xDuoo MT-602 Tube Class-A Headphone Amplifier

General Information

Product highlights
  • 2 x tube + transistor power
  • Class-A amplifier
  • Allows for tube swapping
  • Amp can be used as preamplifier
  • Power supply: DC12/1A
  • Output power: 1300mW (32Ω)
  • Frequency response: 10Hz-60kHz (+/-0.5dB)
  • Suitable headphone impedance: 16-600Ω
  • Gain: +15dB
  • Size: 4.7 x 3 x 1.5” (12 x 7.8 x 4cm)
  • Weight: 0.83lbs (0.38kg)
  • S/N: >115dB
  • THD+N: ≤0.01% (1kHz & 32Ω)

Latest reviews


A Neat Hybrid Tube Head-Amp
Pros: Open and clear sound
Tone texture
Cons: Unsuitable for sensitive In-Ears
MT-602 is not my first encounter with the Xduoo brand, which belongs to a TA-05 model. But just like the first time around I'm again having a hybrid tube headphone amplifier on the bench.

Build and Connectivity​

xDuoo MT-602’s design took a new turn compared to TA-05. First of all, it’s smaller, packed in a sand-blasted grey aluminum body. Except for the protruding tubes on the upper side, the red volume knob also makes sure the look feels fresh and modern. I’m usually not a fan of punchy bright colors but for some reason, it looks just right in this case, especially while it’s working and tubes are glowing.

On the back panel, we find two pairs of RCA outputs. One is reserved for line input while the other one is a variable pre-amp output. So yes, you can use this little thing as a small tube preamp too. It’s power with 12V DC and the laptop-sized brick is provided in the box. The front panel hosts a power switch, volume knob, and two headphones outputs, a smaller 3.5 mm one, and a bigger 6.3 mm. A little bit unexpectedly, there’s another auxiliary 3.5 mm input in the corner too. You’ll surely not hear me complain about connectivity here.

xDuoo MT-602 82.jpg


As already mentioned, xDuoo MT-602 is a hybrid amplifier. This means that tubes are used in a pre-amp stage while class A transistors provide power and grunt in the power-amp section. This is a scheme many products revert to trying to capture the soft and natural presentation of tubes, but without losing the power and control of a solid-state solution. That said, xDuoo claims a power of 1300 mW into 32 Ohms, with 15 dB gain, saying it’s suitable for headphones ranging from 16 to 600 Ohms. Looks promising on paper, but let’s see who it behaves in actual use.


So let’s get this out of the way first – does Xduoo MT-602 offers a warmer sound signature, as you might expect from a device with glowing orange tubes protruding from it? Yes, it does, but only to some extent, limited to a certain part of the frequency spectrum.

The Bass region is weighty and voluminous. When mass and boldness in lower registers are needed, this amp will provide. The bassline is not noticeably slow and sluggish, but it is also not the quickest one either. Pleasantly rounded is the description that comes to mind. Great thing is that texture was not sacrificed in the process. Vibrating bass strings sound like vibrating strings and not as a faceless sweet mass. This praise-worthy texture retrieval continues over the midrange section too. The upper midrange is actually the part responsible for that is open and textured sound. Because of it, listening to a saxophone, for example, is a joy. We get both bold instrument body and raspy airy texture on top of it. If anything, that whole upper midrange part is slightly more pronounced than I’d consider perfectly neutral. Luckily, it’s done in moderation and not overcooked to the point to become harsh or picky in any way. The highest region is again very clear and resolving. If you have hoped for a sweet and roll-off treble response, you’ll have to look elsewhere.

So tonally, I really liked this little hybrid amplifier, but what about other things? Dynamics are just fine, nothing to complain about, but also nothing to write home about. This is not a heavy-hitting kind of amplifier, it’s more the type of listener that appreciates smooth sailing. Sound-staging on the other hand is as good as it gets at this price point. There’s a decent sense of width, but not much depth and three-dimensionality though. Layering is quite capable with enough air around instruments.

xDuoo MT-602 80.jpg


This section will be short as xDuoo MT-602 possess enough power to drive almost anything that makes any sense pairing with budget amplifiers (yes, I’m talking to you guys that are using LCD-3 paired with fifteen times cheaper amps – stop doing that, it’s not appropriate sound quality wise first and foremost). Tonally, it’s open and bright, not too much so it shouldn’t be a problem for any headphones that are not overly bright (the ones with huge and wide hills in the upper midrange part of the frequency response).

