Review of three DACs: CEntrance DACport HD, NuPrime Hi-mDAC, Earstudio HUD100 MK2

[notaris]

Review of three DACs: CEntrance DACport HD, NuPrime Hi-mDAC, Earstudio HUD100 MK2
Small size - Big sound

Introduction

It is usually said that if one has a good pair of IEMs, and he wants to optimize the performance of his source, by just making a single investment, other than changing the source itself, then he should buy a good DAC.

Now, the DAC market is really huge, and if one tries to delve into it, he would probably feel lost. You have units that cost from $15.00 up to $100,000.00 (yes, it is correct). So, one has to be very specific on what he is actually looking for, and the first question is: Desktop or portable? The latter have gained a lot of popularity recently, as they combine good sound quality, mobility and reasonable price. So, I thought that I shall review some portable DACs.

Now, this is a good point to start, but then you can get easily get stuck: There is a huge selection of portable DACs in the market today, and obviously I could not review all of them; to be honest, I would not like to review all of them even if I could. I do believe in branded, good quality products, compared to the cheap alternatives that have flooded the market in recent years. Let me make clear that by “branded, good quality products” I do not necessarily mean something that costs a fortune; the price of a product is undoubtedly a factor and always taken into account in a review. However, in real life, you usually get what you pay for; as much as one finds bargains, equally he should avoid cheap, no name products.

I chose a bunch of USB DACs that one can easily find on many popular sites, among which Amazon and ebay. These are (in parentheses the MSRP):

1. Centrance DACport HD ($180).
2. NuPrime Hi-mDAC ($139)
3. Earstudio HUD100 MK2 ($100).

Some of them can be found on popular sites at a price better or substantially better than the corresponding MSRP.

All these DACs, in reality, are DAC/AMPs, so I shall concentrate my review on two main points: The sound signature of the DAC part, and the power of the AMP part; the latter would be judged by the unit’s ability to drive the Beyerdynamic DT 880 PRO headphones, having a nominal impedance of 250 Ω. Headphones with an impedance higher than 250-300 Ωare quite rare, so I thought there is no much reason to go further than that.

There are a few things that I would like to point out before I go on with the description and performance of each DAC:

1. There are certain parts in a DAC that play a crucial role in its performance. Probably the most important is the DAC chip employed, and of critical importance are the headphone Amp and the DAC’s microcontroller. However, the single critical factor in the DAC’s performance is how the whole design is implemented. To put it in simple words, a top DAC chip alone does not guarantee that the DAC would have a great performance, while a humble chip, with the proper implementation, can do miracles. So, don’t be impressed by the DAC chip alone.
2. The measurements of a DAC are important, and they must be as they are supposed to. It is accurate to say that good measurements is a necessary condition for a DAC with a good performance, but they are not a sufficient condition for great sound: You might have a DAC with almost perfect measurements, which, unfortunately, sounds cold and unpleasant. Of course, the same could happen with amplifiers, CD players, loudspeakers, earphones, you name it. So, you look at the numbers, but you also trust your ears; after all, all hi-fi products are a matter of personal taste.

Centrance DACport HD

Centrance is a small company based in Mount Prospect (close to Chicago), Illinois, designing and making in house recording and playback equipment mainly for professionals. Among them, there is a portable headphone DAC, by the name of DACport HD; the MSRP is $179.99, but occasionally it can be found in the market at a reduced price.

The DACport HD uses the AKM AK4490 DAC chip. This has been combined with custom-designed circuity for accurate reproduction of sound, without any added coloration or fatigue. According to Centrance, “custom clocking technology eliminates jitter for listening without fatigue” and “the DACport HD employs the AmpExtreme™ Technology in order to offer wide soundstage, clarity, detail and volume”. The Dynamic Range is 112 dB in regular position +14.5 dBu in max gain, the THD+N is 0.002% (FS,1kHz) and the Noise Floor is 7 μV RMS (A-weight) in max gain. Now, these are excellent specifications; however, what really makes the DACport HD to differentiate from the other DACs in our group is that it has a custom Class-A headphone amplifier with digital volume control, which is able to deliver 337 mW of power at 33 Ω and 56 mW of power at 300 Ω (for that the side button “GAIN” must be in the “HIGH” position). It is really astonishing that a small portable DAC is so powerful, to the point that it can drive 600 Ωheadphones with ease. The volume is controlled by a side-mounted wheel, which besides working flawlessly, it also brings some nostalgia of good quality devices of the past. The Class-A amplifier is the reason for the DACport HD getting a bit hot while connected, although never at an uncomfortable level.

