This is my first review, but I have such a conflicted relationship with this device, I wanted to put it down in words! As this review focusses on use as an amp, I'm not going to use the typical "highs miss lower structure. If you read this you'll see why.
Firstly, this unit was give free to me by hifiheadphones.co.uk in the UK, who had a bit of a service failure with an order of mine, and so (following a joking request from me to customer service) delivered this as a "present" (along with the HD600s I had ordered) . I am in no way affiliated with either Topping or hifiheapdhones (save as a customer) and this review represents my honest opinion. I have received no inducement to write this review.
Kit: I tested the NX2 as a USB DAC/AMP from both a windows laptop, a Samsung Note 8 and Galaxy S8. I have used it with Shure SE215s, 425s, KEF M500s and Sennheiser HD600s. Here's a nice picture... it's tiny!
DAC: after about 10 minutes of using as both a DAC and AMP, I stopped and almost chucked this unit away. Whilst it delivered volume, the sound (using as a dac) was not good. There was a lack of detail, as if the music was far away and veiled, with a muddy/flabby feeling. Honestly, I nearly wrote the unit off there and then. I slung it in my bag and didn’t think anything more of it. I wont even bother with test tracks, highs-mids-lows etc. Trust me, the answer in each column is "awful, just awful".
Redemption: A few weeks passed, and I was working away from my normal office, listening to my music on my 425s direct from my note 8. I have always thought the 425s do better with a little amplification (and my dream pairing had always been my dragonfly until I lost it). I suddenly remembered the NX2 and plugged it in as an amplifier using the 3.5mm male to male it came with (crappy, swapped out for a fiio one i had lying around). And I was seriously pleased with the results. I can't profess to have volume matched, but sticking the NX2 between the phone and the 425s gave them that much wider, fuller feeling sound the 425s reproduce under amplification. Where I really notice it is in soundstage (width) and bass response. Without amplification I think the 425s can be a little shy of bass, but with amplification (including with the NX2) that tight, clean bass they deliver has an extra level of oomph I really enjoy. The first time I ever experienced this degree of clarity from my 425s was after having first bought my dragonfly 1.2 which retailed at about 5 times the cost of this little NX2. I genuinely cannot fault its incredible value for money.
The other headphones I have in the office are the KEF M500s. These get plenty loud from a phone, and so I wasn’t expecting much to change. And it didn’t really – the NX2 drives them louder and there may be a feeling of wider soundstage, but it is negligible. What it does do though, is add clarity. Don’t get me wrong, the M500s don’t have a muffle issue, but I do notice from direct outputs from both the S8 and Note 8, a muffle that amplification seems to clear.
When I got home that night, I also gave my HD600s a bash with it – and you know it does a good job! The phone itself doesn’t drive my HD600s to a nice listening volume for me, but the tiny little NX2 comfortably provided all the noise I needed!
So, a £30 box which delivers ridiculous amplification for such a tiny, compact, convenient unit (crap DAC or no) is a sure fire 5 stars, A++ right? Not quite…
Unfortunately, the NX2 suffers from 2 issues:
Firstly, the battery charging port is USB mini. It is literally the only USB mini device in my house, and I cannot understand why Topping would not simply use the ubiquitous USB micro standard.
Secondly, this unit suffers from massive and unforgivable electronic interference. Given it is marketed as a mobile device, any time it is near a phone, you have (with no music playing) the tell-tale clicking and buzzing of mobile phone interference. Add music playback to the mix, and the ripping/tearing/clicking/popping is unlistenable. This can be noticed when stationary in an area of good signal but makes the device totally unusable on train journeys where the phone is regularly trying to contact the network. This flaw makes the Topping NX2 practically unusable whilst travelling which is (considering how convenient and effective it otherwise is) a real shame.
Conclusions
I love and hate this Topping NX2. As a DAC it is terrible. As a straight amp, its size, convenience and the simply fact it does a great job of what it is there for, give a lot to recommend it for. And I love it for making my 425s sparkle. I could even overlook the nonsensical use of the usb-mini format. But I cannot forgive the RF interference – it makes it, when using a phone as a source (which, lets face it, the vast majority of us will be doing) totally unusable.
