About the Astell&Kern A&norma SR25
A great value for high-res music lovers
A great value for high-res music lovers
I had an opportunity to try out the Astell&Kern A&norma SR25 portable player. Its milled aluminum case felt pleasingly cool in my hand, and simultaneously lightweight and substantial. I liked the precise, responsive control of the analog volume wheel, and the elegant simplicity of the touchcreen. But what I really loved most was the sound.
With the SR25, Astell&Kern aims to make a high level of audio performance available to the masses, and what I heard didn't disappoint. Regardless of genre, the music sounded both spacious and full, with an incredible level of detail. Music I had listened to for years suddenly sounded fresh. In some cases, I actually heard things in the music that I had never noticed before.
Firsthand listening impressions
I was impressed with the amount of detail the SR25 provided. Like when I listened to Janos Starker play the Bach Solo Cellos suites, for example. Though a vintage recording (albeit remastered for SACD), I heard fine details like the bow biting into the string, and the soft hum of the sympathetic vibrations in the cello's open strings.
And the sound was equally satisfying listening to Bruno Mars. I heard additional layers in the backing rhythms. The bass was solid, the vocals crystalline. And the soundfield felt spacious enough to "fill the room," even though I was listening through headphones.
Made for high-resolution audio
The SR25 has a quad-core processor for fast and accurate decoding. Dual built-in high-performance DACs — one for each stereo channel - give you bit-perfect playback of high-res files up to 32-bit/384kHz. You also get native playback for 1-bit high-res DSD files up to 11.2MHz. And the player is compatible with MQA, yet another high-resolution format.
Couple the SR25 with a set of high-performance headphones and you're in for a real listening experience. The player has both a standard 3.5mm stereo minijack and a 2.5mm balanced 4-pole output.
Outstanding sound quality
You can play high-resolution downloads from sites like HDtracks without any additional equipment. Even with CD-quality files or compressed formats like MP3, the SR25 can help your music sound its best.
The player's high signal-to-noise ratio and low distortion let the subtle details of your music come through. Plus, its high-fidelity, low-impedance output gives your headphones more power than most portable music players.
Bluetooth® compatible for wireless listening
For wireless listening, the SR25 features built-in Bluetooth. Stream music to your Bluetooth headphones or speakers. The SR25 offers Sony's LDAC high-fidelity wireless music streaming to compatible products, for better sound via a Bluetooth connection.
The player comes with 64GB of internal memory. A microSD card slot lets you add memory cards up to 1TB, for ample storage. And of course, you can have more tunes on extra cards and bring them along for easy swapping.
- compact high-resolution portable music player
- plays MP3, FLAC, WAV, WMA, ALAC, Ogg Vorbis, AAC, AIFF, MQA
- supports files up to 32-bit/384kHz
- native Direct Stream Digital (DSD) playback (.dff and .dsf formats up to 11.2MHz resolution)
- dual high-performance Cirrus Logic DACs (one each for left and right channels)
- powered by a fast quad-core CPU
- frequency response: 20-20,000 Hz
- an ultra-low-noise filter for better sound quality
- Bluetooth-compatible with LDAC high-fidelity wireless music streaming
- built-in Wi-Fi to access home wireless network and internet
- 3.5mm unbalanced headphone output
- 2.5mm balanced 4-pole output for compatible headphones
- 64GB internal flash memory
- microSD card slot for cards up to 1TB (up to 1088GB total memory)
- angled 3.6" color touchscreen
- analog volume wheel provides fine level adjustments
- USB Type-C interface (cable included) for high-speed file transfer and battery charging
- output impedance: 1.8 ohms (3.5mm headphone output), 1.6 ohm (2.5mm balanced output)
- signal to noise ratio: 122dB @ 1kHz unbalanced, 123dB @ 1kHz balanced
- milled aluminum casing
- built-in rechargeable battery offers up to 21 hours of continuous operation
- 2-1/2"W x 4-5/16"H x 5/8"D
- weight: 6.27 oz.
- warranty: 1 year
- Our 60-day money-back guarantee
- MFR # 3PPS217C-CMRDN1
What's in the box:
- Portable digital music player (Crimson Red)
- 40" USB cable (Type A USB on one end and USB-C on other end)
- MicroSD card slot cover
- Protective film
- Quick Start Guide
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More details on the Astell&Kern A&norma SR25
Overview: The Astell&Kern SR25 is a portable high-resolution music player that delivers high quality playback. It is the second model in the A&norma standard line of devices from Astell&Kern, following the SR15. The SR25 features dual DACs (digital-to-audio converters) with balanced and unbalanced analog outputs. It has an internal memory for storing your high-resolution music files, plus a microSD slot for external memory. The SR25 has a large 3.6" LCD touchscreen display, plus built-in Wi-Fi and Bluetooth.
Construction: The compact SR25 is only 2-1/2"W x 4-1/4"H x 5/8"D, and weighs 6.3 ounces. It is made from red aluminum, and features an angled LCD touch screen. The SR25 comes with a protective film to help prevent scratches. Analog controls include a rotary volume knob on the right side, and Play/pause, Previous/rewind, and Next/fast forward buttons along the left side.
Digital Storage: The SR25 has a built-in 64 GB internal memory. You can also insert a microSD card in the external memory card slot on the bottom of the device. The maximum capacity of the microSD card is 1 TB.
Dual DACs: Like its predecessor, the SR25 is equipped with two Cirrus Logic CS43198 Master Hi-Fi level DACs. The SR25 adds a new, faster Quad-Core CPU to make your digital files sound better by removing noise and reducing distortion, and provide a faster, more intuitive user interface. The device plays any resolution of digital files up to 32-bit/384kHz, bit-for-bit. In addition, the device supports native DSD256 playback. The SR25 supports the following Audio Formats and Bit Rates:
- Audio Formats: WAV, FLAC, WMA, MP3, OGG, APE, AAC, ALAC, AIFF, DFF, DSF, MQA
- Sampling Rates:
- PCM: 8kHz - 384kHz (8/16/24/32 bits per sample)
- DSD Native: DSD64 (1-bit/2.8MHz), Stereo / DSD128 (1-bit/5.6MHz) Stereo / DSD256 (1-bit 11.2MHz), Stereo
USB DAC Mode: The USB DAC function lets you connect the SR25 for use as a sound card for your computer for better sound quality, compared to the built-in sound card. Connect the unit via USB from your computer and listen to your stored digital music with headphones, powered speakers, or on your home stereo. The USB DAC is compatible with 32- and 64-bit versions of Windows 7, Windows 8, and Windows 10, and Mac OS X 10.7 (Lion) or later. In USB DAC mode, the device supports PCM 8-394kHz (8/16/24-bit) and DSD (2.8/5.6/11.2 MHz). Volume is controlled via the SR25's volume wheel. You may need to install a dedicated driver (available on Astell&Kern's website) to use the SR25 as a USB DAC.
Balanced/Unbalanced Outputs: The Astell&Kern SR25 offers both balanced and unbalanced outputs on the top of the device. Balanced outputs have an additional "cold" signal to compliment the hot signal, which reduces external noise and increases output. The balanced output is a 4-pole 2.5mm port. You can also connect an external audio device to the SR25 by connecting to both the earphones port (ground) and the balanced port (LR), using an optional balanced cable available from Astell&Kern. Output voltages: Balanced 4.0V, Unbalanced 2.0V (no load).
User Interface: The SR25 features a high-quality user interface to make it easy to find and select your music files, change the volume, and adjust the sound:
- 3.6" LCD Touchscreen: The full-color 3.6" LCD touchscreen has a resolution of 720 x 1280 pixels. The screen displays the title and artist of the currently playing song, along with elapsed and remaining time, with the album art in the background. On the touchscreen, you can touch the Play/Pause, Previous/Rewind, or Next/Fast Forward icons to control playback. You can make adjustments to the EQ, set the repeat and random modes, and add the song to a playlist, all using the touchscreen interface.
