Topping NX7 Portable Headphone Amplifier

[ducnsh]

Are there alternatives to this today? How hard or easy is it to replace the battery? Does it require soldering or is it just a matter of clipping new ones in? Cheers.

I have the same questions; I am curious about the battery replacement process

 

[vilders]

Can someone tell me how to properly connect this amplifier to the player. What volume level can or should be set at the player's output?
So as not to damage anything in the amplifier.

 

[BobSmith8901]

Can someone tell me how to properly connect this amplifier to the player. What volume level can or should be set at the player's output?
So as not to damage anything in the amplifier.

If you mean the basic connection from DAP or smartphone to the amp, that would be 3.5mm line out or headphone out to the NX-7 line in (which is 3.5mm).

My DAPs have line out capability and I haven't had any issues with overdriving the NX-7 using their respective 3.5mm jacks in line out mode. Most of them also have adjustable gain on line out.

For Smartphone connection I use the phone's headphone out to connect to the NX-7 and I just start with, say, 50% volume, and see how it is. Most phones aren't going to have much voltage out of their headphone jacks so there's little chance of frying the NX-7. After the initial check I think I usually end up putting them at around 90% volume to give the amp some half-way decent juice. Of course always keep the NX-7 volume minimized at first if you're wearing headphones.

 

[jjss]

Can someone tell me how to properly connect this amplifier to the player. What volume level can or should be set at the player's output?
So as not to damage anything in the amplifier.

This amp is designed with better performance when its connected to a source (DAP / DAC) that has line out, some one in ASR forum did mention that the amp requires 1.4Vrms to allow full output voltage in high gain setting. I use A&K DAP that has line out and selectable output voltage so that matching the 2 is easy as the DAP has quite a few output voltage to choose from. But I also have used the Mojo OG line out (which has a 3V line output) to drive the NX7 and technically there is no problem at all and the only downside is that the usable volume range on the amp becomes fairly limited rendering the tuning for the volume sweet spot difficult. But then again there is a way to get around this and its by using either a impedance adapter (like those from Fiio) or the iEMatch from iFi to bridge between the Mojo line out and the amp's line in, in this way you could recover much of the dynamics and transparency in the music that otherwise would gave been "compressed" due to limited loudness range. Hope this helps ..

 

[vilders]

So it's better to use the DAP/DAC's line output. Great, thanks everyone for the answers.