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SMSL D400 MK2 Desktop DAC Review

A desktop DAC pairing an AK4191 processing chip with an AK4499EX conversion chip and a built-in 10MHz OCXO clock, listed at $649 in black or silver. It suits buyers who want six input types and XLR plus RCA outputs, with figures that are the page's own.

3.4Editorial rating: 3.4 out of 5Editorial rating · research-basedUpdated October 28, 2026
$649Price checked October 29, 2026
Check price at HiFiGO

Our verdict

Worth considering for buyers who want an AKM-based desktop DAC at $649 with six input types, XLR and RCA outputs and a built-in OCXO. Look elsewhere if you need an output level, size or weight before buying, or an independent test, as none was checked for this review. The page's praise for the sound is its own wording and is not checked here.

Best for
Buyers who want an AKM chip pair, a built-in OCXO and XLR plus RCA outputs in one desktop DAC.
Skip if
You need output level, size or weight figures, which the page text does not give.

Why 3.4/5: Held back by a page with no specification list as text, by the store's own terms contradicting each other, and because no independent test of this model was checked for this review.

The page calls the D400 MK2 the successor in SMSL's D400 series; it is listed at $649. Per the page, an AKM AK4191 handles digital filtering and processing while an AK4499EX does the conversion, backed by a built-in 10MHz OCXO specified at ±5 ppb and a self-developed CK-04 clock circuit. It takes USB, Optical, Coaxial, I2S, AES/EBU and Bluetooth inputs and gives XLR and RCA outputs. The page quotes 0.00006% THD+N and 132dB dynamic range on the balanced output.

Specifications

SpecPage says
DAC chipsAK4191 (digital processing) + AK4499EX (analog conversion)
THD+N0.00006%(-124dB unweighted)
Dynamic range132dB (balanced XLR output)
USB processorXMOS XU316, 3rd generation
PCMUp to 32-Bit/768kHz
DSDNative, up to DSD512
MQAMQA and MQA-CD hardware decoding via USB, Optical, Coaxial
ClockBuilt-in 10MHz OCXO, ±5 ppb; CK-04 clock circuit
InputsUSB, Optical, Coaxial, I2S, AES/EBU, Bluetooth
OutputsXLR and RCA
Bluetooth codecsLDAC (up to 24-bit/96kHz), aptX-HD, aptX, SBC, AAC
Analog stageFive dual op-amps
DisplayFully laminated color IPS display with tempered glass
ControlsRemote control; DSD Direct Access (DSD bypass)

Options and pricing

The two options are D400 MK2 Black and D400 MK2 Silver, each $649 and orderable when the page was read. The page says a full-featured remote control is included but its text does not mention a power cord, cables or plug type, so the rest of the contents is not stated there.

How it compares

The TOPPING D70Pro costs $699 and uses an ES9039SPRO chip with Bluetooth 5.1 in its title, where the D400 MK2 at $649 uses an AKM chip pair with a built-in OCXO and its page text gives no Bluetooth version. The SMSL SU-9 PRO is $499.99 with two ES9039M Pro chips. The D400 MK2 suits buyers who want the AKM architecture and an internal OCXO; the SU-9 PRO suits a smaller budget.

Shipping, returns and warranty

HiFiGO sells from hifigo.com and says every order leaves its warehouse in China, usually 1-3 business days after it is placed, and says its delivery times are estimates, not promises. Its shipping policy gives the United States 1-2 weeks (about 10 days on average) by Priority and 6-10 days by Premium, both with duties and taxes prepaid by the store; Canada 2-3 weeks; the United Kingdom 1-2 weeks; and Australia 10-15 days. Express couriers (DHL, UPS, FedEx) take 3-7 days, but then the buyer pays any duties and taxes. No shipping page names New Zealand, PO boxes are not accepted, and the free-shipping thresholds differ between the store's own pages, so check the cart. One of its two shipping pages adds that a lost parcel on an order above $50 gets only a 50% refund. A US buyer reported a $40 tariff charge in August 2025, after which HiFiGO said it had added a customs notice at checkout.

Read the return terms before you order. The homepage advertises 7-day returns. Both of HiFiGO's policy pages offer a 7-day dead-on-arrival cover (a replacement or a full refund, with the return postage refunded) and also describe 30-day returns, but a request made 7 to 30 days after delivery loses 30% of the MSRP as a restocking fee (10% more if the packaging is incomplete), plus shipping both ways and duties, and the FAQ on the same pages says there is no refund or exchange once 7 days have passed. One version recommends reselling an opened product locally. Custom IEMs and custom cables cannot be returned, no return address is published, and buyers describe sending items back to China.

HiFiGO's warranty runs one year from the order date for parts and labor; its policy names desktop DACs and amps, IEMs and dongles at one year and gives cables and adapters three months. HiFiGO decides between repair and replacement, the buyer pays the shipping, and faulty items go back for service, not for a refund. Claims go to [email protected], the only contact the store lists: its pages name no company, street address or phone, and its terms are governed by the laws of China.

