Miniwatt is based in HongKong and for the past 5 years have been creating miniature high quality products such as Miniwatt_N4_1the S1 tube amplifier and n3 headphone amp. Most recently they have created the n4, a high current headphone amplifier, which can also be used as a USB to SPDIF converter and USB Dac featuring an Asynchronous USB input in order to control jitter and error correction. The inbuilt Dac reaches resolution levels of 32bit 192khz.

Overview of the Presentation


The treble on the n4 appears to be slightly rolled off (or damped a little) but it is still very detailed, with a smooth nature to its presentation – attractive nevertheless and very easy to listen to.


Midrange frequencies were detailed, smooth and on the warm side of neutral making them extremely musical. This headphone amplifier would seem to have the qualities of a good Class A amplifier.


The rich upper bass is well extended and informative whilst being detailed and possessing terrific rhythm which really adds to the musicality of this amp.


The soundstage using this diminutive headphone amplifier is convincingly wide with good centre focus and great layering.


Hooking the Miniwatt up to my Mac was a breeze. It has no external power supply and takes its required 5v from the USB socket.  I plugged in my Wireworld Ultraviolet USB cable to each device, then selected the ‘USB Speakers’ option from the settings dashboard, loaded up Amarra 2.5 and selected the bit-rate from the ‘Midi Audio Setup’. Job done!

Connecting the n4 to a Windows based machine is simple also – simply double click the volume icon on the task bar, select the device as ‘default’, right click the device, choose properties and select the bit-rate.

So with iTunes integrated into Amarra as the library (that’s another story for another day) I began to flick through some music. Miniwatt_N4_2

The Sound

I started by listening to Ed Sheeran. First impression straight off was how smooth the midrange was, coupled with a delicate treble and informative bottom end. Midrange was more of a star though on my Beyer DT990’s which gave Sheeran’s vocal great body. There was a wonderfully quiet background.

I detected a slight hiss in between tracks but nothing major and certainly nothing that distracted from the listening experience.

I immediately wanted to try something at the other end of the musical spectrum and picked out a copy of ‘Trance Nation 2009’… a great year for it!

Now we’re talking, from delicate vocals and a softly, softly approach to some hard hitting beats and some manufactured well mixed notes. There was a terrific crispness to high end notes and good detail – even though they lacked sparkle they sounded fun and definitely weren’t edgy. Bass was taught and punchy.

There was a great musical appeal to the amp early on, a bit more top end zing and extension would be nice but the way it was presenting sounds was really very pleasing.

Onwards for a taste of a variety of musical styles in between the above two and so I made up a playlist of WAV files from my NAS drive.

First up was Christina Aguilera featuring Alicia Keys ‘Impossible’. The very powerful vocal from Christina is exposed by any bright, uncontrolled system. The Miniwatt played back the track through my Beyers admirably, no screeching or forwardness to report here and Alicia’s piano was delicate and well pronounced.

Micheal Buble’s ‘All Of Me’ is a hugely dynamic song and the n4 displayed all these dynamics in a way which I am used to hearing them on my main system, very impressive indeed. The n4 has a 126db dynamic range and it really knows how to work it.

Next up was ‘Keith Don’t Go’ by Nils Lofgren, the guitar solo two thirds of the way through the track has awesome vibrancy and decay (I’m waiting for it as I write, so lets see what happens…).

A rich over-tone with a smooth top end it decayed pretty well. There just isn’t that real top end sparkle and airiness due to the rich texture of the Miniwatt. I think this is definitely due to the high current amp and voicing of the inbuilt Dac in order to combat edgy digital recordings. ‘Black Books’ another fantastic track with a similar guitar solo confirmed my thoughts.

Following On from Nils was Norah Jones. I played various tracks from the albums ‘Feels Like Home’ and ‘Come away With Me’. I felt that due to Norah’s rich tones and a lot of bass guitar in many of the tracks the Miniwatt n4 this time over-shadowed the vocals a little with its warm upper-bass lower-mid tones. The lack of the top end sparkle here couldn’t balance the tracks out, where as my Creek OBH21SE makes Norah sound like an angel.