The DACport HD is able to deliver PCM 32 bit / 384 kHz plus DSD playback, which is more than what one needs from a portable DAC. It is compatible with MacOS, Linux, Windows (10 and up, while a driver is available for Windows 7 and up), and it is USB powered through the supplied USB “micro B” cable. The output is a stereo 3.5 mm jack, headphone or line output.

The housing is made of aircraft-grade aluminum for scratch protection and durability, and the overall quality is outstanding. Its physical dimensions are 7.6 cm x 2.9 cm x 1.1 cm, and its weight is 36 grams; so, it’s not the smallest portable DAC in the market, but it is small enough.

Together with the unit, one can find in the box the USB “micro B” cable, a velvet pouch for protection and a Quick Start Guide.

NuPrime Hi-mDAC

NuPrime Audio is a relatively young company founded by a team of engineers led by the CEO of NuForce Jason Lim.They have already presented several interesting audio products, and Hi-mDAC is their second portable DAC; its MSRP is $139.00, but occasionally it can be found at a slightly reduced price.

The Hi-mDAC uses the Cirrus Logic CS43131 DAC chip. This is a new, low power audio DAC chip, combined with a high-fidelity headphone amplifier, providing good audio performance without draining battery life. According to NuPrime, “the CS43131 is designed with proprietary digital-interpolation filters in order to minimize pre-echos and ringing artifacts”, while “volume matching of the analog output levels and channel mixing enable a seamless transition between the DSD and PCM playback paths”. The S/N Ratio is > 100 dB (20-20 kHz A-weighted) and the THD+N is0.005% @ 1mW. It is not mentioned in the official specifications what the output power is; in a recent review NuPrime communicated 30 mW of power at 32 Ω, which appears way too conservative based on our listening sessions. The volume is controlled by up and down buttons at one side of the housing.

The Hi-mDAC is able to deliver PCM 32 bit / 384 kHz plus 256 DSD playback, which is more than sufficient for a portable DAC. It is compatible with MacOS, Windows 7/8/10 (through a driver), iOS and Android devices. Hi-mDAC is USB powered through a supplied USB-A to USB-C woven fabric cable, which appears to be of high quality. The output is a 3.5 mm analog or 3.5 mm optical (PCM 192kHz, DoP64) jack.

The housing is CNC machining from two pieces of aluminum, with the top having a silver tone mirror finish, and it is overall of very high quality. Its physical dimensions are 5.0 cm x 2.2 cm x 1.2c m, and its weight is 22 grams; so, it is quite small and lightweight.

Together with the unit, one can find in the box the USB-A to USB-C woven fabric cable and a Quick Start Guide.

Earstudio HUD100 MK2

Earstudio is a brand name of the Korean audio company Radsone (short for Radical Sound), and HUD100 MK2 is one of its DAC models; its MSRP is $99.99, but it can be found at a sale price.

The HUD100 MK2 uses the AKM AK4377 DAC chip. It also incorporates an ARM Cortex processor and MEMS oscillator in order to “implement Radsone's proprietary algorithm and minimize jitter”. The device has three different modes, acting like filters, which can be changed by a button in the front face plate:

• Bypass processing mode for pure sound enthusiasts.
• DCT processing mode for users searching for well-dithered analog-like sound.
• Dynamic processing mode for more powerful sound with balance.

There are two different outputs, a standard and a high power one. The Dynamic Range is 118 dB and the THD+N is -105 dB (0.00056%) in standard and -102 dB (0.00079%) in high power mode. The standard output is 0.914 Vrms (1.29 Vp) and the high power is 2.26 Vrms (3.20 Vp) (which one gets if he inserts his earphones or headphones jack in the “HP” output on the right of the front plate of the device). So, there are two power outputs, and the volume is controlled by your source device.

The HUD100 MK2 is able to deliver PCM 32 bit / 384 kHz plus 128 DSD playback, which is very sufficient for a portable DAC. It is compatible with MacOS, Windows 7 or later, iOS and Android devices. HUD100 MK2 is USB powered through a supplied USB-A to USB-C cable or a supplied USB-C to USB-C cable. The output is a 3.5 mm jack.

Although there is no information provided on the housing, it is most likely made of aluminum, and it is overall of very high quality. Its physical dimensions are 4.5 cm x 2.2 cm x 0.8 cm, and its weight is 21.5 grams; so, it is quite small and lightweight.

