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xDuoo MT-04 Hybrid Tube Headphone Amp Review

A hybrid tube and transistor headphone amplifier from xDuoo with two 6H3 tubes in the preamp stage, 6.35mm and 4.4mm outputs, balanced input and output and a rating of 2200mW, listed at $169.99.

4.0Editorial rating: 4.0 out of 5Editorial rating · research-basedUpdated November 11, 2026
$169.99Price checked November 12, 2026Pre-order only at Linsoul at our last check (November 12, 2026)
Check price at Linsoul

Our verdict

A hybrid tube and transistor headphone amplifier for someone who wants two 6H3 tubes, 6.35mm and 4.4mm outputs and a balanced input and output at $169.99. Look elsewhere if you need an output power given with a load or a listed input connector type, since the listing text gives neither. The main caveat is that the sound descriptions are the maker's claims and the 2200mW rating names no load.

Best for
Someone who wants a tube preamp and transistor power stage in one headphone amplifier with 6.35mm and 4.4mm outputs.
Skip if
You need a listed DAC chip or an output power given at a stated load.

A tube preamp stage and a transistor power stage share the xDuoo MT-04, which the page describes as a hybrid design: two 6H3 vacuum tubes handle preamplification and a Class A transistor circuit handles the output. It is rated at 2200mW with no load named and lists balanced input and output, 6.35mm and 4.4mm headphone outputs and an external gain switch. The price is $169.99 for a single orderable option.

Options and pricing

There is a single orderable option at $169.99, and the page shows $199.99 crossed out beside the price, which is the store's own comparison and not something we checked. The two headphone jacks, 6.35mm and 4.4mm, are both on the one unit, so there is no plug option to pick, and the gain is set with an external switch. The listing text gives no weight or dimensions.

How it compares

The xDuoo DA-100 is $143.65 and its listing mentions an ES9018K2M chip, the SMSL DS20 is $189.99 and mentions CS43131, and the Shanling EH1 is $199 and mentions CS43198 and SGM8262. The MT-04 is $169.99 and its page names no DAC chip, only tubes and a Class A transistor stage.

Shipping

  • Methods and costs. The store's shipping page offers Standard Shipping (4PX, Yanwen or Yun Express), free for most countries, and Express Shipping (DHL Express, FedEx or SF Express) at 15-50 USD depending on the country, free for orders over 270 USD in most countries (checked 2026-11-11).
  • Large items. The page says headphones and desktop DAC/AMPs count as large items, for which Express is free only for orders over $499.99.
  • Delivery times. It says an in-stock order ships within 3 working days, Standard takes about 2 weeks after shipping out (up to 1-3 months for some countries, and the store makes no refund for that transit time) and Express takes about 3-7 days. Festive seasons and other circumstances can change the timing.
  • Taxes and fees. The buyer pays any customs, import or processing fees. The page says Standard via YunExpress is tax-inclusive for some countries, that remote areas can carry extra Express charges, and that a parcel refused or left uncollected over taxes is deducted two-way freight and may be destroyed with no refund.
  • Where it ships. The page says the store can generally ship to most countries by Express and many by Standard, and to confirm Standard with the team for your country. It cannot ship to PO boxes or APO/FPO addresses and can only use Express to Hawaii. It does not name the US, Canada, the UK, Australia or New Zealand, so confirm before you pay.
  • Lost parcels. If a parcel has been in transit for at least 3 months, the page offers a one-time reshipment or a full refund for orders under $50 and a 50% refund for orders above $50.

Returns and warranty

  • Returns. The return page allows returning any non-customized product that is still factory sealed within 30 days of receiving it, with the buyer paying the shipping. Email [email protected] within that period; the store asks for the return to be shipped within 5 working days of the RMA instructions and in most cases processes a refund within 5 business days of inspecting it (checked 2026-11-11).
  • Opened items. A product opened within the first 7 days after delivery can be returned for the price minus a restocking fee of 35% of its retail value, including when it still works properly.
  • Refund or credit. The buyer can choose a refund to the original payment method (PayPal or card) or store credit; with no answer within 48 hours of confirmation the default is store credit, which can also be prioritized during promotions, final-sale events and for items 40% or more off retail.
  • Not returnable. Customized products, including faceplate designs, are non-refundable, and the page says the same applies to carry cases, cables, ear tips and other accessories, "due to hygiene purposes". If one item in a package is defective, incorrect or missing, the refund or replacement covers only that item.
  • Warranty. The page gives a 1-year warranty on products, excluding carry cases, ear tips and other accessories, and 3 months on cables and adapters, from the date of purchase. It covers factory defects that affect proper function, not damage from human error, negligence, accidents, dismantling, water, abuse or modification (checked 2026-11-11).
  • Not covered or limited. It does not apply to items bought elsewhere (AliExpress, Amazon, local dealers and the like), prize or giveaway items, normal wear or colour change, commercial use, or items that were stolen or went missing. Coverage is limited for products 40% or more off retail, for review units and for items repaired or modified by anyone Linsoul has not authorized.
  • Claims. Email [email protected] with the order number, the issue and photos and videos of the fault. The store may ask for the unit back for a replacement. It covers shipping for some defects reported within 7 days of delivery if the fault can be shown on video or photo; after 7 days the buyer ships it back. For wrong or missing items an unboxing video of the whole sealed parcel is required.

