Excellent driving power, Outstanding soundstage width, Optical output, Wide file support, Low output impedance and black noise floor
Housing has sharp edges, Brighter background won’t suit all, Lighter sub-bass
The Hi-mDAC isn’t perfectly neutral but provides an open, tonally transparent and surprisingly expansive listen at a compact price and size.
The Taiwanese company NuPrime is a fairly new name to the audio industry and certainly reminiscent of NuForce with which many will be familiar with. The name change occurred when the company was re-acquired by its co-founder Jason Lim who bought back the high-end division and formed the new company. NuPrime focus on in-house research and development, with their own engineering and design team, they are able to deliver highly competitive pricing for the consumer. Their main focus is high-end reference sources that extend well into the 4-digit price range. Yet, here for review is a very accessible portable DAC/AMP with a modest 139 Euro price tag. The Hi-mDAC is the company’s first portable source and one that filters down a lot of their team’s expertise. You can read more about NuPrime and the Hi-mDAC and treat yourself to one here.
I would like to thank NuPrime very much for providing me with the Hi-mDAC for the purpose of review. All words are my own and there is no monetary incentive for a positive review. Despite receiving the DAC/AMP free of cost, I will attempt to be as objective as possible in my evaluation.
Tech Specs –
Input: 1 X USB (32-bit/384kHz & DSD256 decoding)
Output: 3.5mm analogue or 3.5mm optical (PCM 192kHz, DoP64)
Frequency Response: 20-20kHz +/- 0.5dB
S/N Ratio: > 100 dB (20-20kHz A-weighted)
THD+N: 0.005% @ 1mW
Dimensions: 5.0cm x 2.2cm x 1.2cm
The Pitch –
Cirrus Logic DAC
The Hi-mDAC is using the CS43131 lower power DAC with integrated amplifier. It can decode up to 32-bit/384KHz PCM and native DSD 256. The DAC also features optical output in the form of S/PDIF and DoP stream. The integrated amplifier is capable of outputting up to 2v RMS into a 600ohm load and around 30mW per channel into a 32ohm load. This means heaps of volume and pretty decent current output for a low-power chipset. Furthermore, NuPrime is using their own discrete USB communication chipset which has wider support than the XMOS 2XX chips more commonly available on the market.
The Hi-mDAC is CNC machined from two pieces of aluminium with mirror glass faceplate. It’s a very industrial design with squared-off edges and a rugged texture that provides great tactility. The level of finish is good but not outstanding. For instance, the two halves of the housing were slightly offset on my unit as can be observed above. I would also have preferred smoother edges as the sharp corners may scratch the accompanying device if not used with a case and screen protector.
Otherwise, it’s a clean and minimalist device. There’s a USB-C input on one end and headphone/optical output on the other. The left side houses matching aluminium volume buttons that provide a satisfying clicky action. The mirrored faceplate also houses a status LED that only becomes visible when the device is powered on. Ultimately, the design is attractive while upholding convincing density and sense of quality, just watch those corners.
The Hi-mDAC will be immediately familiar to anyone who’s used a portable DAC/AMP before. There’s a driver on NuPrime’s website, however, I found it was recognized without it on my Windows 10 laptop. The DAC also functioned perfectly with my Google Pixel 4. It automatically powers on when connected to a source, through which it derives power, and a headphone or earphone is connected to the output. When either is removed, the device powers off.
Listening to the Hi-mDAC, there is clearly very solid power at play, however, I did also notice a fairly obnoxious pop when plugging in or unplugging earphones or the DAC itself. As such, it’s best to ensure no music is playing before plugging the earphones in. This is good practice, but not something that most DAC/AMPs require these days. There are a plethora of very fine volume steps which is great for those that intend to use them for both IEMs and headphones. However, conversely, it can become tiring shuffling through so many volume steps between gear of different sensitivity.