Firstly, this unit was give free to me by hifiheadphones.co.uk in the UK, who had a bit of a service failure with an order of mine, and so (following a joking request from me to customer service) delivered this as a "present" (along with the HD600s I had ordered) . I am in no way affiliated with either Topping or hifiheapdhones (save as a customer) and this review represents my honest opinion. I have received no inducement to write this review.
Kit: I tested the NX2 as a USB DAC/AMP from both a windows laptop, a Samsung Note 8 and Galaxy S8. I have used it with Shure SE215s, 425s, KEF M500s and Sennheiser HD600s. Here's a nice picture... it's tiny!
DAC: after about 10 minutes of using as both a DAC and AMP, I stopped and almost chucked this unit away. Whilst it delivered volume, the sound (using as a dac) was not good. There was a lack of detail, as if the music was far away and veiled, with a muddy/flabby feeling. Honestly, I nearly wrote the unit off there and then. I slung it in my bag and didn’t think anything more of it. I wont even bother with test tracks, highs-mids-lows etc. Trust me, the answer in each column is "awful, just awful".
Redemption: A few weeks passed, and I was working away from my normal office, listening to my music on my 425s direct from my note 8. I have always thought the 425s do better with a little amplification (and my dream pairing had always been my dragonfly until I lost it). I suddenly remembered the NX2 and plugged it in as an amplifier using the 3.5mm male to male it came with (crappy, swapped out for a fiio one i had lying around). And I was seriously pleased with the results. I can't profess to have volume matched, but sticking the NX2 between the phone and the 425s gave them that much wider, fuller feeling sound the 425s reproduce under amplification. Where I really notice it is in soundstage (width) and bass response. Without amplification I think the 425s can be a little shy of bass, but with amplification (including with the NX2) that tight, clean bass they deliver has an extra level of oomph I really enjoy. The first time I ever experienced this degree of clarity from my 425s was after having first bought my dragonfly 1.2 which retailed at about 5 times the cost of this little NX2. I genuinely cannot fault its incredible value for money.
The other headphones I have in the office are the KEF M500s. These get plenty loud from a phone, and so I wasn’t expecting much to change. And it didn’t really – the NX2 drives them louder and there may be a feeling of wider soundstage, but it is negligible. What it does do though, is add clarity. Don’t get me wrong, the M500s don’t have a muffle issue, but I do notice from direct outputs from both the S8 and Note 8, a muffle that amplification seems to clear.
When I got home that night, I also gave my HD600s a bash with it – and you know it does a good job! The phone itself doesn’t drive my HD600s to a nice listening volume for me, but the tiny little NX2 comfortably provided all the noise I needed!
So, a £30 box which delivers ridiculous amplification for such a tiny, compact, convenient unit (crap DAC or no) is a sure fire 5 stars, A++ right? Not quite…
Unfortunately, the NX2 suffers from 2 issues:
Firstly, the battery charging port is USB mini. It is literally the only USB mini device in my house, and I cannot understand why Topping would not simply use the ubiquitous USB micro standard.
Secondly, this unit suffers from massive and unforgivable electronic interference. Given it is marketed as a mobile device, any time it is near a phone, you have (with no music playing) the tell-tale clicking and buzzing of mobile phone interference. Add music playback to the mix, and the ripping/tearing/clicking/popping is unlistenable. This can be noticed when stationary in an area of good signal but makes the device totally unusable on train journeys where the phone is regularly trying to contact the network. This flaw makes the Topping NX2 practically unusable whilst travelling which is (considering how convenient and effective it otherwise is) a real shame.
Conclusions
I love and hate this Topping NX2. As a DAC it is terrible. As a straight amp, its size, convenience and the simply fact it does a great job of what it is there for, give a lot to recommend it for. And I love it for making my 425s sparkle. I could even overlook the nonsensical use of the usb-mini format. But I cannot forgive the RF interference – it makes it, when using a phone as a source (which, lets face it, the vast majority of us will be doing) totally unusable.
which will cost me an arm and leg.