On Trustpilot, HiFiGO had 4.6 out of 5 from 378 reviews when we checked on 2026-10-28 (91% five-star, 5% one-star), and it had replied to about 75% of negative reviews; Trustpilot notes the store has not invited customers to review recently. The one-star reviews mostly concern the short return window and the deductions on returns, items listed in stock that turned out back-ordered, slow email support and a tariff charge on a US delivery in 2025. HiFiGO says its products are genuine and come in the brands' retail packaging; it does not claim to be an authorized dealer.

What we liked

  • AK4191 and AK4499EX split digital processing from conversion, per the page
  • Built-in 10MHz OCXO specified at ±5 ppb
  • Six input types: USB, Optical, Coaxial, I2S, AES/EBU and Bluetooth
  • XLR and RCA outputs, plus a DSD Direct Access (DSD bypass) mode
  • Black and Silver are offered at the same $649

Worth noting

  • The page text gives no output level, SNR, size, weight or power figure
  • The page text states no Bluetooth version, only the codecs and LDAC's 24-bit/96kHz limit
  • The page text has no specification section, so its figures sit in prose and feature lines

Questions before you buy

Which chips does the D400 MK2 use?

An AKM AK4191 for digital processing and an AK4499EX for analog conversion. The page says separating the two stages gives a dedicated signal path; that is the page's own claim.

What inputs, outputs and sample rates does it list?

Inputs: USB, Optical, Coaxial, I2S, AES/EBU and Bluetooth. Outputs: XLR and RCA. PCM up to 32-bit/768kHz and native DSD up to DSD512, with MQA and MQA-CD decoding via USB, Optical and Coaxial, per the page.

Which Bluetooth codecs does it list?

LDAC (up to 24-bit/96kHz), aptX-HD, aptX, SBC and AAC, on a Qualcomm Bluetooth platform. The page text gives no Bluetooth version.

Where does HiFiGO ship from, and how long does it take?

From its warehouse in China, usually 1-3 business days after the order. The shipping policy gives 1-2 weeks to the US by Priority (6-10 days by Premium), both with duties and taxes prepaid, 2-3 weeks to Canada, 1-2 weeks to the UK and 10-15 days to Australia. Express couriers take 3-7 days, but the buyer pays any duties.

Can I send it back if I change my mind?

HiFiGO gives 7 days to report an item that arrives dead, damaged or wrong. Its policy also describes 30-day returns, but requests 7 to 30 days after delivery lose 30% of the MSRP plus shipping both ways and duties, and the FAQ on the same page says no refund or exchange after 7 days. Ask [email protected] before you open the box.

What warranty does HiFiGO give?

One year from the order date for parts and labor, for faults in build or materials (the policy names desktop DACs and amps, IEMs and dongles; cables and adapters get three months). HiFiGO chooses repair or replacement, the buyer pays the shipping, and a faulty item is serviced rather than refunded. Claims go to [email protected].

Sources & verification

What this review is based on and the day we last read it. Specs and claims from the maker are the maker’s own; the verdict and the rating are ours.

From the store

  • SMSL D400 MK2 AK4191+AK4499EX Desktop DAC product page: specs, options and price (the buy buttons go there)Specs, options and the listed priceRead October 28, 2026
  • HiFiGO shipping policyShips from China in 1-3 business days; US 1-2 weeks by Priority or 6-10 days by Premium, duties prepaid; Express buyers pay dutiesRead October 28, 2026
  • HiFiGO shipping and order tracking pageA second shipping text: Premium also for Canada and Australia, Canada free shipping from $99.99, lost-parcel rulesRead October 28, 2026
  • HiFiGO refund policy7-day dead-on-arrival cover; 30-day returns minus a 30% restocking fee; its FAQ says no refund after 7 daysRead October 28, 2026
  • HiFiGO warranty and refund policyWarranty by product class (1 year; cables and adapters 3 months); 30% fee for resealing an opened productRead October 28, 2026
  • HiFiGO terms of serviceOperator named only as HiFiGo; governed by the laws of China; contact [email protected]Read October 28, 2026

Independent

  • HiFiGO reviews on Trustpilot4.6 of 5 from 378 reviews (91% five-star, 5% one-star); the store has not invited reviews recentlyRead October 28, 2026

What we couldn’t verify

  • THD+N 0.00006%(-124dB) and 132dB dynamic range on XLR are the page's figures; the page text states no test frequency or load and gives no SNR, output level, size or weight.
  • The page says Hi-Res Audio Certified and full hardware MQA decoding; the page text gives no certificate details.
  • The page text gives no Bluetooth version for the Qualcomm platform, and the page's claims about a black background and soundstage are its own wording.
  • HiFiGO's policy pages contradict each other: 30-day returns with a 30% restocking fee in one place, no refund or exchange after 7 days in the FAQ.
  • HiFiGO's pages name no company, street address or phone number; the only contact given is [email protected].

Spotted an error or something out of date? Tell us and we’ll fix it and update the date.

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