As always, there are fundamentals we expect from a good quality audiophile source. With a portable DAC/AMP such as this, huge driving power is not feasible, especially given the limited output power offered by most source devices to power them. As such, it is reasonable to instead prioritise a linear frequency response, low output-impedance and an absence of hiss and interference. I’ll be analysing the performance of this DAC/AMP in isolation, then by comparison to competitors in its price and form factor to better establish price/performance and its best use cases.
Frequency Response –
Testing Methodology: RMAA via Startech External Sound Card
The Hi-mDAC measures perfectly linear with no bass roll-off or other oddities, thereby, reproducing audio with great fidelity and without introduction colouration. Due to the quality of my sound card, I am unable to reliably test other measures such as distortion and crosstalk so they will be used as a personal reference only. Qualities here can also impact the sound as I will detail via subjective listening.
Output Impedance & Hiss –
Testing Methodology: SPL volume matched comparison through an inline splitter to JDS Labs Atom + Khadas tone board to Campfire Audio Andromeda
Comparing between the Atom and Hi-mDAC provided very similar tonality to the extent that I would suggest the NuPrime has a sub-1.5-ohm output impedance. This is expected given that this is an integrated Cirrus amplifier which generally produces such results. As such, the Hi-mDAC will be a great choice for low-impedance multi-driver IEMs and will not skew their signature. This is compounded upon by a black noise floor. On low to medium volumes, which was all my ears could handle with such a sensitive IEM, I noticed zero background noise. No hiss, no odd interference, I would intimate that the Hi-mDAC is well-shielded and will be a great companion to laptops and phones as a result. As such, this DAC/AMP is a great choice even for low-volume listeners with sensitive IEMs who want a perfectly black noise floor.
Though I am confident in NuPrime’s products, I was apprehensive about the Hi-mDAC’s lack of specifications. Many manufacturers are proud to tout their ruler flat measurements and specs on their website, however, few are to be found on NuPrime’s. That said, what I hear here is a very sound Cirrus implementation that carries the strong traits of an integrated chipset. Despite my best efforts to volume match, I did hear a slightly brighter presentation from the Hi-mDAC but one that was underpinned by excellent technical ability with clean, defined transients. As always, this being a source with low output impedance and a linear frequency response, my sound analysis comments will be referring to the minutiae that cannot be compared to the differences between different earphones per say.
Testing Methodology: SPL volume matched comparison through an inline splitter to JDS Labs Atom + Khadas tone board to Custom Art Fibae 7 (flat impedance). Powered by Pixel 4 with Poweramp Pro via high-resolution output.
Immediately, sub-bass extension is good but not its strongest asset, lacking the extension and power of the desktop stack, which is to be expected. That said, this impression was exacerbated by the Hi-mDAC’s generally lighter sub-bass character, with slightly softer slam and rumble in exchange for a smaller note size that enables greater separation through the mid-bass. The remaining bass is linear and very clean as a result, aided by concise attack and quick decay that uphold great pace and low-end organisation. This is an especially punchy and highly defined presentation with good dynamics, if one that’s lacking just a little depth.
The midrange is transparent besides a hint of additional vocal extension that gives it an open presentation. Mids possess neutral tone and body, instigating an accurate timbre to both vocals and instruments. I hear the slightest addition of energy in the upper-midrange that grants its open and floaty character, trading density and placement stability for enhanced clarity. Vocals are also brought slightly forward though without becoming intense or thin. Still, notes have more substance on the desktop setup in addition to higher resolution. Regardless, for a portable source, the presentation is well-resolved and is especially tonally neutral which will surely suit warmer IEMs and headphones.
Highs are slightly aggressive in terms of detail presentation and the background is a touch brighter than my desktop stack too. There’s a hint of warmth to foreground treble instrumentation, they are portrayed with convincing bodied and euphony which mitigates some of the DAC’s brightness. Meanwhile, note attack is sharp and decay is on the natural side, producing a densely detailed and textured portrayal of instruments while retaining pleasing control and composition. The background is slightly bright which brings background details to the fore. Resolution is surprisingly good as is extension and micro-detail retrieval but I find the background to glare over these fine details in some instances, again I find this source to appeal best to warmer, smoother earphones where listeners will find it to invigorate their presentation.