Jack Johnsons ‘Broken’ is a fantastically musical track with great vocals and strong leanings to each side of the soundstage with numerous instruments. All I felt were well placed correctly and the thick bass notes were great. This track also displays ambient acoustic solos without bass and they sounded terrific in a well placed soundstage. No smearing between layers was apparent; there is just that thick Miniwatt characteristic which pleasantly adds body to almost everything.

Iyaz ‘Breath’ has a fairly hefty upper bass to begin with so I was curious if the n4s ‘thick and fruity’ flavour would make this a little over powering. Well it didn’t, the Miniwatt injected good detail over this frequency with texture to it and the lower mids. I didn’t think it would be an ideal track for its presentation but I was pleasantly surprised. Once again sound staging was nice and layered.

Def Leopards ‘Rocket’ sounded great with no edginess, which I don’t like much when reproducing rock music at home. I know people who listen to 90% rock music and love the edginess and a bit of brightness to their system. If I listen to rock it has to be a bit toned down, especially screaming through headphones and the Miniwatt sounded exactly the way I enjoy what little rock I listen too.  I listened to a good handful of the ‘Hysteria’ album after testing this track and it was all good.

SPDIF Converter

The Miniwatt has a little trick up its sleeve in that it can be used as an SPDIF converter, allowing Dacs without the option of an in-built USB socket to utilise the digital signal from their PC or Mac. This option is a wonderful addition and on linking it to my own Dac with my Valhalla coaxial RCA cable I was pleasantly surprised to hear a sound I was more familiar with in my main system. I’d rather us this option than the mini toslink output from the Mac which I have never been a huge fan of.

It had a vivid, vibrant and clear sound. Deep bass and the gorgeous mids that I get from my system. I prefered the SPDIF conversion on the Miniwatt to previous items I have used including the Teredak and M2Tech Hiface.

Using as a USB DAC

Fed through my system via a pair of Oriton Orange Symphony Interconnects, still using the Wireworld USB into the headphone amplifier I played many of the of tracks I played previously in the review process.

As this review is primarily based on the headphone aspect of the Miniwatts many talents I will only touch on this lightly as an added attribute.

I found the characteristics of the sound to be clean, which had a little more sparkle and transparency than the onboard amplifier. Dependant on the amplifier type that is coupled to the n4 will determine a little more of its flavour but with my Emille KI40-L I found the in built DAC to be capable of reproducing music in a lovely and controlled manner.


The amplifier is extremely musical. There is wonderfully controlled, smooth detail throughout the frequencies and it has very good texture and layering of the soundstage. The Miniwatt n4 has a great tonal quality to it which makes it punchy, involving and doesn’t give a digital edginess to its character. It has a deliciously thick sound. I would have maybe liked a little bit of openness in the treble to balance out the thickness it has in the lower mids/upper bass region but can’t knock it for its non-fatiguing musical flavour.

More gain to the amp wouldn’t have been frowned upon either. I was using 250 ohm cans and feel it could be pushed further but there was no way of achieving this from the computers master volume, which is directly linked to the volume buttons on the front of the amp. Sound levels were very fair but then sometimes there is that track or two where you want to be able to push your headphones a little more.

I would have also liked the option for an outboard power supply which would separate it from the data side of things. We audiophiles do like to tweak. For portability though with a laptop it’s a fantastic design and a serious amplifier to have on the move.

The SPDIF output is a triumph and a fantastic added extra which I have never seen on a headphone amplifier before. What a wonderful idea to be able to link a computer to headphone amp and a hifi that doesn’t sport USB. Many DACs do these days as standard, but a lot of the oldies but goodies don’t…just like my own. I’ve never heard my Mac sound so good.

I love what my Creek OBH21SE does, however it sounds very different to the n4 and I can’t take it out with me. Both have characteristics that the other doesn’t and I could quite happily live with both.

An active set of speakers on the analogue DAC outputs to adorn the desktop or headphones for a more discrete listen or gaming session, along with the ability of SPDIF conversion for a larger hifi setup and you can appreciate how this little box could become the core of any computer based setup.Recommended 100 x 66px

Author – Dan

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