Pros:  Tiny form factor, excellent build quality, nice looking, easy UI and intuitive control scheme, ton of power, good battery life

Cons: no external DAC, no line-out, no gapless (on the way?), limited playlist capability, screen protector unusable

List price: $399

Acknowledgment

Thank you HiFiMAN for providing this review sample in exchange for my honest opinion.

An earlier version of this review was posted on HeadFi.

Introduction

HiFiMAN has been around a long time now. They’ve gone from bargain OEM to one of the best and brightest headphone manufacturers in the world. Personally, I have a long history with HiFiMan.

In 2009, I had gotten tired of my $70ish Sony IEMs (can’t remember which ones they were and tossed them long ago) and was looking for a new pair of budget headphones to play out of my PSP—dated. Through |joker|’s thread, I discovered the RE0, and through the extinct Head-direct website, I got my first pair of audiophile headphones for $80. It was a really good deal, and the start of something beautiful and terrible, a love and lust for new audiophile gear. In a way, HiFiMAN provided me with my gateway drug, and all of you on HeadFi are now regretting it.

My first post on HeadFi after years of lurking was a 3 way review comparing the RE0 to two closed circumaural headphones: the Shure SRH-440 and the KRK-KNS 8400. It did pretty well.

I’ve listened to a lot of HiFiMAN gear, and still have my RE0. The HE-6 is probably my favourite headphone of all time when properly driven, and the HE-1000 is among my current favourites in production headphones—I haven’t been able to do side by side with the Focal Utopia or Mr. Speakers Ether (C) Flow, so can’t state that the HE-1000 are my favourite outright. With all the listening I’ve done, I hadn’t yet had the opportunity to do a true review of some HiFiMAN gear, so when they called for reviewers, I jumped, in spite of a busy review schedule that won’t resolve itself before the new year.

If you’d like to know more about your humble reviewer, here is a link to my story. I’m sticking to it.

Form & Function

Form

The SuperMini is sveldt yet powerful. It is light and firm in the hand with clean, solid lines machined from a single block. There are no visible screws—stylish! The screen glass is thick and looks like it will hold up to some beating from the thickness—I didn’t test it, but it would be pretty cool to see a durability test on this one. I think it might perform really well. It would perform even better if the screen protector was functional. I had two SuperMinis sent to me due to problems with microSD card compatibility and formatting—you’ll see more below—and I wasn’t able to apply the screen protector on either without it being completely covered in dust. Another reviewer, thatonenoob (whose written a great review), found that the screen protector had dust on it before he even attempted to apply it—it was dusty out of the factory. This isn’t good enough for a screen protector. Ideally, the unit should come with a screen protector applied, and a spare screen protector. HiFiMAN needs to step up their screen protection game. It wouldn’t take the Golden State Warriors, not even the Orlando Magic, to be scoring all over this flaccid screen protection.

The screen is a simple black and white OLED with good viewing angles that does alright in the sun. I think that is just fine for this type of machine. This thing isn’t designed for fancy displays, it’s supposed to be designed for power and efficiency. If this thing output some colour on that display, I’d expect that a sacrifice would have to be made in power output to maintain battery life performance. If you want a fancy schmancy display, there are lots of players that can do that, but how many of them advertise 22 hours battery life (more on this later)?

The SuperMini uses a three button layout on the front. None of the buttons have labels, instead the screen tells you what the buttons do. Other buttons for power, a back button and volume controls are on the right side of the player. Personally, I much prefer the button layout of the MegaMini, it’s more intuitive and I can access all the buttons that I use regularly with my thumb. The back button is a pain in the butt to use on the SuperMini. I imagine the buttons are distributed in the way they are because of that chain of 8 op amps that must be running on the left side of the player down to the balanced and single-ended headphone jacks at the bottom of the player.

The headphone jacks are right next to each other. In fact, they are so close to one another that you can’t have two headphones plugged in at a time. I wanted to use two 2.5mm balanced adapters to test what the difference between balanced and single-ended is on the player, but I can’t plug both adapters in at the same time for the cable, which means that my time lag between switches is longer. This isn’t a good thing. Like others have said, a bit more distance between the two headphone outs would be good, and not just to prevent plugging the wrong stuff into the wrong jack. Unfortunately, I’d bet that there wasn’t any room on the board layout for having greater separation between the headphone outs. This is one of the sacrifices of being small.

Also on the bottom of the player are the microSD slot, and the micro USB slot. The microSD slot has a deep actuation point and doesn’t have a dip like the MegaMini to make it easier to insert the card. I had some difficulty having cards stick and really had to get my finger nail up in there. Like on the MegaMini, the micro USB slot isn’t deep enough. I found the micro USB plug hangs half-way out of the slot. This is a recipe for a damaged slot, damaged cables, and intermittent charging. When the SuperMini is connected, I don’t feel confident about moving it.

