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REVIEW: miniwatt n4> > Amps & DACs > > REVIEW: miniwatt n4

Wednesday, February 5th, 2014

by Brian Hunter & Kevin Venable

Miniwatt is a Hong Kong based consumer audio company that released it's first product in 2009; The Miniwatt S1 tube amplifier. This amp and the subsequent N3 both garnered great reviews and a very heavy online following. Neither amp is currently available.

However, in 2012 Miniwatt released an opamp-based headphone amp and DAC, a very clear departure from it's previous tube based products. In fact the only things the products truly have in common, is that they look great on your desktop and have a reputation for stunning sound quality reaching beyond their price point.

A quick perusal of shows us the following technical design information:

  • USB 2.0 Async Mode (480 Mbits/sec), support 32bits/192k
  • USB Audio Interface for High-resolution audio file from PC/Mac
  • Support any sampling frequency to be up convert to 192 kHz
  • Electrical Noise Immunity via USB Digital Link
  • PCM1795 DAC with 32bits/192k 123dB Dynamic Range
  • LM4562 High Performance, High Fidelity Audio Operational Amplifier at analogue filter and driver
  • Independent L and R channel circuit at output stage
  • Digital Attenuation to deliver balance volume out (Digital Attenuation: 0 dB to -120 dB, 0.5db/Step)
  • USB-powered, no external power supply required
  • Dimensions: 115mm (L) x 74mm (W) x 20mm (H)
  • Finish: CNC Silver Powder Coated Aluminum Panel with Laser Etching + Stitched Leather Extrusion

They also supply more graphs and information on performance metrics than is usually provided by manufacturers in this price bracket, all easily found on the products page. Obviously Miniwatt is very proud of this product and they have every right to be.

Form & Function

The Miniwatt N4 comes in an understated grey box, but understatement stops when you lift the lid. This little marvel is slightly larger than a deck of playing cards shaped out of CNC lathed aluminum and wrapped in stitched leather. The product name is laser etched into the front right hand side above the single 1/8-inch headphone jack. On the left you find two buttons for controlling the digital volume attenuation, marked below with a - and +.

The back holds a full size USB connector, a RCA SPDIF jack, and a pair of RCA connectors for analog output. The inclusion of full size jacks is quite nice and allows for easy integration into current audio systems. The headphone output is rated at 100 milliwatts into 32 Ohms which might be why there is only a 1/8-inch headphone jack as the Miniwatt N4 is clearly designed for easier to drive portable headphones, though it was able to drive the Audeze LCD3. The 300 ohm Sennheiser HD650 nearly pushed the amplifier's capabilities to limit, but we were still able to get slightly-above-normal listening levels when running to the maximum.

Neither one of us is a fan of digital volume control. Kevin found it extremely hard to get the level right for his prefered listening level, things were always just a bit too loud. He found that using the N4 as a daily driver while working became troublesome. When you got the volume correct for streaming Spotify, alerts from email and Skype were ear shattering load. This didn't affect dedicated listening of course so can't be truly seen as a design flaw, just unfortunate.

Listening & Sound Quality

Brian Hunter: Miniwatt decided to go with the [TI PCM1795 chip] for the digital end of business. The chip is capable of 32/192 kHz but currently doesn't handle the portable-elusive DSD file type. Compatibility didn't prove to be an issue with any software I paired it with although a somewhat-unconventional two device labels of both "Speaker" and "SPDIF" appear in Audirvana's output options to the device.

Connecting a headphone to the front jack mutes the output to the analog outs in the rear. By isolating the DAC section via these analog outputs to a separate headphone amplifier I noticed what I hear quite often with portable DAC sections, the headphone amplifier frequently outperforms the DAC when space is a premium. Portable amplification seems to be a bit easier to hit the mark on than D/A conversion in restricted spaces.

Still, the unit sounds good as a whole considering the price. The DAC on the N4 offered good punch in the lows with respectable rendering in the mids and highs. Compared to the more premium-priced ALO International, the DAC section appeared to have just a bit more bass emphasis, but only slightly so. This additional bass didn't creep up into the midbass in an uncomfortable way, so I found it quite pleasing to listen to.

Much of this DAC responsiveness crept into the final results of the N4 as a whole package. The tiny package features and ever-so-slight bass increase with respectable fidelity and good top end extension. Compared to the standard headphone output on my Macbook Air, I noticed a much fuller sound, especially from the mids and lows that rightfully complemented the overall realism and articulation of the output.

Listening to Jimmy Webb's "P.F. Sloan" through the N4 produced a reaction that reached higher and filled in the dynamic vocals in a big way over the internal amplification of the Macbook. Although the laptop can push the LCD-3s to respectable listening levels, the N4 offered up more control, detail and presence, especially throughout the bass through mid frequencies.