If used with sensitive in-ears, MT-602 will produce noticeable static background noise. Also, the volume knob offers louse volume control resolution and things become too loud too quickly. With that, I’ll conclude that this is a big cans amplifier, not suitable for sensitive in-ears.


xDuoo TA-05 is also a hybrid tube/class A transistors amplifier but with clearly different tuning. Its bass is even more voluminous, mid-bass and midrange are warmer and with more bloom, while the highest frequencies are tamer and sweeter. It sounds as warm, bloomy, and sweet as someone could wish for if you’re after that kind of tuning. MT-602 on the other hand is more neutrally tuned, reveals more texture, and it’s brighter up top. Which one is better? Well, you’ll have to decide that one for yourself. I do prefer MT-602 but you might feel differently.

Topping L30 is a typical solid-state amplifier. It sounds clean, fast, and precise. Bass punch is decent, edges possess good energy. It sounds cleaner than MT-602. On the other hand, tone timbre and texture are not that pronounced. In that department, MT-602 has a slight lead to my ears. No matter how many times I went back and forth I couldn’t really decide on a clear winner here. It boils down to your taste and choice of music I suppose. If slow music with raspy vocals, saxophones, and other acoustic instruments is what you’re listening to most of the time, I’d give a slight edge to MT-602. If faster-paced tracks are your thing, you might appreciate a slightly punchier bass-line and more muscly presentation of the L30.

L30 is also dead silent even with sensitive in-ears so there’s that too.


To come clean, I expected yet another very warm and sweet-sounding amp, but xDuoo went in a different direction this time and I do believe it’ll pay off. I like this compact styling more than the old, vintage, and chunky one too. The price to performance ratio is great and if you don’t plan to use it with in-ears, and you find described voicing appealing, I can’t think of anything particular that should prevent you from seriously considering xDuoo MT-602 as your headphone driver.

. . .

My website with all the other reviews: https://iiwireviews.com/

Thanks to HiFiGo for sending it for the review: https://bit.ly/3eUJLCk

My video review:
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John Massaria
John Massaria
As I mention in my review below I find this amp amazing even with IEMs so long as you can control volume before the input as I have done with the computer volume OR with my Apache volume as a preamp to the MT602. I used all 16 IEMs including one iof the most sensitive Etymotic ER4Pro's without any issues what so ever this thing is a beast for $99.


Headphoneus Supremus
MT-602 - the Rest of the story...
Pros: well built, good power, pre-amp function works well
Cons: Single source with no switching between RCA and front 3.5 jack.

disclaimer: This review was originally posted to my blog on 2/12 but I decided to post it here after my images started showing up in other reviews of it. The MT-602 was provided for the purpose of this review and the tube rolling article by Xduoo Audio. I have no financial interest in Xduoo or any of its distributors, nor did I receive any compensation beyond the product itself for this review. If you have an interest in purchasing any of the Xduoo amplifiers I have recently written about, I suggest you check out Xduoo’s website directly as they now offer direct sales. You can also follow them on Facebook for more information.

Unboxing / Packaging:

The packaging of the MT-602 is a new style for Xduoo with a very western retail look to the box. The front has the line drawing of the amp while the reverse has company info and some suggested uses but does not have even basic specs. Lifting the top of the box reveals the manual and then a couple of blocks of heavy foam. The top most block serves to protect the pre-installed tubes, while the lower block protects the 601 itself. Beneath the unit and foam protection is a box containing the power supply cable. One thing worth noting, if you get the MT-601 and 602 both like I did, the power supplies look identical, have the same sized barrel connector so will physically interchange, but are not cross-compatible as the 602 uses a 12V power supply while the 601 uses a 24V supply. Close inspection of the box on the power supply does show that the only difference in the two (externally) is the voltage label. With these in black lettering on a black surface they do not immediately leap out so marking them in some easily seen way as you unbox them may be a wise plan to keep from having problems later.


