SMSL AO300 Review

SMSL AO300 Review

SMSL AO300 Review – DAC & Headphone AMP & Power Amplifier

In this review, I’m testing SMSL’s new integrated desktop DAC & headphone AMP & power (speaker) AMP. The SMSL AO300 features a Cirrus Logic CS43131 DAC chip, a subwoofer out, and Hi-Res Bluetooth input. The price is $289.

What’s in the Box

  • SMSL AO300
  • Power cable
  • USB cable
  • Remote control
  • Bluetooth antenna
  • User manual
  • Warranty card


  • A new digital high-power amplifier chip from Infineon, Germany, higher quality with high efficiency and low power consumption
  • Using JRC’s electronic volume control chip NJW1194 from Japan, precise volume control and ultra-low distortion
  • Support MQA decoding and MQA-CD
  • New 3rd generation XMOS XU-316, PCM support up to 32bit/768kHz, DSD support up to DSD256
  • The latest Bluetooth supports LDAC, APTX/HD, SBC, AAC
  • Use the latest audio decoding chip CS43131 by Cirrus Logic
  • All Aluminum alloy CNC precision processing shell, anodizing technology and chamfering process, exquisite workmanship, and delicate touch
  • User-friendly operating system is simple and easy to understand, equipped with full-featured remote control function
  • A large number of professional Hi-fi audio components are used to enhance the sound experience
  • High-quality gold-plated input and output terminals
  • Perfect protection circuit for overheating, overcurrent, etc
  • Built-in high-quality power supply, specially designed for audio
SMSL AO300 Review
Yes, the volume knob is black, taken from my SMSL DO300EX.


  • Input: HDMI(ARC) / RCA/ BT/USB / Optical/ Coaxial
  • THD+N: 0.00003
  • SNR: 107dB
  • Channel separation: 98dB
  • Output power: 165W x 2 (4Ω) and 85W x 2 (8Ω)
  • Input Sensitivity/ Input: Impedance: 280mV/22kΩ
  • USB transmission: USB2.0 (Asynchronous Transfer)
  • USB compatibility: Windows 7/8/8.1/10/11, Mac OSX, Linux
  • MQA decoder: USB/Optical/Coaxial
  • MQA-CD decoder: Optical/Coaxial
  • Power Consumption: 40W (Normal Volume)
  • Size: 219x42x185mm (WxHxD)
  • Weight: 1.52kg/3.35lbs
  • Price: $289

I want to thank Aoshida Audio for providing me with the review sample of SMSL AO300. 


The SMSL AO300 is equipped with a plethora of functionalities, notably including a built-in EQ enabling precise bass and treble tone adjustments ranging from -10 dB to +10 dB. Offering enhanced versatility, the amplifier and headphone amplifier feature two distinct gain settings to accommodate a wider range of audio equipment.

SMSL AO300 Review (4)
The white color of the font can be changed to other colors like green, yellow, orange, red, blue, cyan, and purple.

The SMSL AO300 boasts an expansive array of I/O options, simplifying the process of linking various devices such as computers, set-top boxes, DVD players, as well as smartphones and tablets. Multiple input and output interfaces allow seamless connection to various audio sources and devices, including headphones, speakers, and subwoofers. Bluetooth support for LDAC, APTX/HD, SBC, and AAC, offering wireless connectivity options.

AO300 comes with HDMI (ARC) audio return support. Instead of requiring multiple remotes and potentially even additional cables, ARC allows you to simplify your home theater setup, all while improving your audio quality over older standards. Pair HDMI ARC with HDMI-CEC and you’ll be able to control your home theater system with a single remote rather than two or three. This essentially reduces the need for a universal remote and won’t require you to enter specific remote codes to get everything working. Sadly I couldn’t test this feature because I don’t have a TV.


SMSL AO300 features a floating display window design, like the bigger brother DO300EX, that is accented by a fully bonded, color IPS display screen. This not only adds a layer of sophistication but also provides a dedicated display function. The retro function knob design completes the visual treat, allowing you to navigate effortlessly. A long press of this function/volume knob puts the device on standby and a short press triggers the settings menu on the screen.

Measuring 219x42x185mm (WxDxH), the SMSL AO300 is not the most compact stack SMSL has ever made, but it is smaller than its competitors, assuming it delivers high-end performance.

SMSL AO300 Review

The SMSL AO300 offers 6 inputs including USB, Bluetooth, Optical, Coaxial, RCA, and HDMI(ARC), allowing you to connect to your preferred source effortlessly. It also features 2 headphone outputs (4.4mm, 6.35mm), and 2 Line Outputs (Subwoofer/Speaker).

The quality of the sockets used is great, as expected from SMSL. The sockets seem rigid and durable with no wobble. I do not see any chassis imperfections that could’ve occurred during CNC and there are no assembly issues either. SMSL has been quite consistent in this regard for a long time.

Controls & UI

SMSL AO300’s menu can be accessed with the volume knob or with the remote control that doubles as a joystick. In the standby mode, a single press will power it on and another press will enter its user menu where the following features can be accessed in the settings.

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Sadly you can’t decrease the amount of the light of the IPS screen. It’s either on full brightness or off.

Internals & Power Output

The Cirrus Logic CS43131 DAC ensures superior audio quality with low power consumption, making it ideal for a wide range of headphones. Support for PCM up to 32Bit/768kHz and DSD up to DSD256 for pristine audio playback. Experience dynamic and immersive sound with an impressive 165W x 2 (4Ω) and 85W x 2 (8Ω) output power, delivering high-quality audio reproduction.