It is with regards to soundstage that the Hi-mDAC performs best, crafting a very spacious presentation that belies its diminutive form factor. Width essentially matches the desktop stack while depth is just slightly more intimate due to its slightly forward vocals. Its main downfall is imaging, which certainly offers a keen sense of direction due to clean and defined transients, but also less stable positioning. The centre image is slightly diffuse with a tendency to push vocals and instruments to the sides. Furthermore, layers aren’t especially defined as there is reduced foreground/background contrast. This also affects treble separation though their transient response does do a lot to redeem fine details there. Separation is best showcased in the bass and midrange where the source is more transparent and performs at a good level.
Driving Power –
Meze Rai Penta (110dB, 20 ohms): The Penta is efficient and scales very well with clean power. Sub-bass is lacking just a hint of weight but is very tight. Meanwhile, mid-bass is defined with keen attack and natural decay. Mids are slightly forward but natural in timbre and tone. Highs are very well-detailed with pleasing air and resolution. The soundstage is very wide, slightly more intimate in depth and imaging is sharp. No hiss.
Final Audio E5000 (93dB, 14 ohms): There is plenty of volume and good extension, the NuPrime actually helps to clean up the low-end with reduced sub-bass presence and a more separated mid-bass. Notes are defined with good attack and drive. Mids are natural and retain their smoothness, there’s a hint of additional vocal intimacy and clarity which is also welcome on the warm, dense E5000. Highs are well-detailed with clean transients and the background is black. The soundstage is very large and imaging is sharp, a great pairing with no hiss.
Hifiman Sundara (94dB, 37ohms): Being a planar the Sundara needs some power and a low output impedance. I was very shocked by this pairing, the NuPrime did a terrific job driving these headphones. Surely, the Atom provided a more sub-bass depth and power, but the mid-bass was tight and well-present on both, dynamics were surprisingly convincing. The mids and highs very much resembled each other, vocals were just a touch warmer on the NuPrime and cleaner on the Atom but similar in size and positioning. There was a touch more resolution on the desktop setup in the highs in addition to slightly more defined layering and a slightly larger stage. But again, the presentation was very convincing on a whole from the NuPrime.
Cirrus state 30mW per channel into a 32-ohm load which sounds appropriate for a DAC/AMP this size. However, as it’s not stated on the NuPrime website, I have no real way of discerning its actual specifications. That said, I do hear very solid driving power for a compact, portable source. I would suggest that use cases for the Hi-mDAC are similar to the DragonFly dongles, being sufficient for in-ears, portable headphones and some full-size headphones. I wouldn’t want to power a 600-ohm behemoth, but even modestly efficient dynamic driver and planar headphones actually sound quite convincing with the mDAC. Due to its tonality, I find it to best suit smooth, warm gear where it injects a bit more clarity and openness.
Shanling UP2 ($79): The UP2 makes for interesting comparison as one of the more concise and balanced sounding Bluetooth receivers I’ve tested. Both represent great solutions to the jack-less smartphone epidemic. The Hi-mDAC provides noticeably better sub-bass extension but both have a similarly light quantity here, producing a slightly thinner note body and more separated mid-bass. Notes are more defined on the Hi-mDAC, the UP2 having a slower decay and softer attack.
Through the midrange, both have a similar intimacy, the Hi-mDAC having a more forward vocal presentation, the UP2 just having a narrower presentation. The Hi-mDAC has higher resolution and note definition, it is more tonally transparent while the UP2 has a touch more warmth. Up top, the Hi-mDAC is more detailed with noticeably more extension and air. The UP2 has a smoother foreground and its transients are hazier. The Hi-mDAC has a much wider soundstage while the UP2 is more intimate but with a more stable presentation.
Zorloo ZuperDAC-S ($89): The ZuperDAC is a more dynamic source, quite linear besides a slight sub-bass bump. It offers more depth and a surprising amount of additional sub-bass weight at the very bottom. Its notes are thicker and fuller but its transients are a touch hazier. Still, the ZuperDAC plenty of attack and a very punchy low-end where the Hi-mDAC is more neutral, somewhat clinical and less dynamic. The midrange presentation is quite similar on both, being fairly neutral in body and a touch forward in positioning.