The case is anodized aluminum in a matte gray with removable end plates and rear plate. To remove the internals for cleaning or repair, only the rear plate needs to be removed as the internals no not attach to either side plate. The top of the case is vented well around the tube and the side plates also have a pattern of vents showing the Xduoo X. A pair of 6AK5 type tubes are used and protrude only about .5 inches above the top surface. Inputs are a 3.5mm jack on the right front and a pair of RCA jacks on the rear. Outputs are a 6.3mm single ended output (a 6.3 to 3.5 adapter is provided) and a 3.5mm output on the front face, and a line out provided by a pair of RCA jacks on the rear of the unit. The line-out is volume controlled so the unit can be used to introduce some tube coloration and volume control to powered monitors. The 3.5s are clearly labeled as phone and aux in respectively so shouldn’t be easy to confuse. This is purely an amplifier so no usb, optical, or coax connectors are needed and the only other features not covered yet are a large red volume knob centered immediately in front of the tubes and a 12V DC input on the rear of the unit. Overall the unit stands a little over 1.5 inches tall (excluding the tube) , about 5 inches long and a little over 3 inches deep. The unit weighs slightly less than a lbs as well so is quite compact and comparable to the Schiit Magni or Modi in size and heft. The 602 is very slightly heavier than its 601 counterpart but for all practical purposes these two are identical in size and heft.


The MT-602 uses a pair of 6DJ8 tubes as the pre-amp followed by four D882M transistors that are used as a buffer stage. The 601 requires a large heatsink for its mosfet output, but here the four D882M transistors are mounted to the bottom of the board and don’t require the large heatsink used in the smaller sibling. Those interested in the D882M can find the datasheet here. Capacitors are either Elna Silmic or RubyCon branded throughout. The 602 also lists a built in mute circuit in the headphone output to prevent pops at power on. This either isnt present in the 601 or simply isn’t mentioned in the documentation. The 602 lists gain as +15dB so is slightly lower than the 601 in that measurement, but output power is much larger at 1300 mW into a 32Ω load compared to the 200mW of the 601. SNR is improved as well at 115dB compared to 100dB (601) while THD+N is not quite as good at <.1 at 1kHz with a 32Ω load. The 602 lists as suitable for use with headphones between 16 and 600Ω impedance and indeed was capable of powering just about anything thrown at it. The 6AK5 (6J1 Chinese designation or EF95 Euro designation) gives the user plenty of options to roll tubes in the 602 (an exercise I intend to do a bit later), as the 6AK5 has been in nearly constant production since the 1940s when it was introduced by Bell Labs and Western electric and used in early radar systems in fairly large numbers. It is not uncommon to find western electric examples with USN and an anchor on the packing designating those tubes accepted for military use during the war.


Normally the goal of an amp is to be gain on the wire and nothing else, but when we introduce a tube pre, it almost always has an impact on the signal in an audible way. So here we can talk about coloration as not only expected but welcomed. Those who want to avoid such coloration of the sound will likely opt for one of the many solid state amps that are available instead anyway. The MT-602 utilizes the 6AK5 tube family. This family also includes tubes labeled 5654, 6J1 (Chinese and Russian designation), CV4010 (British), EF95 (Euro), 403a/b (Western Electric) as well as 6AK5W and 5654W designations. The tube was originally used in radar sets and was used in a ton of military equipment over the years so they are commonly found as new old stock in military stockpiles. With nearly constant production from the early 1940s through today there are too many options to possibly account for all of them but they are somewhat less common on the market than 12au7 or 6DJ8 pre-amp tubes that are commonly used in this type device and may require a bit more digging to surface satisfactory pairs for use in the MT-602. I am working on a tube rolling article and will add the link here when completed but will suggest the early Sylvania JHS 6AK5 as a good all-around tube with better stage size and tonality than the stock offering. When used a pre-amp, I also found the Western 403b to be a good option as it complemented the Klipsch R-R1PM and Kanto TUK powered monitors I had available well.

Thoughts / Conclusion:

I had mixed emotions about the little brother in this series as I think it was of somewhat limited utility and should be thought of more as a pre-amp with a earphone output than a bonafide headphone amp. I have no such reservations here. The MT-602 offers good power and was able to handle all but the most demanding headphones without any issues. The pre-amp function worked very well using both powered monitors and in place of my standard pre-amp in my home system (which is asking a lot). If there is a drawback it is that as a pre-amp you only have a single RCA input on the rear and 3.5mm jack on front and no switching to handle which input is in use. This limits the 602 to being a single source pre-amp. Thankfully for most this will be part of a desktop stack and will probably be asked to handle output from a DAC or perhaps directly from a PC sound card. I think this is the role Xduoo envisioned the MT-602 being used in and it performs quite respectably when used as such. The 5654W miniature tube has a lot of options to tune the sound to the end-users liking although it does puzzle me that the 601 went with the more expensive and more commonly available 6DJ8 while the bigger brother went the minature route. I suspect this was in order to keep the cases on the two models the same size and dual 6DJ8s simply could not be fit in the same space. I’m not sure I would have chosen the case size as my over-riding variable here as going with a more common tube would open up even more options for buyers to tune and tweak the device.