From Miniwatt: "We're using premium audiophile grade components (Philips long-life aluminum caps and Japanese SMT components, etc.) and digital volume control (The N4 features balance output on both L & R channels if compared with traditional resistive volume control) to deliver audiophile grade-sound quality. The N4 is also firmware upgradable."

Kevin Venable: I spent a few weeks with my the N4 as my daily driver with the stock USB cable, and found it extremely detailed and engaging when streaming my usual Spotify playlists during work.

My playlisted are extremely varied, including everything from classical and small combo jazz to experimental electronic music and metal. The Miniwatt handled itself extremely well in the work environment including being used for Skype and Google Hangouts. When I decided it was time for some serious and deep listening I wired up the Miniwatt N4 with a Wywires LiteSPD 2.0 Silver USB cable from my MacBook Pro running Amarra HiFi and POW...

There is just something about the guitar playing of Johnny Winter. It has grit and depth, an emotional intensity that is hard to define. The N4 played grit and grime very well. Johnny's trademark in your face sound, smooth and aggressive at once, was engaging, even captivating when the Miniwatt was paired with the KEF M500.

As a guitarist myself the sound of the guitar is very important to me and this pairing delivered the goods. In fact the pair did so well with dirty guitars that I found my playlists gravitating towards guitar driven music. Mogwai, Porcupine Tree, Van Halen, Killswitch Engage, Trampled Under Foot, Gemini Syndrome, Serj Tankian, Mother Love Bone, and so on and so on ad infinitum. While the N4 will never replace a good tube amp and either vinyl or a NOS DAC in reproduction of texture and timbre, it does an adequate job of both and it doesn't just rock it can swing too!

I could feel the weight of the left hand as Hiromi pummeled the keys in the title track of her excellent 2013 Trio project album Move. Bass definition on the Miniwatt was excellent allowing me to differentiate easily the bass guitar and the piano, and showed a touch of the instruments harmonic texture to boot. The drums bit hard propelling the track forward in relentless momentum.

On Miles Davis's Birth of Cool the mid-range that helped the guitars come alive in rock-n-roll here made the horns sweet and silky. The track "Moon Beams" was especially beautiful, the horns harmonizing divinely.

The Change, My Girl from Ravi Coltrane's Spirit Fiction album is easily one of my favorite newer jazz tracks. Played through the N4 and the HifiMan RE-400 it proved a mournful though exhilarating experience. The moaning saxaphone floated above the rhythm sections solid yet fluid accompaniment and when the piano took it's all too brief solo I awaited each note with bated breath. The slight bass lift from the Miniwatt complimented the RE-400's weaker bass making this combination one of my favorites of those I tried.

The piano being so mesmerizing on the Ravi track led me to try Ola Gjeilo's modern classical album, Piano Improvisations, through the seriously over-achieving Pioneer SE-A1000 headphone. I found the piano tone to be good, with the right decay and ambience. Though it was enjoyable this was the album that made me miss my higher end amplifiers. Solo piano is truly difficult to get right. In fact using the Miniwatt N4 as a DAC with my Woo Audio WA7 improved the sound of solo piano immensely, though it wasn't as resolving of detail as the internal DAC on the WA7.


Stepping back and looking at the product from a strictly "what-you-get" vantage point it shapes up pretty nicely for the price. A head amp (with >10 ohms of output resistance), a USB converter, and a standalone DAC make the Miniwatt N4 a pretty nice package. But you are probably aware if you are reading this review, there are a lot of competitive products out there.

Still, not all (or even many) of the close competition flush out the full package you get with the portability of the N4. Even more direct-from-the-USB-port stick options are entering the market, most of which offer only a single mini-jack output, so the added flexibility of the Miniwatt is most welcome. The only things missing here that are featured on some of the close competitors are an analog input to utilize the unit as a standalone headphone amplifier or the ability to use it natively with an iDevice.

The N4 is almost a full collection of audiophile ins and outs in a very tidy package. It makes a great fit for someone looking for oodles of connections for high-resolution playback while on the go or even in a home stereo.

Competing in a very dense forest of portable DAC/Amps makes it hard to find your way through the trees, but if you have your sights set on something with plenty of digital versatility under $400 bucks and analog volume control or iDevice compatibility aren't a must-have then the N4 might just be your huckleberry.

This portable, leather-bound deck of cards can boost your listening on the go while the USB conversion flexibility makes a great tiny DAC for your computer-sourced stereo at home, should you choose to go that route.

The list price for the Miniwatt N4 is $348 plus $50 international shipping... but is currently going for $199 plus shipping. At this price it is even more of a bargain.

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