XDUOO MH-02 USB-DAC&TUBE-Kopfhörerverstärker unterstützt bis zu PCM32bit/384 kHz und DSD256

IntroductionI've been an avid headphone user for many years now - pretty much since the introduction of the first Sony Stowaway (Walkman) in the very early eighties. I've worked my way through countless sets of headphones and players from cassette, through Mini Disc, Discmans' and MP3 players - finally arriving at my current portable player which doesn't even have an headphone socket - the Samsung Galaxy Note 20 Ultra. Fitted with a 512gb memory card and using either Bluetooth headphones or an external amplifier, this has become my player of choice for music.I have two external dac/amps - the Fiio BTR7 and most recently the Xduoo Tube Amp. Both of these are excellent and they get used on a regular basis. My most recent purchase is the Xduoo which has replaced a recently returned Fiio K11 (which I have to say was also truly excellent). I chose the Xduoo because I really like it's smooth sound. Now don’t get me wrong, when I say smooth, I don’t mean that it’s soft and overly mellow - far from it. this amp really reproduces the detail in your music - and it goes loud.I’ve paired the amp with my recently purchased Hifiman Deva Pro’s and I’m using a 4.4mm balanced cable (perhaps completely unnecessary with this amp as although it offers the relevant socket, it’s not a true balanced output. However I do use these headphones with the excellent Fiio BTR7 portable bluetooth amp as well so all is good.When I first purchased the Deva Pro’s I felt that, although they are a good set of headphones, I felt that they were not ideal when listening to rock or electronic/trance type music. However, with the inclusion of the Xduoo MH02 all that has changed and I now think that they are an ideal all-rounder. The Xduoo can certainly push a lot of power into these headphones - even on the low-gain setting.I have only so far used the MH-02 as a DAC/Amp rather than a conventional headphone amp or pre-amp. The DAC sounds perfectly fine as far as I’m concerned and I personally feel that there’s no point in using an alternative DAC. I’m aware that some people have had great success in pairing the Fiio K11 R2R to the Duoo - I personally can’t help thinking that the additional expense that this involves is simply not worth the effort. I have noticed that the amp is sensitive to RF noise if I have my phone too close but this isn’t a problem once the phone is more than a foot away from the amp.The MH-02 does run warm but not hot. Even the tubes tend to only get slightly warm rather than too hot to touch. There’s some significant channel imbalance at the lowest volume setting but this only happens at super low volume levels - again, not something that would bother me. I love the relaxed presentation this amp brings to music. There’s no listening fatigue whatsoever - no matter what genre of music I’m listening to. I think it’s fair to say that this remarkable little amp has transformed my Hifiman Deva Pro’s in just the right way.I recently purchased a couple of inexpensive GE tubes based on Head-Fi recommendations. Whilst they did alter the sound characteristics somewhat, I honestly preferred the sound from the original tubes. For me, the GE’s produced perhaps a little more detail and tightened up the bass a little, it also sounded a little thinner. The original tubes have this wonderful ‘bloom’ to the sound. In all fairness though I haven’t given the tubes a chance to burn in properly yet - I might give them another go (although I’m a little worried about the additional wear and tear from continually swapping out the tubes so I might just settle with the originals which I do like the sound of anyway).ConclusionI really love this amp. It looks good. It sounds great. It goes more than loud enough to meet my needs with all the headphones in my collection and doesn’t cost a lot of money. I would have liked to see a genuine balanced output on the 4.4mm socket but whether it would make a significant difference is actually hard to say. I went balanced with my wired headphones because the Fiio BTR7 has significantly increased output when used balanced - with the Xduoo though it’s not really an issue because the amp is more than powerful enough through single-ended output. All in all, I highly recommend this remarkable little tube DAC/Amp.