For those interested, I have a tube rolling the MT-602 article posted to my blog. Rules here prevent posting a link so google MT-602 Tube Rolling.
The 602 uses 6Ak5 tubes so any of that family will work (5654, 6Ak5, Western Electric 403, etc). Disassembly is straight forward and quick. Can't speak to the Heresy as I don't have one in my inventory to test with.
Does the preamp sound warmer more tube like than the headphone out ?
not particularly no.

John Massaria

500+ Head-Fier
You Had me at $99, Class A, Red Knob, Sandblasted Chassis With Holes, Sound
Pros: Cutest thing on my desk top, great sound, works well with high impedance HPs HD600 and my lower Ohm headphones as well, pre outs are very useful (wish everyone did that-quiet pass through + transparent preamp), solid buy at this price (a real bargain for sound and coolness factor), powerful amp, can be used with sensitive IEMs but adjust gain for optimum volume control, makes music romantic and fun, details are clear while never being clinical, slightly warm to touch bit never hot, some bright headphones or sibilant headphones may just become your favorites now... and your favorite headphones may get used even more with this amp, a compliment to solid state amp owners -you may find yourself using this more, tube rolling goodness but not needed as stock sound is very satisfying
Cons: I am not a fan of power warts (but it works and it is quiet), wish it had XLR conn, not a transpartent detail monster like THX or Topping A90 nor should it be- this is smooth tube sound at a very reasonable price, only one input, can benefit from tube rubber damper rings if using speakers near by, at super low volume a very slight imbalance- but after turning volume up one little notch- it corrects itself


xDuoo MT-602 Tube Hybrid Headphone Amplifier

"You Had me at $99, Class A, Red Knob, Sandblasted Chassis With Holes, Sound"
The amp is beautifully adorable!!! Nicely finished, wonderful sound and with an output power of 1.3w... a real treat for $99. Hard not to fall in love with the romantic sound and price, looks etc you get me- I am loving this little amp! The class-A amplifier is very powerful - the MT-602 outputs up to 1300mW (32Ω) of power so high volume without distortion is easily achieved.


(Photo Credit XDuoo Facebook)
Sensitive easy to drive IEM's need very little volume- you may want to lower the volume on your pc to compensate with those IEM's. With HP's like the Sennheiser HD600 I achieve full volume bliss around 11:00-12:00 which is really awesome. The amp really shines with my GoldPlanar GL2000 and Kennerton GH50 JM Edition and of course truly a match made in heaven with HD600. High praise for here especially for price...

You Had me at $99, Class A, Red Knob, Sandblasted Chassis With Holes, and of course the sound. I feel like making all my friends try this and you will hear what I am talking about- what do you have to loose?

At $99 bucks I feel like I stole this -
I am captivated like the horses in this video:

(photo credit from Apos)
Nice feature all amps should have if including a preamp... like a Built-in mute circuit.... Anyone who’s ever plugged in their headphones before turning on their amplifier knows that many amplifiers make an ear-splitting “pop!” noise when turned on. Thanks to a built-in mute circuit, the MT-602 prevents this from happening, saving your ears and your patience. A very nice touch for sure.

Rolling tubes with the Sylania JHS 6AK5 may make the stage/depth a bit more focused but the stock tubes seemed very good and it really isn't a requirement to change or roll tubes here... but it is devilishly good fun to know that I can have the freedom to try different tubes latter in future.


I wish I knew about earlier... I wish I had this in my home sooner and well... I can whole heartily recommend with zero regrets. I strongly recommend this for anyone who may want to use tubes to enhance their musical pleasure- to add a dimension of sound you really can not expeience with solid state- really for me this MT602 is a must have for anyone with solid state amps.

For the price this is a no brainier purchase as a first, second or third teir in any system. I see myself buying more than one for my home (one for my bedroom, one for my desk top and a third for my office)... this was a 100% guilt free purchase where I got 10x the purchase price back in musical fun- and it's a good looking piece of kit on my desk... I got mine from APOS here - they shipped really quick and offer some crazy additions to why I use them when ever I make a purchase- this is a huge part why I trust them- they allow a 30 day return policy which honestly I think all dealers should do especially since we need to try before we buy these days- anyone not offering this as as dealer I would never use or recommend. Oppps! my bad... just checked their site and now they say it's a 45 day return.... my mistake! They clearly say they offer Free Shipping, Price Match Guarantee, Apos 2-Year Warranty and a 45-Day Return.