Together with the unit, one can find in the box the USB-A to USB-C cable, the USB-C to USB-C cable, a protective case with instructions on how to use it and a User Manual.

Performance

I write here performance, instead of just sound, because in each of the three devices we have a DAC and an AMP section, so I shall comment on each one of the two, and the combined result is what I call performance.

Sound

Soundwise all three devices share some common behavior, but they also have certain differences.

First of all, all three are generally balanced (with the differences noted below) and open; none of them is wide open, which really does not surprise me given that they are all portable devices. Furthermore, the soundstage and image in all three is about the same, at least, I could not detect any substantial differences that would make me to set one apart. However, whichever of the three is chosen will substantially improve the sound output of a PC, a laptop or a smartphone, so the investment is certainly worth it. The whole of the audio spectrum is reproduced in an articulate and engaging way, and there is a big difference from the usual flat and indifferent sound that comes out of a computer’s or a smartphone’s DAC.

The sound of DACport HD is very dynamic, due to its Class-A headphone amplifier, which is able to deliver 337 mW of power at 33 Ω and 56 mW of power at 300 Ω, a truly impressive output. This is undoubtedly the strongest point of DACport HD. On the other hand, its sound is the warmer among the three devices. By that, I do not mean that there is an inclination towards the low end of the acoustic spectrum, to the point that the presentation is imbalanced, which is not; it is that the sound of DACport HD has just a click of warmth compared to the other two devices. Actually, in some musical pieces, one might get the impression that the presentation is somewhat U shaped, although this might be due to the fact that the sound of DACport HD is very dynamic.

The main characteristic of Hi-mDAC is its relaxed presentation, which is the most balanced of the three devices. By “most balanced” I do not mean a big difference from the other two, but rather that the Hi-mDAC is the most neutral of the three; not a touch of warmth, not a touch of brightness and not any kind of forwardness in the music or vocals. A puzzle is the output of Hi-mDAC; on paper, it appears to be much weaker from what it actually sounds. Its sound is by no means as dynamic as that of DACport HD, and this might contribute somewhat to its neutrality, but it is not weak either. All in all, the main characteristic of Hi-mDAC is its neutral presentation, and because of that at times it might appear to be a bit on the dark side.

The main characteristic of HUD100 MK2 is its bright presentation, to the point that in some cases might sound a bit harsh. This is not in general annoying, although in some musical pieces and certain spots might bother some people. On the other hand, this could be favorable for some others, although I think that between a “warm” and a “bright” presentation most people prefer the former. Other than that, HUD100 MK2 is very powerful; I would not say as much as the DACport HD, but certainly more than sufficient. Furthermore, I tried quite hard to see the difference between the three different modes, Bypass, DCT and Dynamic, but honestly whatever difference exists is hardly detectable, probably in a few specialized musical pieces.

The sound testing on all three devices was done on a variety of musical pieces from TIDAL, varying from the classical song “Always in my mind”, beautifully performed by Elvis Presley, to the really powerful, but not for everyone, piece “Move” of the Japanese artist Hiromi, to the wonderful “Fanfare for the volunteer” by Mark O’Connor, to the authoritative Rachmaninoff’s “Symphonic Dance #3”, and finally to the beautiful song “Peel me a grape” by Dianna Krall. In all these different musical genres, my impression was what (or almost what) I described above.

Power output

A brief description of the power output for each of the three devices has already been given. Without any doubt, the most powerful is the DACport HD, followed by HUD100 MK2, with the essential difference that in the former the volume can be controlled by a side-mounted wheel, while in the latter cannot and it is fixed at two different sound levels. The power output of Hi-mDAC appears to be kind of a mystery; although it is not at the same level as that of DACport HD, it is close by to that of HUD100 MK2 and it gives the impression of a much higher output than the theoretical figure of 30 mW at 32 Ω, which was communicated by NuPrime. Whatever the case might be, the power output of Hi-mDAC is more than sufficient and it has the advantage, like DACport HD, that the volume is controlled by up and down buttons at one side of the housing.

All three devices were paired with the new, high quality IEM Final A4000 model (a review is coming soon), which is an easy load having an impedance of 18 Ω, and the Beyerdynamic DT 880 PRO, which is a rather heavy load having an impedance of 250 Ω. None of the three devices had any problem to drive DT 880 PRO.