- Rotary Volume Knob: The SR25 has a side-mounted analog-style rotary volume knob. As you adjust the volume, you can feel and hear the detents in the rotary knob, and view the volume range numerically and graphically on the display (0 to 150). In the menu, you can change the output to "Line Out", which locks the volume level at maximum.
- Hardware Control Buttons: There are four physical buttons on the unit: a top-mounted power button, along with side-mounted Play/Pause, Previous/Rewind, and Next/Fast Forward buttons. The power button turns off the screen with a short press, and turns the power on/off with a longer press.
Equalizer: The SR25's built-in 20-band equalizer that lets you adjust each band ±5.0dB in 0.1dB increments. In the advanced settings, you can adjust the bandwidth (Q) from 2.0 (wide) to 4.0 (narrow). You can save up to 20 User EQ curves.
Gapless Playback: Gapless Playback allows you to play one song after another without interruption. This is only supported when playing music files with identical bit rates, sample rates, and channels.
USB-C: The SR25 has a USB Type-C port on the bottom of the unit for connecting the unit to your computer for computer data transfer and for charging the battery. A Type-C to Type-C is recommended when connecting to a Mac that supports USB Type-C.
Wi-Fi Capability: The SR25 features built-in Wi-Fi (802.11 b/g/n--2.4GHz), allowing you to connect the device and your computer to the same network for streaming and downloading music. The device must also be connected to Wi-Fi to search the Gracenote database. With the MQS Streaming Server software installed on your PC or Mac, you can use the SR25 to access music files stored on your computer's hard drive or a connected HDD. In addition, the Wi-Fi connection allows you to receive notifications of new available firmware updates (OTA Upgrades), allowing you to download them on the spot.
Bluetooth: The SR25 also has built-in Bluetooth V4.2 with LDAC, AVRCP, A2DP and aptX HD profiles for connecting a Bluetooth device to listen to music wirelessly. The LDAC codec gives you more options for higher quality wireless audio. To pair the device, you must place the unit within 8" of the Bluetooth device. The connection and audio quality will degrade at longer distances, and may disconnect at distances of 6-1/2 feet or more.
AK Connect 2.0: The SR25 can stream or download music files stored on a computer on the same network. Using the AK Connect 2.0 app (available for Apple devices running iOS 8.0 or later or Android devices running version 4.2 and up), you can connect to a NAS or PC and control it with a smartphone or tablet. The app is compatible with DLNA and UPnP. (Streaming music from services such as TIDAL will be available soon.)
Power Requirements: The SR25 is equipped with a 3150 mAh 3.7V Lithium-Polymer battery. The battery charges via USB in about 2.5 hours via the included USB Type-C cable (5V-2A USB adapter). A fully charged battery can provide up to approximately 21 hours of continuous playback time (based on FLAC, 16-bit, 44.1kHz, unbalanced output, volume 50, EQ off, LCD off). The Auto Power Off feature helps save battery life by turning off the device if there's no user input for a defined period (10 minutes to 24 hours). A sleep timer (10 minutes to 5 hours) and screen timeout (10 seconds to 3 minutes) are also available.
Protective Film: The unit includes a protective film to keep the touchscreen and the rear glass panel scratch-free.
- Frequency Response:
- 20Hz-20kHz (±0.014dB Unbalanced, ±0.011dB Balanced)
- 20Hz-70kHz (±0.10dB Unbalanced, ±0.12dB Balanced)
- Signal-to-Noise Ratio (@1kHz): 122dB (unbalanced); 123dB (balanced)
- Crosstalk (@1kHz): 138dB unbalanced, 144dB balanced
- THD+N (@1kHz): 0.0007% unbalanced, 0.0008% balanced
- Clock Jitter: 25ps