Function

The operating system on the SuperMini is much the same as the MegaMini, so you can head over to my MegaMini review for more about that. The only differences are that the Playing Now screen doesn’t have any art, it instead gives a bit more information, and it’s all in black and white.

Another difference I found is that the MegaMini had no problems with any microSD cards I used whilst this SuperMini unit told me to format my cards every time I put them in. This led me to sending one review unit back to HiFiMAN as I thought that maybe the reader was broken. The second unit had the same problem. To get the machine to work I had to format the card in the machine, and then plug it into a computer to load music, as every time I took out the microSD I was told to reformat again. I’m glad it worked, as otherwise all I would have been able to say about the unit was that it was defective, instead of being able to comment on sound. HiFiMAN needs to fix this immediately. The two cards I used were the Sandisk Ultra 128GB and 200GB cards, two of the most common and most popular memory cards for audiophiles. A production unit shouldn’t have these problems and HiFiMAN risks alienating those who purchase the SuperMini if they have problems. Christmas is too far away for a fix on this problem. The solution should be there, as the MegaMini has no problems with microSD cards.

The battery life of the SuperMini is listed by HiFiMAN as up to 22 hours. I have a feeling that test was done with 128kb/s MP3s at next to no volume, as when playing mixed redbook FLAC and HiRes content, I only got 11 hours and 42 minutes with a combination of the Vibro Labs Maya and UERR as load. When I tested again using the included nameless headphones in balanced mode I got about 10 hours, and similar results using the HD600—that’s impressive. I don’t think they need to advertise 22 hours of utterly fabricated or completely unrealistic playtime. Getting 10 – 12 hours playing a mix of HiRes and redbook is good enough for such a tiny device with so much power, driving the HD600 for 10 hours is downright impressive.

Those nameless included headphones

The headphones included are pretty dang good. They’ve got an open sound that edges a bit towards the bright end in the treble and is smooth in the bass. Mids are presented at a slightly forward depth. It’s a pretty common and pretty popular tuning. The soundstage on them is good.

The headphones are too good to be given the disrespect that HiFiMAN gives them in the box. They come with two sizes of double flange tips, medium and large, and neither of them fit my ears at all, and these things need a perfect seal or they sound very thin. HiFiMAN put these in the box and treated them like hot garbage. These should come with standard accessories that IEMs come with: a little pouch, three sizes of silicone single flange tips, one pair of medium foamies (preferably a medium and a large), an actual presentation spot in the bottom of the box instead of tossed in like an afterthought in plastic coated wire wrapping in the empty space below the SuperMini presentation area.

Audio quality

The SuperMini in single-ended is better than the MegaMini, but not better than the DX50. The MegaMini has a bit less dynamism and stage depth compared to the SuperMini, but the SuperMini in single-ended doesn’t sound as musically thrilling as the DX50, it’s still kind of flat sounding (not in the good way) and it doesn’t impress that much. But when you switch to balanced mode…

That’s weird, this usually only happens when I’m alone (from memes4laughs)

The background is blacker in balanced mode, which allows the sound to be more dynamic. The stage is bigger. Notes are fuller and dynamic range is extended. It is just better.

The other benefit of balanced is sheer driving power. This driving power allows the HD600 to be driven comfortably. I hooked up my HD600 to the balanced output using a WyWires Red and a DIY Neotech OCC copper XLR to 3.5mm TRRS adapter made for me by my local wire wizard. The HD600 sounds how it is supposed to sound. While it can be driven even harder and made to sing in an even richer character with amps like my Airist Audio Heron 5, the SuperMini does an amazingly good job and it’s smaller than a Snickers bar. That is friggin’ impressive. The DX50 can’t drive the HD600 with any authority, and that is a significant coup for this miniature marvel.

Comparisons

For comparisons using the Maya I volume matched using a dB meter and white noise to 78dB, for the Maya, and 72dB for the UERR. I found that because the insertion is deeper on the UERR, I don’t need as much volume. All tests were done with single-ended outputs as I had no way to keep cables consistent across single-ended and balanced mode operation. My general approach to comparisons is to control for the variables that I can so that my comparisons are as fair as they can be.

MegaMini

The sound signature of these two is nearly or completely indiscernible to me at matched volumes. I tested with the Vibro Labs Maya, and couldn’t consistently tell a difference between the two players’ signatures, which is a good thing, they are both fairly neutral players. Both players have some low level hiss with the Maya, but I think this is going to the case for the Maya on many rigs—I got some soft hiss at low volumes with the Maya on the iBasso DX50 also. I thought I heard a bit more depth and body in the SuperMini, but that may be expectation bias, as I’ve already read HeadFi user Brooko’s excellent review of the SuperMini and the measurements show lower distortion, which in my experience has usually improved depth. Short story shorter: I can’t confirm any differences between the Minis whilst using the Maya.