Comparisons

To Audioquest DragonFly Black, Red or Cobalt

The first comparison of DACport HD, Hi-mDAC and HUD100 MK2 was made against the three Audioquest DragonFly Black, Red or Cobalt, which all three represent what one would call the “standard” in the market. The Black uses the ESS Sabre ES9010K2M DAC chip, the Red the ES9016K2M chip and the Cobalt the ES9038Q2M chip; the corresponding MSRPs are $99.00, $199.00 and $299.00, respectively.

Soundwise all three DragonFlies are undoubtedly very good. The Black and Red are very close to each other (in most cases they are almost indistinguishable), and the main difference between the two is that the Red is more powerful, having an output of 2.1 V compared to 1.2 V of the Black; the latter explains the popularity of Red among all DragonFlies. The Cobalt is the most revealing among all DragonFlies, to the point that in some musical pieces and certain spots it might sound a bit harsh to some listeners, and it has the same output as the Red. To me the extra output of the Red and the improvement in sound of the Cobalt does not justify to double and triple the price of the Black, respectively.

The sound of any of our three devices is at least as balanced, detailed, open and engaging as any of the three DragonFlies, including the Cobalt. The HUD100 MK2 is almost as revealing in the upper end of the audio spectrum as the Cobalt at a fraction of the cost, although I have to admit that the latter is more balanced than the former; and although the sound of the Black and the Red is very good, I find the sound of DACport HD and Hi-mDAC, overall, more articulate. I don’t want to be misunderstood: All DragonFlies are very good, and I understand their popularity; however, the Red and the Cobalt are too expensive based on what they offer, so our three devices represent certainly a better choice. The Black is competitive in price, but it is behind by a narrow margin in performance.

To Resonessence Labs HERUS+

The other comparison of DACport HD, Hi-mDAC and HUD100 MK2 was made against what I consider a reference portable DAC/AMP, the Resonessence Labs HERUS+ (an upgrade of the original HERUS). The HERUS+ uses the ESS Sabre ES9010K2M DAC chip (the same as the DragonFly Black), and its MSRP used to be $395.00, so it was not cheap. On the other hand, the design and implementation of the HERUS+ was done by the people who designed and implemented the ESS Sabre chips (Mark Mallinson, the owner of Resonessence Labs, was formerly Director of Operations in ESS Sabre), so they took full advantage of the ES9010K2M’s abilities. The result is a portable DAC that is made like a tank, it is a pleasure to look at and a bigger pleasure to listen to; it has a sound that is balanced, detailed, engaging and wide open.

HERUS+ is better, by a smaller or bigger margin, than any of our three contenders in almost every aspect, except for the power output where the DACport HD has the lead; however, it is the soundstage and image in which HERUS+ has a clear dominance. Now, maybe it is not fair to compare HERUS+ with our three devices, as it costs at least twice as much and, essentially, it is a miniaturization of a desktop DAC; and maybe this comparison does not make much sense either, given that Resonessence Labs closed down its doors at the beginning of 2020, so it is impossible for someone to buy this wonderful DAC anymore. Granted! But I thought I should give you a measure of comparison for those who happen to know HERUS+ (or HERUS for that matter).


Conclusion

Whenever one does a comparative review of more than one devices, the readers expect to see at the end a classification. So, the question is, which of the three, DACport HD, Hi-mDAC or HUD100 MK2, is the best? First of all, there is no point to give you my personal opinion based on my personal taste. On the other hand, an objective opinion is not an easy task: How can one rank three devices when the emphasis, or if you want the strong point, in each one of them is on something different? The DACport HD has the emphasis on its dynamic presentation and high power; the Hi-mDAC on its neutral presentation; and the HUD100 MK2 on its bright presentation.

First of all, I want to stress that one would not make any mistake by choosing any of the three devices. They all have a detailed, balanced, engaging and open sound and more than sufficient power, while the differences between them are quite small. Now, if you want me to be more specific: If dynamism and high power is what you care the most, then you go with the DACport HD; if balance is your cup of coffee, then you choose the Hi-mDAC; and if you love bright presentations, then you go with the HUD100 MK2. Also, in DACport HD and Hi-mDAC the user is able to adjust the volume, and this is an extra benefit.

Personally, I am fond of neutral presentations so, based on what I wrote above, I should choose the Hi-mDAC. Well, probably; since, while writing the review, I found myself, in several occasions, to want a device that has the balance of Hi-mDAC with the dynamism of DACport HD.

All three devices, DACport HD, Hi-mDAC and HUD100 MK2, are among the best portable USB DACs in the market today. They are all recommended, with the first two most highly.

https://centrance.com
https://nuprimeaudio.com
https://earstudio.store