NX4 is imagined to be a great DAC and headphone amp in a compact body. It’s joined with a battery which makes it portable too.
BUILD AND FUNCTIONALITY
NX4 comes with a built-in battery so you can use it on a move without draining your smartphone or laptop battery. It’s small but pleasantly heavy and sturdy looking. When fully charged it can give you 6 to 7 hours of music playing. That goes to more than 20 hours if you use it only as a headphone amplifier. That said, the DAC part is really good. It’s probably much better than the one in your phone or laptop, so not using it would be a waste of NX4s talents.
The headphone amp has a high gain mode for power-hungry headphones and bass gain mode for bass-heads or owners of bass-lacking headphones. Both of these functions are working very nicely. One thing I didn’t like is that when the battery is low on energy, LED will turn red just a few minutes before the whole device turns down. It would be much better if it were to turn red one hour in advance for example. That way you would have a warning with some meaningful usage time left in it. This way, if you go far a walk, run, etc. and it turns red, that’s it, you’re just counting down the minutes until it shutdowns on you. So be sure to keep it regularly charged. But if you use it mainly at home as I do, then it’s not a problem.
So how does it sound? Let’s start with Line-out for which I’m glad to say it sounds really good. Sound is clear and energetic, while soundstage is big and wide. I can’t notice any added brightness or harshness. Everything is just in the right place and it’s a real delight to listen. I compared it to desktop-oriented Topping D30 and I didn’t notice any meaningful difference. If I listened very closely, NX4 could sometimes sound cleaner in the high frequencies and give some really fine details that are just not as clear on D30. In most songs and music genres this is difficult to spot, but in some cases, NX4 can organize things just a bit better. The difference is really subtle and you can easily miss it in a system that is not that revealing. But if you really want to nitpick to that last tiny detail, NX4 is a better sounding device by a hair.
Let’s talk about headphone-amp. I tried several in-ears, as well as bigger AKG K92 with it. I can tell you it sounded great with every-one of them. There are lots of details and power. NX4 can provide deep and tight bass, full-bodied vocals and mids in general.
Comparing it with Sabaj Da3 which is a great little device on its own, NX4 proved to be a bit cleaner in general. It offered better layering and depth to the sound. You can barely notice that with small In-ears but with demanding headphones Da3 can exhibit a slight loss of bass control and some high-frequency harshness, especially if you crank the volume up. NX4 on the other hand still sounds full and powerful and keeps perfect composure even at these high levels. That dedicated headphone amp really means a lot when more power is needed. I actually never had to use it because none of the tested headphones really needed it. But I tried it anyway and noticed just a slight change in the sound, it was a bit more in your face and a bit less spacious. All other qualities remained the same. Even though most of you will probably never going to need high gain mode, it feels safe having it just in case.
In conclusion, except that a small complaint about that battery LED warning showing too late, I really liked Topping NX4. As a DAC, it matched and even slightly surpassed the sound quality of D30. It also comes with a really good headphone amp that can drive most headphones without a problem. It’s portable too. NX4 is a stellar multipurpose device with a great set of skills. If you find yourself in need of these skills – it’s an easy recommendation.