SDB Sound

By default, the AO300 arrives in direct mode, and of course, this is the stock tonality of the amplifier. In addition to that, there is the SDB option, Tone, Bass, Super Bass, Rock, Soft, and Clear.

Bass, Super Bass, Rock, Soft, and Clear are options that mainly modify the tone of the amplifier to have a fixed adjustment as described.

SMSL AO300 Review

The more interesting tonality options are in SDB and Tone. SDB is like a loudness button on most other amplifiers, where it follows a version of a Fletcher-Munsen curve compensation where bass and treble are boosted at lower volumes, and proportionately decreased as the volume is increased. This allows for a perceived consistent tonality throughout the different volumes.

SMSL AO300 Review

Tone on the other hand simply allows the user to customize the tonality of the amplifier based on their preference by adjusting bass and treble. The frequency around which the bass and treble adjustments are centered isn’t stated in the manual or the documentation though.


The sound analysis here is based on the headphone AMP output. 

The SMSL AO300 is a true contender as an all-in-one unit for the desktop or stereo system. Its sound signature is characterized by striking clarity and cleanliness, presenting a neutral tonality that remains free of added coloration. Notably, users have the freedom to tailor their listening experience with the built-in EQ, allowing subtle tweaks to bass and treble levels while maintaining the core fidelity.

The SMSL AO300 has a more neutral tuning and comes with a fast yet musical delivery. It’s the typical solid-state kind of sound you’re getting here, and it’s especially noticeable once you start comparing it to the dongles DACs in the same price range on the market. The first character I noticed about the SMSL AO300 sonically was the full-bodied spectrum sound that is wide and tall, rather expansive but with a neutral but slight mid-centric character. It portrays overall a tonality that is rather large in scope.

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The SMSL AO300 is very energetic from top to bottom, especially present in the upper mids and treble regions. Also does well in the detail retrieval department, especially around the midrange section.

The SMSL AO300 tends to be soft-mannered to not emphasize anything within a recording but it’s no mister softie either. It seems to employ a relaxed tuning but a rather spacious one.

The balanced output does indeed have a small sonic improvement over the single-ended output, especially in the overall staging which gives credibility to the almost double and much higher crosstalk specification. It also tends to produce more detail. What I like a lot about the SMSL AO300 are the energy, top-end extension, and the vocal forward presentation. The stereo imaging and left/right balance are also remarkable. Imaging is almost spot on with just a very small amount of underfill but placement makes up for it and the SMSL AO300 portrays an interestingly expansive capability, particularly within the midrange and high frequencies.

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Here we have a neutral bass tuning. The warm bass tonality tends to relax the bass and presents it in a tamed manner but with a good amount of body and low-end extension nonetheless. Bass is fast and it has a good pace and attack. Bass comes with a neutral amount of body, but it’s punchy and impactful. Bass never feels exaggerated in presence. Detail-wise it’s ok, but it’s not the best. Layering on the other hand is impressive and the depth.


The midrange takes front and center stage. The mids perfectly connect to the bass with the same presence, body, and impact. Mids have a neutrally musical presentation with a nice airiness and spacious feel to it. The mid-depth is very good. What I love about the mids are the dynamics, the energetic presentation, the stereo imaging, and the vocals. There’s a focus on the vocals but it’s done excellently. I love this vocal mid-tuning.


The high frequencies also seem controlled and slightly timid, somehow held back from crossing over into distortion levels. Perfectly connecting from the mids, the SMSL AO300 is balanced in the overall presentation. The amount of body is the same as before and what is remarkable here is the liveliness and energy in the delivery. Treble is not the most extended but for me, the treble tuning is the best, together with the mid vocals. I like the SMSL AO300’s sparkle and energy on top.

SMSL AO300 Review 19


The SMSL AO300 boasts an intriguing soundscape, with its soundstage striking a balance between modest width and impressive depth. The layering of audio elements is a standout feature, lending a sense of dimension to the perceived space. This becomes particularly evident when utilizing a higher-end external DAC, which slightly enhances the width of the soundstage.

While the SMSL AO300 may not be characterized as warm, its expressiveness is commendable. The unit manages to deliver a smooth and comfortable auditory journey, perfect for extended listening sessions. This quality makes it a suitable companion for both critical analysis and leisurely enjoyment.

Bluetooth Performance

I haven’t had any audio cut-outs or stuttering. I exclusively used LDAC and Android’s audio quality priority (900-990kbps) Bluetooth mode. The LDAC range is quite good and you get no stutter up to 6-7 meters. AAC & SBC range is 10+ meters.

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In the power-off state, there is a red stand-by light.

In terms of sound, the Bluetooth sound performance is impressive and perhaps one of the best in this price bracket. Of course, it’s not as good as wired, especially from a technical point of view, but you get similar bonuses regardless. In my experience, resolution, in particular, is slightly reduced compared to wired, and the DAC works a little harder to cope with congestion, but I don’t think there’s a noticeable difference in casual listening, although the equipment you’re listening to has a lot to do with it.


In the competitive landscape of audio equipment, the SMSL AO300 all-in-one stands as a testament to the pursuit of sonic precision and versatile functionality.

Its neutral, clean sound signature coupled with an intuitive EQ system offers an engaging listening experience. The dynamic soundstage and expressive qualities further contribute to its appeal. When factoring in its 3-in-1 functionality and compelling price, the SMSL AO300 solidifies its position as a compelling choice for audiophiles seeking an excellent balance between performance and value.


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