphones.com