Switching to the UERR, the SuperMini sounds like it has a little bit bigger soundstage when listening to Amber Rubarth doin’ some Tom Waits on Hold On. Differences are small and still subject to all the biases that come with non-blinded testing. It might all just be in my head, and not just because the UERR are several mm closer to my brain than the Maya.

I like the simple black and white screen on the SuperMini better. Navigation is basically the same between them, but the playback screen tells me more on the SuperMini. I found the CD picture in the middle of the MegaMini screen pointless—it didn’t display album art for me.

iBasso DX50

In single-ended mode, the DX50 still slays the SuperMini. When you switch over to balanced mode, though, the background is cleaner, the stage is more open and it can drive a pair of HD600 headphones like Burt Russell in a Trans Am. Watch ol’ Bandit run! Did you know that Smokey in the Bandit was second only to Star Wars in 1977 for theatre sales? I didn’t.

Vital Statistics (specs from manufacturers and distributors)

So what does the manufacturer have to say about this piece of kit? Sometimes it’s enlightening, sometimes not. First, here are some measurements. HiFiMAN didn’t provide the output impedance value, which is pretty ridiculous as it significantly affects sound and purchasing decisions for those in the know about impedance mismatches. Correct that, HiFiMAN.

Specifications
Price	$399
Dimensions	45mm x 104mm x 8.5mm (1.77” x 4.09” x 0.33”)
Weight	70g (2.47oz)
Frequency response	20hz – 20kHz
Output Impedance	~2Ω (as measured by HeadFi user thatonenoob, comment linkie)
Total Harmonic Distortion	0.04%
Signal to Noise Ratio	102 ± 3dB
Power Output	320 mW into 32Ω (balanced output), no data given for SE
Battery life	22 hours stated
Formats supported	16/44 to 24/192 WAV, FLAC, ALAC; 16/44 to 24/96 APE; DSD64 (single rate, DSF and DFF formats); also supports MP3, OGG, AAC, WMA
Memory	MicroSD to 256GB, no accessible internal memory

HiFiMAN founder, Fang Bian provides some information about the SuperMini and MegaMini in a letter:

Within the past two to three days, there has been some discussion online about the HIFIMAN SuperMini and MegaMini that I feel contains misinformation about the technology we use. So in the interest of clearing up any confusion and to make everyone comfortable in their consideration of our players, I offer the following clarifications.

HIFIMAN new player SuperMini and MegaMini: Single thread mode

A portable music player (PMP) is actually a mobile computer. There are a lot of portable music players that use an Android or Linux operating system. These systems are in multi-thread mode: CPU executes multiple processes or threads concurrently. Multiple threads can interfere with each other when sharing hardware resources, which creates jitter when playing music.

In computer programming, single threading is the processing of one command at a time. Instead of developing the music player software on existing Android or Linux operation system, the HIFIMAN team has developed its own embedded operating system. Specifically, HIFIMAN SuperMini and MegaMini are portable music players working in “single thread mode” most of the time; only some very small tasks such as displaying and button responses are running on multi-thread mode sometimes. More than 95% working time, they work as single threading so that their jitter level is much less than that of an Android or Linux PMP.

Reference:

https://en.wikipedia.org/wiki/Thread_(computing)

About Gapless

When a PMP is playing music as gapless, current technology has to play music and read the next track simultaneously. That way it will play the next track as soon as it finishes playing the first track. Therefore, it is a multi-threading process.

The current beta version firmware of SuperMini and MegaMini cannot support Gapless. However, the HIFIMAN team has figured out a way to support gapless playback in single thread processing. In other words, there is no more jitter generated when a HIFIMAN SuperMini or MegaMini player is working as gapless. We plan to launch it in the official version firmware before the end of the year.

Supporting Exfat SD card

The current SuperMini and MegaMini cannot directly run an Exfat format SD card however you can format it in the player and support 64, 128 and 256G SD card without any problems. We are currently working on supporting Exfat and will support it in the official version firmware later this year.

If anyone has any questions, or would like further information, please contact customerservice@HIFIMAN.com. Thank you for your support.

Best Regards,

Fang

I think that the threading argument is voodoo audiophilia. I think that most DAPs use multi-threading, as Fang Bian says: gapless has not been possible without it. I’ve heard plenty of players that sound excellent that have gapless, so this claim requires evidence. Either Fang needs to show some quantitative or qualitative data, or he needs to wait till he has it to make this claim. Until then, I’m going to disregard it as a bit of marketing parading as science.