There’s a slight warmth on the ZuperDAC from its more prominent low-end. Meanwhile, the Hi-mDAC is more neutral but slightly more vocal forward. It has noticeably higher note resolution and definition than the ZuperDAC, sounding more refined. Up top, the Zorloo is more aggressive once again but also thinner and less detailed with the Hi-mDAC being more realistic if with a brighter background. The Hi-mDAC has better extension with greater background detail retrieval. The Hi-mDAC has a larger soundstage with sharper imaging.
Cozoy Takt Pro ($289): The Takt Pro is a bit more linear sounding overall, chiefly due to its low-end. There is noticeably more sub-bass power and depth on the Takt Pro. Furthermore, the mid-bass carries a light warmth granting it a fuller note body and more solid punch. The Hi-mDAC is cleaner and more separated with similarly concise attack, however, overall it is less commanding. The midrange follows suit, the Hi-mDAC offering a touch more clarity and extension, the Takt Pro greater body and density. Resolution is higher on the Hi-mDAC and the presentation is more clinical while the Takt Pro is smoother and more musical.
Up top, both sound similar, being slightly crisp with sharp note attack, the Hi-mDAC ‘s transient response being a touch sharper though I hear similar extension and resolution here. The chief difference is the background, being darker on the Takt-C, brighter and more open on the Hi-mDAC, suiting different pairings. Nonetheless, the Hi-mDAC has a noticeably wider soundstage where the Takt Pro has more depth on behalf of the mDAC’s more intimate vocal presentation. Imaging is just as sharp on both with the Takt Pro offering a more stable presentation with a stronger centre image, the Hi-mDAC have more defined layers and atmosphere.
JDS Labs Atom + Khadas Tone Board (~$200): The budget desktop reference setup offers a very transparent sound throughout and I subjectively hear a small sub-bass emphasis. Much like the other sources, it has noticeably more sub-bass body, both as a result of greater linearity into the lowest lows and better extension and drive. The setup has a slightly thicker note body, its attack isn’t as fast but decay is quicker so separation and note definition are essentially as good. The midrange is more transparent in size and position on the Atom/Khadas with the Hi-mDAC being more forward and clear but also a touch bright and nasal in terms of timbre. Up top, the desktop setup is again, more linear with a touch more detail retrieval in the foreground and sparkle at the very top.
It is more easily discerned as the background is cleaner and darker, granting it more foreground/background contrast and more defined layers. The desktop rig has a slightly larger soundstage and more stable imaging. We would all expect this given the size differences and less conventional presentation of the Hi-mDAC, yet many would consider sources to be just as much about synergy as about individual performance. Still, the benefit of a reference setup is that it enables the characters of other gear and the source material to shine through and, therefore, for myself especially as a reviewer represents the ideal.
Starting at the basics, the Hi-mDAC ticks all the boxed; the output impedance is low, the noise floor black to my ears and the frequency response ruler flat. Add on high volume output and strong driving power that even suits some full-size headphones and this is already a very versatile purchase. The bane of the compact source is that it sounds, well, compact. A few have bucked this trend, offering surprising refinement though none that I’ve tried have really broken out of that box. And it with regards to this quality that the Hi-mDAC finds its the strongest asset, delivering a grand, expansive soundstage that essentially matches an entry-level reference desktop setup. That’s not to say that it mirrors its presentation, but it does get shockingly close at times. The caveats will come down to its slight brightness within the upper-midrange and middle-treble meaning that it best suits a warmer setup alongside its sharp-edged design. Otherwise, the Hi-mDAC really surprised me, it isn’t perfectly neutral but is open, tonally transparent and surprisingly expansive listen at a compact price and size.
The Hi-mDAC is available from on NuPrime (International) for EUR 139 at the time of writing. I am not affiliated with NuPrime and receive no earnings from purchases through this link.