Before you buy

Linsoul says it was founded in 2016 by the Crazy HiFi team to bring Chinese HiFi makers closer to listeners worldwide, and that it now sells other makers' products alongside four brands of its own, THIEAUDIO, Kiwi Ears, ZiiGaat and Tripowin (checked 2026-11-11).

We have not read any independent review of this product or of the store. Ratings and owner reviews shown on the store's own pages are the store's and were not verified.

What we liked

  • The page lists a rated output power (2200mW), the tube type (6H3) and the Class A transistor stage
  • Both 6.35mm and 4.4mm headphone outputs are listed, with balanced input and output
  • An external gain adjustment switch and an external ground terminal are listed
  • The page names ELNA coupling capacitors and Rubycon filter capacitors
  • A relay protection circuit with a 30-second power-on delay is described

Worth noting

  • The 2200mW rating comes with no load or impedance, so it cannot be compared with figures that give one
  • The listing text gives no input connector type, weight or dimensions
  • The sound descriptions on the page are the maker's words and cannot be checked from the listing
  • The page gives no THD, SNR or frequency response figures

Questions before you buy

What tubes and output stage does the MT-04 list?

The page lists two 6H3 vacuum tubes for preamplification and a transistor-based Class A current expansion circuit for the power stage, rated at 2200mW with no load named.

Which outputs does it have?

The page lists 6.35mm and 4.4mm headphone outputs and describes balanced input and balanced output. It says no adapter is required for mainstream headphone plugs.

Does it have a gain control?

The page lists an external gain adjustment switch for in-ear and over-ear headphones of various impedance. It does not give the gain steps or values.

Can I return it if I change my mind?

The return page allows returning a non-customized product that is still factory sealed within 30 days of receiving it, with the buyer paying shipping. An opened product returned within 7 days carries a 35% restocking fee. Refunds go to the original payment method or to store credit, which is the default if you do not choose.

How long does shipping take?

The shipping page says in-stock orders ship within 3 working days. Standard Shipping takes about 2 weeks after shipping out, up to 1-3 months for some countries, and Express takes about 3-7 days. Standard is free for most countries; Express costs 15-50 USD and is free over 270 USD (over $499.99 for large items such as headphones and desktop DAC/AMPs).

Does Linsoul ship to the US, Canada, the UK, Australia and New Zealand?

The page says Linsoul can generally ship to most countries by Express and many by Standard, and to ask the team about Standard for your country. It names no restriction for the US, Canada, the UK, Australia or New Zealand, but it does not list them either, and it can only use Express to Hawaii.

What warranty does it have?

The page gives a 1-year warranty on products from the purchase date for factory defects, not for human error, accidents or modification. Coverage is limited for items 40% or more off retail and for review units, and it does not apply to items bought from other sellers.

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

  • xDuoo MT-04 product page: specs, options and price (the buy buttons go there)Specs, options and the listed priceRead November 11, 2026
  • Linsoul shipping pageStandard and Express shipping, costs and times, import taxes, lost parcels, couriers, trackingRead November 11, 2026
  • Linsoul return policy and warranty page30-day returns of sealed items, 35% restocking fee on opened ones, 1-year and 3-month warranties, exclusions, how to claimRead November 11, 2026
  • Linsoul support FAQThe same shipping, return and warranty rules in question form, plus order changes and cancellationsRead November 11, 2026
  • About LinsoulFounded in 2016 by the Crazy HiFi team; names its own brands; the awards listed there are the store's own accountRead November 11, 2026

What we couldn’t verify

  • The page's descriptions of warm, mellow vocals, smooth treble, tight bass and high resolution are the maker's claims and were not checked here.
  • Per the page, the output power is rated at 2200mW, with no load or impedance named, and no THD, SNR or frequency response figures are listed.
  • The listing text gives no input connector type, weight or dimensions, and the page says nothing about gain steps.
  • We have not read an independent review of this product or the store, and the store's own ratings were not verified. We read the store's catalog description only: a specification table or image shown just on the live page was not read.
  • The shipping page names no US, Canada, UK, Australia or New Zealand times or fees: its figures are general and we could not confirm them for these countries.

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

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