In addition to the update about gapless, firmware and threading. The SuperMini product page gives some information about what makes the SuperMini, super, where it’s copious power comes from. The SuperMini has 8 op-amps and can output 4.2V peak voltage. The site provides a grid of headphones that normal people and crazy people might try to power using the SuperMini. I’ve recreated that grid in Table form below.

Difficulty to drive	Headphones
Drives Perfectly	Audeze LCD-2, Audio Technica A2000X Ti, Beyerdynamic DT9901, Beyerdynamic T-5p, Denon D7000, Fostex TH-900, Grado SR125/225/325, HiFiMAN Edition X, HiFiMAN HE400s, Oppo PM-1, Oppo PM-3, Sennheiser HD600/650, Sennheiser Momentum
Wide Dynamic Range	AKG K812, Audio Technica AD2000, Audio Technica W5000, HiFiMAN HE400i
Challenging	AKG K712/701/702, HiFiMAN HE1000, HiFiMAN HE560, Sennheiser HD700, Sennheiser HD800
Hard to Drive	AKG K1000, Audeze LCD-4, Beyerdynamic DT880 (250Ω), Beyerdynamic T1
1Version not specified

From the list I judge two things, the judgments on difficulty to drive were done subjectively, and the SuperMini should be able to drive anything a reasonable person throws at it. Only a crazy person would try to drive the Beyerdynamic T1, HiFiMAN HE1000 or the AKG K1000. I’ve spent a bit of time with the K1000, and it takes about 4W minimum into 32Ω to make it sing a little tune, which is more than 10 times the power output of the SuperMini. The K1000 will never be confused for a portable headphone. You can get sound out of any of these headphones with the SuperMini and the right cable, but to say that the headphones are being fully driven would be insanity—I’d have to think you are more barmy than my home country’s politics right now (I’m an American in the UK). I can power the HD600 off my laptop, but that isn’t how I’d prefer to listen to them.

Returning to the first judgment I made from the grid, I’ve listened to the HD700 for a little bit, and found it was driven just fine out of my iBasso DX50, whilst the HD600 I found more difficult. The resistance on the HD700 is only 150Ω, which is half the resistance of the HD600 and it has higher sensitivity. Similarly, I found the HD800 sounded better out of the Chord Mojo than the HD600, as while they have the same resistance, the HD800 is much more sensitive. I still, somewhat controversially among my peers, hold that the HD600 demands more than the Mojo has to offer for peak or near peak performance. Whomever was making this table has a different opinion than me, and that’s okay. Just don’t be surprised if you disagree with them on certain headphones when you try it out.

Conclusions

The HiFiMAN SuperMini is explosively powerful in balanced mode in a package smaller than a pair of Twix bars. The SuperMini plays HD600 like a child with a mallet and an old yoghurt tub, loud and enthusiastically. Most players fall over under the weight of the HD600, the SuperMini stands at attention awaiting more orders. At time of release it was one of a few balanced DAPs under $500. I can think of two others: the Lotoo PAW 5000 ($200) and the Cayin N5 ($300). The FiiO X5iii has now joined those ranks and we will review it in the near future. Whilst the SuperMini doesn’t offer all the features of those other players, it also bodyslams them from the top of the cage in terms of power, they are lucky to survive the comparison. My little brother is a big WWE fan.

The comparisons also don’t have the build quality or power of the SuperMini and they don’t come with a pair of good balanced headphones. Also, in spite of the patently false or grossly misleading 22 hour battery claim by HiFiMAN, 10 to 14 hours battery life with playback consisting of mixed lossless FLAC and HiRes content is really good. It gets about 10 hours in balanced mode while driving the HD600—this thing gives out more energy than Brawndo (democracy works 115% of the time).

On value, there isn’t another package like the SuperMini. For under $399 you won’t find a player with power enough for an HD600, and a miniature size that comes with a very good set of balanced headphones. The package is compelling and worthy of consideration, but it is not without it’s limitations.

The player is limited on features: no gapless, no USB DAC, no USB OTG, no line out, no equaliser, no gain adjustment. Some of these could be added via firmware update, and I know that gapless is already in the works. They can’t add a line out to the player, and I highly doubt that two of my favourite DAP features: USB DAC capability, and USB OTG are in the cards. The player also currently has compatibility issues with popular memory cards and doesn’t recognize cards when they are removed from the player. This problem is supposed to be fixed in the next firmware, and I really hope it is. Because of the problems with memory cards, I had to deduct half a star. I also missed  gapless. If the next firmware fixes the issue, and adds gapless playback maybe that star that half star magically appears. Pink Floyd really just isn’t right without gapless.