#MT-601 and #MT-602 are the same in design and configuration materials, only the tube are different. Sound performance also has its own characteristics. (Facebok XDuoo)



Product highlights
  • 2 x tube + transistor power
  • Class-A amplifier
  • Allows for tube swapping
  • Amp can be used as preamplifier
  • Power supply: DC12/1A
  • Output power: 1300mW (32Ω)
  • Frequency response: 10Hz-60kHz (+/-0.5dB)
  • Suitable headphone impedance: 16-600Ω
  • Gain: +15dB
  • Size: 4.7 x 3 x 1.5” (12 x 7.8 x 4cm)
  • Weight: 0.83lbs (0.38kg)
  • S/N: >115dB
  • THD+N: ≤0.01% (1kHz & 32Ω)

What’s included
  • xDuoo MT-602
  • AC cable
  • Adapter
  • 6.35 to 3.5 converter
  • User’s manual
  • Warranty card
Where to buy? APOS


From XDuoo Facebook page: https://www.facebook.com/xDuoousa/
So you know, I have 3 systems at my home- my speakers are Vandersteen 3a Signatures, Magnepan 3.6r and my desk top system which uses SEAS drivers in custom D'Appolito configuration.
I edit videos and film on location for professionals- I mix sound for a living occasionally after I film them in person- sometimes I am handed tracks that are terrible masters but am asked to make videos from them without re-mastering the sound. My IMDB page is https://www.imdb.com/name/nm8127846/
I am not a flake or hard of hearing at all-I get sound tested by my doctor each year or two. I grew up with sound engineers in the studio who were mixing albums at The Mix Palace and Platinum Sound Recording and The Power Station, Electric Lady Studios Studios in NY to name a few. When I like something I will review it such as the Kennerton headphones I reviewed on head-fi before. If I take the time to review something it has to be meaningful- it must have moved me and compelled me to do so- I do not get paid for any reviews.
I do this because I care to set the record straight on what I hear and how I felt about a particular piece of equipment. -JM


enjoy the music always everyone - a thing that unites us all as a world and planet .... bottom line if everyone owned a sweet sounding tube amp like this I really do believe war and poverty would end... what a happy world it could be for all... (maybe over the top but this thing sounds so darn good for the price I feel like I stole it)​


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Update: I did bought it
You were right it helped smooth out the mt beyer peak and a good alternative from my solid-state amp kudos for the review
John Massaria
John Massaria
And that cute thing on your desk top
I wonder how this compares with Vali 2+



Headphoneus Supremus
Just ordered one and since I have a Little Dot MKIII I have lots of tubes to roll...


Headphoneus Supremus
Took a look and I already have matched pairs of Russian 6J1, Yugoslavian 6HM5, 67' Sylvania 5654 & GE 5654 plus 2 pairs of the Tung-Sol 6AK5W! Let the rolling begin...well I'll need the amp first supposed to be here in a month!
Slow boat from China.


100+ Head-Fier
Took a look and I already have matched pairs of Russian 6J1, Yugoslavian 6HM5, 67' Sylvania 5654 & GE 5654 plus 2 pairs of the Tung-Sol 6AK5W! Let the rolling begin...well I'll need the amp first supposed to be here in a month!
Slow boat from China.
The one reason why I'm hesitating on this vs 601 version is because of lack of high end tubes for the 602. The 601 has a much more common tube socket and therefore has much more tubes to pick from and if I'm only using this as a preamp then I'm wondering if I'm better off going with the 601 however the specs such as distortion and dynamic range seem to be much better on the 602 So I am kind of stuck between a better tube but a wor se design around it or a worst tube at least a less common tube but a much better surrounding circuitry. I am planning on buying a linear power supply and the 24 volt of the 602 is going to be much more expensive than the 12 volt of the 601 as well. So many choices let me know how yours goes or if you have any advice.


Headphoneus Supremus
I think you will have some nice tube options with the 602, that's one of the reasons I went with it.
Tung-Sol 6AK5W and Yugoslavian tall bottle 6HM5 is enough for me to go with it and the increase in power from the 601 sealed the deal! Actually I never even considered the 601 but did briefly consider the 604 but didn't want to deal with quads as I only have matched pairs.
Also the 602 uses a 12V PS.


Headphoneus Supremus
Can someone tell me the power supply barrel connection diameter and pin out, I'm thinking of getting a better power supply for this unit. Also anyone have any opinion on the stock PS? I know on my Loxjie P20 upgrading the supply made audible improvements. :thinking: