FiiO K1 - Portable Headphone Amplifier & DAC

MY IMPRESSIONS:

I got my K1 primarily to use with my XMG custom gaming laptop (from 2013) which has the Realtek ALC892 codec.

Honestly I wasn’t expecting much improvement but it’s definitely noticeable, the upper frequencies are sharper, mids have become silkier and low end is more refined. Overall sound resolution and musical detail has improved noticeably over my built in sound codec. I totally recommend it to anyone looking for a better sound from their laptop.

Conclusion - amazing thumb sized DAC with top notch internals for the price!

I wouldn't buy this if you think its gonna be fully compatible with your Android phone, because chances are its gonna take a lot of fiddling to get it to work. So if you want it for this purpose then look elsewhere, however some people on Head-Fi have managed to get it to work with their Nexus 6P and Galaxy S6 (using a usb hub)

In Windows its plug and play with no other drivers required.

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Lifted.

BACKGROUND

After selling my Fiio E11k and my Fiio E12, I missed having a portable amp. Not that majority of my headphones need it, but one in particular need amplification – the JVC HA-RX700. Needless to say, it’s still my favorite headphone. With a smartphone, you need to get to more than 70% of the volume to at least get some needed impact. Otherwise, they’d sound lazy. Yes, lazy. Given their low impedance, you might think they’re easy to drive. They’re not. With a DAP like the Fiio X1, they could be. But even then, I feel the need to add some amplification. Long story short, I went for the Fiio K1, and only by accident. I originally purchased a pair of Grado G-Cushions from the store. Since I didn’t like the sound signature they produced with my Grado SR80e (too treble heavy, even for me who is not treble sensitive). I decided to exchange the item and since they’re about the same price, Fiio K1 it is! Let’s begin.


ABOUT ME

I listen to almost all genres of music but my favorites are rock, blues, and jazz.

I am a music lover, not an audiophile. I need to veer away from the audiophile persona from now on. I love music more than the equipment to play music with. I recognize that decent equipment is important but decent is good enough. Expensive is not necessary. I’m not willing to go past the $100 mark for any reason. I firmly believe in the law of diminishing returns.

I believe in burn-in but it depends on the headphones or the gear. Some do not need much. Some do not need any at all.

I believe in measurements but I never relied on them. I solely rely on my ears.

I believe that blind test is the only real test, without any visual influence or biases, without placebo.

Audio nirvana for me is a state of mind, not a state of equipment.

Regardless of my beliefs, I respect all audiophiles and music lovers for their passion and dedication.


PACKAGING

Here are the pictures of the basic packaging and the DAC-amp itself. It’s a nondescript packaging and that’s everything you need for a desktop set-up. For smartphones, you will need an adapter or a micro-to-micro male OTG cable (Android). For Apple users, probably a lightning cable or adapter (I’m not familiar with Apple products. I never used them.)



SPECS AND FEATURES

For complete specs and features, please check here - http://www.fiio.net/en/products/48.


BUILD QUALITY, DESIGN AND FUNCTIONALITY

I would say pretty solid. It’s tiny but it looks good in gray. It’s not the usual Fiio-black but the look is refreshing. It’s very simple – You have the micro USB input jack on one end and the 3.5mm output jack on the other.

• For PC – It’s plug and play. Windows will take care of installing the needed drivers. You just need to set it as the default device in Control Panel > Hardware and Sound > Manage audio devices. You can also set its Properties to receive the highest bit depth and bit rate it can handle (96khz/24bit). I haven’t tried custom drivers as Windows drivers work just fine.
• For Android – You can either purchase a micro-to-micro adapter or a mini-adapter like in the picture below and you can use that for the stock cable. I’m using Stellio player for Android and it’s not finicky. It’s basically plug-and-play. After plugging, the K1 lights up and you’re good to go. A word of warning – since it’s bypassing your phone’s DAC and amplifier, it amplifies everything, including message tones and ring tones and they sound really really loud. You may want to put your phone in vibrate mode or silent mode just to protect your hearing. It disturbs you abruptly too if a message or a call comes in. It’s not a pleasant experience.

(If you’re interested on how Stellio performs, I posted my thoughts on this thread - https://www.head-fi.org/threads/best-android-music-player-app.638387/page-38#post-13911402).


SOUND

Burn-in: Honestly, I don’t think it benefits an amp the way it benefits a headphone. Nonetheless, I’m writing this after a few months of use so it’s burnt-in reasonably.

SET-UP USED:

• Lenovo K4 Note Smartphone (with Wolfson 8281 Audio Hub)
• Dolby Atmos engaged (gives a more accurate perception of soundstage (applicable only to headphones)
• Stellio music player EQ is off

Smartphones, even the best sounding ones, are inherently warm sounding or have at least a warm tilt to them. I believe this tuning is best intended for the masses and majority of people prefer this sound signature. Now the DAC in the K1 is a very capable one (Texas Instruments’ PCM5102). It’s the same DAC in the venerable Fiio E17K. The 5102 is a neutral sounding DAC, especially compared to the usual DACs in smartphones. It’s the same effect I got when comparing the sound to the Wolfson house sound of my phone. It’s noticeably leaner and you hear it immediately, there’s no second guessing. It’s akin to taking off the “fat” from your music. And the effect is a livelier, faster, and a more energetic listen.

Regarding other aspects of the sound (bass, mids, highs, soundstage, and imaging), I believe in the wisdom of our good friend Brooko. This is not affected by an amp or a DAC-amp for that matter. It’s in the headphones being used so I will not comment on those. What I will say though is an amp will most definitely have an effect on clarity, especially if the driver needs it (medium to hard-to-drive loads). If the headphone driver is moved by sufficient power, it will definitely sound not only louder, but clearer.


WHO WILL BENEFIT FROM THE K1?

First and foremost, this is intended for desktop users as the product page suggests. If you are able to use it with a phone like me, you’re in luck. If your phone is OTG capable without too much bloatware or as close to stock Android as possible, it will most likely work. Otherwise, I suggest you try before you buy.

Now let’s get one disadvantage out of the way – pops and crackles when plugging to a smartphone, especially on some quiet parts of a song, not isolated to the beginning or the end. This has been reported by several users and I have experienced the same. There are several threads addressing this issue and it’s not isolated to the K1. It’s a problem for even the higher-end DAC-amps:

• https://www.head-fi.org/threads/fiio-k1-has-problems.827559/
• https://www.head-fi.org/threads/strange-issues-with-fiio-k1-dac.843799/
• https://discussions.apple.com/thread/7685241

What might help though are the following:

• Change the audio buffer size of your phone. This feature is available in Stellio and after measuring my phone’s buffer size capability (Try this app. It works well - https://play.google.com/store/apps/details?id=com.levien.audiobuffersize&hl=en), I changed it and there is some improvement but it’s still prevalent in some songs.
• Turn off wifi or data usage. This could also be EMI. It helped to some degree but again, not on all tracks.
• Change the cable. There are higher quality micro-to-micro or lighting cables out there. I haven’t tried something expensive since I have a decent one from a local store. I imagine something like this might help but it pays if you could audition one - https://www.amazon.com/Cable-Micro-Crystal-Silver-ZY-058/dp/B00MTB760K.
• No one actually had a definitive answer and I’m not buying that it’s solely a software problem like what’s being discussed in the Apple forums. Trial and error might work or better yet, have your K1 replaced if it’s under warranty and check if it’s the same for the replacement. I don’t believe it’s defective though since it works fine with PC.

CONCLUSION

For such a tiny device, I would easily recommend the K1. Its main strengths are extreme portability and ease of use. It’s practically plug-and-play from any source and it has enough power to drive up to moderate loads. You don’t have to worry about charging batteries and it doesn’t drain too much power from the source based on personal experience.

Then again, if you’re main purpose is finesse and power to drive heavy to heavier loads, I would suggest the likes of the Fiio A3 or the A5. Comparing it directly with the A3 in high gain, the latter starts to pull away in terms of power and just sheer cleanliness of amplification.

Sonically, if you want a significant change or improvement in sound signature, you’re better off getting a DAC-amp like the K1. A pure amp like the A3 would not alter the sound signature of the source. That is innate to the source’s DAC. Using a different DAC like the K1 will give you this benefit. And it does deliver a neutral and energetic listen. For the price, it’s a total steal! Fiio has a winner in this little gem!

Happy listening, everyone!

It’s nice to be back!

INTRODUCTION

There has been a plethora of different budget friendly smart-phones, tablets, and ultra-portable laptops which may not have a lot of money invested into the audio portion of the hardware. So what do you do if you're not satisfied with the audio – even though you may love many other factors of your portable device? The solution of course is a USB DAC/amp which you can plug and play to gain an increase in sound quality. And there have been a lot of these devices released recently. So what to choose? The prices can range from under $50 to more than $250!

FiiO released the K1 ultra-portable USB DAC/amp last year, and up until now I haven't really had a chance to complete my write-up if this little device. So lets put this $40 device through its paces and see where it sits among the competition and if its worth considering.

ABOUT FiiO

By now, most Head-Fi members should know about the FiiO Electronics Company. If you don’t, here’s a very short summary.

FiiO was first founded in 2007. Their first offerings were some extremely low cost portable amplifiers – which were sometimes critiqued by some seasoned Head-Fiers as being low budget “toys”. But FiiO has spent a lot of time with the community here, and continued to listen to their potential buyers, adopt our ideas, and grow their product range. Today, their range includes DAPs, portable amps, portable dac/amps, desktop dac/amps, earphones, cables and other accessories.

FiiO’s products have followed a very simple formula since 2007 – affordable, stylish, well built, functional, measuring well, and most importantly sounding good.

DISCLAIMER

The FiiO K1 USB based portable amplifier and DAC that I’m reviewing today is supplied by FiiO completely free of charge, and is done so for the purpose of providing a review. I don't receive any payment or incentive to provide the review – but I do get to keep the sample.

I have now had the K1 for more than a year, but I don’t really use it regularly. The retail price at time of review is USD 40.

PREAMBLE - 'ABOUT ME'. (or a base-line for interpreting my thoughts and bias)


For the purposes of this review - I used the K1 mainly with my iPad Mini, my PC and old Asus laptop (as DAC).

This is a purely subjective review - my gear, my ears, and my experience. Please take it all with a grain of salt - especially if it does not match your own experience.

WHAT I WOULD LOOK FOR IN A PORTABLE DAC/AMP
This is what I would look for in a portable DAC/amp. This is useful to remember when looking at my scoring later in the review.

• Be genuinely portable => great build and small size
• Be reasonable in either battery life or drain on the host
• Be an improvement sonically over the original source
• Clean, linear signature
• Easy to use
• Able to drive both low impedance and (within reason) higher impedance cans
• Value for money

PORTABLE AMP/DACs I HAVE EXPERIENCE WITH
Previous = FiiO E7, Nuforce U-Dac3, RHA L1, Beyerdynamic A200P
Current = FiiO E17K, Q1, Q1ii, iFi Micro iDSD, IMS HVA

ULTRA PORTABLE AMP/DACs I HAVE EXPERIENCE WITH
Current = FiiO K1, i1, Cozoy Aegis, Cozoy Takt Pro

THE REVIEW

PACKAGING AND ACCESSORIES

The K1 arrived in a very basic clear plastic retail box. In the top third of the box is a small cardboard inner box which houses the included documentation, a plastic clip and a short USB to USB micro cable. The packaging is decidedly “budget”, but then again, so is the “no frills” market the K1 is aimed at.


Probably the only thing I thought was missing was a short micro-USB to micro-USB cable, but as you'll see later in the review (connectivity options), you'll appreciate why I no longer see this as necessary.

TECHNICAL SPECIFICATIONS
For this section I've included comparative data on FiiO's older original Q1 which currently retails for ~USD 55.00. Its also a DAC/amp (not ultra portable – but necessary for comparison being similarly priced.)

BUILD
The K1 is rectangular shaped with nicely rounded edges on the main body. The main body has a subtle ridged design which makes it easy to grip. The top panel houses the 3.5mm headphone out and a blue LED light which glows when operating. The bottom panel houses the USB socket. Both sides have a groove to house the removable plastic clip.

Small and neatly finished	The removable plastic clip

Internally the K1 uses a Savitech SA9023A USB receiver combined with TI's high fidelity low noise PCM5102 DAC chip. Amplification is undertaken by the TPA61332A on-board amplifier.

Tiny compared to the iPhone and FiiO Q1ii	Blue LED when in operation

HEAT AND POWER

The K1 doesn't heat up at all, and is quite cool to the touch even after a few hours playing.

In terms of power output, the specs say that it'll put the following output into these loads:
Into 16 ohms = 75 mW
Into 32 ohms = 35 mW

FiiO suggests headphones with impedance up to 150 ohms max – mainly due to the relatively weak amplification. My first task (using my old ASUS eeePC and work MS Surface laptops) was to find out how much gain the K1 would deliver over and above the on-board sound-cards. So I simply used the quite demanding MEE Pinnacle P1 (50 ohm / 96 dB sensitivity), and took a couple of measurements with my SPL meter.

With my Asus eeePC running either Linux or Windows, the internal sound-card. was weaker than the K1 by around 14 dB when played at full volume (with the internal sound-card only managing a paltry 84 dB at max volume). With my work laptop (an MS Surface) the internal sound-card. was a lot closer to the K1's output with only about 4 dB difference (in favour of the K1).

Easily handled the MS Pro and HD630VB	Underpowered with more demanding headphones

In the case of the P1, I was able to get adequate volume from the K1 (with both Surface and eeePC) at a volume level of around 25-30% for my usual ~ 65-75 dB listening level. I also tried my 320 ohm VE Zen2, my MS Pro and HD630VB, and everything I threw at it seemed to be handled pretty well.

When it came to the 300 ohm Senn HD600 or HD800S, while I could get the volume loud enough, they were clearly being underpowered (loss of bass and general dynamics). It wasn't unexpected, and I have to admit FiiO got their range right here. If you stick with IEMs and relatively easy to drive dynamics, you'll have no issues.

SONIC PERFORMANCE

Preface
I’m going to preface this section with a little critique I received a while ago (by PM), and my answer to it – so that you can understand why I don’t comment on some things, and why I do comment on others. I was told my review on another amp was poor because I didn’t include sections on bass, mid-range, treble, sound-stage, imaging etc – yet referred to an amp as warm, full, or lean.

Now I can understand the reference to warm / full / lean – as they are very subjective terms, and whilst I’d like to avoid their use, they are invaluable to convey true meaning. Comparing my NFB-12 to the Aune X1S for example – the Audio-gd does sound richer and warmer. It’s the nature of the DAC which is used.

But I choose not to comment on bass, mids, treble, and most definitely not sound-stage – simply because when we are talking about a DAC/amp – IMO they shouldn’t be discussed. An DACs job is to decode the signal in as linear fashion as possible, and the amp’s job is to amplify the signal with as low distortion as possible. Basically you should be aiming to output as linear signal as possible. If the device is doing its job properly, there is no effect on bass, mids, or treble – except if hardware boost is concerned. And IME an amp does not affect sound-stage (unless there is DSP or cross-feed in play) – that is solely the realm of the transducers and the actual recording.

So we have that out of the way how does the K1 perform sonically?

Tonality
For those interested, FiiO does show graphs of the K1 under load, and it is very linear from 20 Hz – 20 kHz, with a very gradual drop off in the upper treble (around 0.2 dB) with the main part of this drop occurring from 10-20 kHz. At that very slight level, we won't really hear it. I could have measured this myself – but in this case I know FiiO's Audio Precision set-up is a lot better than my hobbyist gear.

FiiO’s Measurement	Small device, clean sound

I listened and compared it to the E17K (one of the most linear devices I own). In subjective comparison, the K1 is very similar with perhaps a hint of warmth / fuller tonality than the E17K. So what does this tell us? Simply that the K1 supplies reasonably linear, and very clean output. Purely subjectively, it sounds pretty neutral and to my ears, ever so slightly on the warm side of neutral. It does have a reasonably clean background which creates a good sense / perception of space.

Format Support
I've tested with PCM up to 96/24 and the K1 has had no issues natively decoding.

In Comparison To The On-board Sound-cards
With the Asus eeePC, its an older model, and the sound-card was never very good on it. Its on the noisy side, and will regularly pop or cut-out. With the K1, the difference was easily noticeable – sound was a lot more consistent, and there was a sense of more space and separation of instruments with the test tracks I used. Sonically the K1 also delivered a richer overall tonality, and gave a sense of higher resolution.

With the Surface, the two were a lot closer, and the differences far smaller. Overall the K1 still gave the sense of a slight improvement, but it wasn't as noticeable as with the eeePC. This is all very subjective, and whilst I'd relatively easily pick the Asus from the K1 in a blind test, I do feel the Surface might be a lot harder (and fear that maybe the differences are purely imagined on my part).

CONNECTIVITY

Laptops / PCs

Testing with a variety of sources	Plug and play with the Surface

Using both the two laptops, and also my desktop, the K1 connected and set-up without any need for additional drivers (both under Linux and Windows). As FiiO states, this is simply a plug-and-play exercise. And that makes it ideal for something like a work machine – especially if you're hamstrung by an IT department who don't like you installing things like extra drivers.

Tablets
I'm guessing you'll have no issues with windows based tablets, and unfortunately I couldn't test it on an Android based device. I do have an iPad Mini I use regularly though. And with a camera connection kit, the K1 was recognised straight away and I was up and playing very easily. Was it an improvement over the iPad's default on-board sound? That's a really hard one to answer. Again it was a slight increase in overall volume, but after volume matching the two were really close (the iOS devices have always been very linear). Once I'd volume matched properly, there seemed to be very little between the two. But it was gratifying to have the option (with the camera kit). I did try some other lightning to micro-USB cables, but the only that would work was the L19 cable.

No issues with the iPad	And also with the iPhone (and camera kit)

Smart-phones
I first tried my wife's Galaxy, but the K1 wasn't going to play ball no matter what I did. I also tried FiiO's own X5iii and X7ii (both being Android devices) – their Q1ii managed to work with both recently so I was hopeful but unfortunately disappointed. I think with Android you are always going to be a bit hit and miss.

With my iPhone SE, I was originally disappointed – none of the cables seemed to work (including FiiO's cable included with the Q1ii). The L19 did work though, and so did the camera connection kit. Again the sonic differences with iPhone SE were slight (the SE seemed ever so slightly brighter without the K1) but it was practically unnoticeable (subjectively). While it was nice to have the option, its not one I'd probably feel the need to use.

EMI / RFI
Thankfully there hasn't been any issues, and that’s despite having the iPhone and iPad streaming (there was no sync issues either – video vs audio). And in this regard, the K1 does seem to perform really well.

Power draw
Because it doesn't have its own battery / power source, this is always going to be somewhat of an issue with a device designed to be used portably. With the K1, my testing seemed to indicate that for laptops you're not going to really notice the power draw (the K1 is sipping rather than gulping). This was similar with the much larger battery on the iPad Mini its hardly noticeable. With the iPhone's smaller battery, I'd estimate that battery usage might have increased by around 10% using the K1, but again that’s not what I'd call a huge issue (for me anyway). YMMV.

COMPARISON WITH OTHER DEVICES

I thought at this stage it would be a good idea to try and compare the K1 with some alternatives. My prerequisite was that the comparable units should all be portable DAC/amp devices which would work with my iPhone, laptop and tablet – so I’ve used a mix of similarly price amp/dacs, and somewhat more expensive ultra-portable USB devices from Cozoy.

I tested the K1 against my FiiO Q1 original (currently USD 55), FiiO E17K and FiiO Q1ii (both USD 99), Cozoy Aegis (~ USD 299) and Cozoy Takt Pro (~ USD 289). For testing I’ve used my iPhone SE, headphone out of the device in question, and my Sennheiser HD630VB to evaluate. All devices were volume matched with my SPL meter at 1 kHz with a constant test tone.

FiiO K1 (~USD 40) vs FiiO Q1 original (~USD 55)
These are both in the same price bracket. The K1 is the ultra portable, while the Q1 is the portable. Both have FiiO's very good build. The K1 has the benefit of size (you'll hardly notice it is there) – the Q1 has the benefit of features (bass boost, gain, volume pot, power output, can be used as stand-alone amp, and own battery). Both are immediately recognised by my Linux set-ups, both work with the iPhone and iPad, and both also work as driver-less solutions to my two Windows based laptops.

In terms of sound, the Q1 subjectively is very slightly richer in tonality with a better (darker) background and more sense of instrument separation. Both are an improvement on the eeePC's default sound-card. The power output is a huge bonus too, because with the Q1 you can also drive an HD600 to respectable levels of volume and quality.

Really this one is a no-brainer for my preferences. Unless you need the ultra-portability, the Q1 original is the far better device (IMO).

K1 vs Q1 original	K1 vs E17K

K1 (~USD 40) vs FiiO E17K (~USD 99)
I should preface this to say that the E17K is still my favourite Swiss army knife for a portable amplifier. I terms of price bracket, the E17K is more than double the price of the K1, and really they are targeted for different uses. Again the K1 is the ultra portable, while the E17K is the portable. Both again have rock solid build quality. The K1 has the benefit of size (you'll hardly notice it is there) – the E17K has the benefit of features (tone controls, gain, volume pot, power output, can be used as stand-alone amp, and own battery). Both are immediately recognised by my Linux set-ups, both work with the iPhone and iPad, and both also work as driver-less solutions to my two Windows based laptops.

In terms of sound, the E17K is subjectively the more linear of the two devices, and with its easy to use tone controls, you can make it warmer or brighter with any ear/head-phone. Again to me it has a better noise floor and more sense of instrument separation. Both are an improvement on the eeePC's default sound-card. The extra power output of the E17K is a bonus allowing more versatility in head-phone choice.

Given my choice, I would personally save for longer and buy the E17K. Its feature set provides far better value for money. But we are talking about very different devices here, and if $40 is all you have, the the K1 still provides an incremental gain for comparatively little monetary outlay.

FiiO K1 (~USD 40) vs FiiO Q1ii (~USD 99)
Again the Q1ii is in a different price bracket, but I consider the comparison valid, simply because they can both be considered portable enough for use with smart-phone or lap-top. The K1 is the ultra portable, while the Q1ii is the portable. Both are built incredibly well. The K1 again has the micro size, while the Q1ii has the benefit of features (bass boost, gain, volume pot, power output, balanced out, plays more formats (including DSD), can be used as stand-alone amp, and own battery). Both are immediately recognised by my Linux set-ups, both work with the iPhone and iPad, and the Q1ii works as driver-less solution on the Win10 Surface, but requires a driver for the Win7 eeePC.

In terms of sound, the Q1ii subjectively is very slightly richer in tonality with a better (darker) background and more sense of instrument separation. Both are an improvement on the eeePC's default sound-card. The power output again is a factor, and if DSD is your thing, it will offer more options. The one draw-back the Q1ii has is an issue with EMI/RFI causing static feedback with the iPhone (I haven't noticed it with the laptops).

K1 vs Q1ii	K1 vs Cozoy Aegis and Takt Pro

FiiO K1 (~USD 40) vs Cozoy Aegis (~USD 299)
Now we move into the ultra-portable vs ultra-portable, but this time we're talking a whopping difference in price. Both have a fantastic build quality, but the Aegis does come with more accessories (cables) and seems to have better connectivity options with both Android and iOS (you never have to jump through hoops - it just connects). The Aegis does have resolution up to 24/192. With Win 10 it is plug and play, but with Win 7 you have to load drivers.

Before we get to sound there are a couple of other factors to consider. The Aegis does get a little warm (it is more powerful than the K1 and does have a higher gain), but has a consequently much higher draw power on the source (it will drain an iPhone battery over the course of 4-5 hours). Because the gain is set very high, you also need additional volume control (so with iOS this means using an app with a pre-gain control). Both are fairly big drawbacks unfortunately.

Sonically the two are also quite different. The Aegis has more richness to its tonality, but also seems to have more overall resolution (ability to really bring out high level detail). The K1 is still very good, but the Aegis does seem to take things to a slightly higher level.

So in terms of overall use, what are my thoughts? In this one (for me with iOS, Linux and Windows use) the K1 wins (YMMV with Android). It is cheaper, is still very good sonically, and doesn't have the issues with power draw or volume control. You won't have the same power output (higher gain), but for a device to be good, it has to be versatile, and in this case the K1 delivers a little better.

FiiO K1 (~USD 40) vs Cozoy Takt Pro (~USD 289)
Another ultra-portable vs ultra-portable, and I left this one to last because I've only had the Takt Pro for a couple of weeks. There is another big price difference, but this time the Takt Pro has a few more features up its sleeves. The Takt Pro comes with more accessories (cable choices), and again has the better connectivity options with Android and iOS (you never have to jump through hoops - it just connects). The Takt Pro has resolution capability up to 32/384 and also DSD. With Win 10 it is plug and play, but with Win 7 you have to load drivers.

In terms of build, the Takt Pro is actually even smaller than the K1, and has the added benefit of on device volume and playback control. This works with iOS, Windows and Linux – and is implemented really well. Unfortunately Cozoy don't advise actual power output, just voltage – but using a calculator I was able to determine that Cozoy's 1.5V RMS equates to about 25-30% more power than FiiO's 3.25 Vp-p. In terms of power draw, I haven't been able to calculate this fully – but it appears that the Takt Pro does draw a little more power than the K1 (expected with the power output), but doesn't seem as hungry as the Aegis. In terms of actual real-world power output, the Takt Pro does a fairly reasonable job with the HD600 where the K1 struggles.

Sonically the two are again quite different. The Takt Pro has more richness and depth to its tonality, and definitely seems to have more overall resolution (ability to really bring out high level detail). The K1 is still very good, but the Takt Pro does seem to take things to a higher level, and enough that I'm quite blown away at how good this tiny device sounds.

So again in terms of overall use, what are my personal thoughts? In this one (for me with iOS, Linux and Windows use) I'd actually be more inclined to save for the Takt Pro (I really like it). If it doesn't fit your budget though the K1 is still an improvement on a lot of basic audio set-ups.

VALUE

This one is probably an easier one to call than most. The K1 delivers good value for a no frills audio device. It does what it claims to (an increase in audio quality), and does it well. Are there better value options out there? Yes – given the choice, I'd still plug for the Q1 original being a better overall option, but it doesn't stop the K1 being a pretty good device for very little outlay.

FIIO K1 – SUMMARY

The K1 is a bit of an enigma to me. At its heart it is a very good value (only $40!), well built device which does very little wrong, and does deliver a genuinely better audio performance than some of the cheaper on-board solutions in cheaper laptops. It is definitely an improvement on my old Asus eeePC.

Its also pretty much a driver-less solution which is agnostic of device, although the 3 Android devices I tried to test with simply would not connect. So with Android I'd advise a little caution (check reviews and see if anyone else has had success). With Windows the connection is simple and painless. With iOS, if you have a camera connection cable, you're all set.

It is relatively weak on power (only 1.2 dB overall gain), but the K1 was never really about power and more about quality anyway. It offers a pretty neutral / linear overall tonality, but maybe with the faintest hint of warmth. Resolution and noise floor seems decent – especially at this money, and there seems to be no issues with EMI/RFI.

For its asking price, its a decent offering – I just personally think the Q1 original gives you a lot more options for a similar price. And if anyone is actually thinking of using a K1 + A1 combo, just get the Q1. It is better value.

This was always going to be a hard one to rank – so I went back to my original thoughts on requirements for an ultra-portable, and tried to apply an objective rating (see table below). The end result – good value and sonically an improvement. A good solution for someone just getting into audiophilia.

I just want to close with thanking Sunny and the team at FiiO for arranging the review sample.

Scoring Chart

USB Ultra-Portable DAC/amp	FiiO K1			(out of 10)
	My Score	Out Of	Weighting	Weighted Score
Accessories	5	10	2.50%	0.125
Build and Design	9	10	5.00%	0.45
Power Draw	9	10	7.50%	0.675
Output Power	6	10	7.50%	0.45
Portability	10	10	7.50%	0.75
Overall Sound Quality	6	10	35.00%	0.60
Driver-less Solution	10	10	7.5%	0.75
Connectivity options	6	10	7.50%	0.45
Music Format Support	6	10	2.50%	0.15
On Device Controls	0	10	2.50%	0.00
Noise (EMI/RFI)	10	10	5.00%	0.5
Value	9	10	10.00%	0.9
TOTALS	86	120	100.00%	7.30

So first of all, since all reviews are subjective, I will gonna state some stuff about me first before I go review the Product.

My Background:
I am a amateur bassist. I am currently doing live mixing at church. I am someone on a budget so don't expect reviews about High-End Gear.

My Music Preference:
Rock, Jazz, J-Pop, J-Rock, K-Pop, EDM, Heavy Metal, Acoustic Music

My Preferred Sound signature:
I prefer some sort of bass boost, but not up to the level where the music sounds muddy. I would rather listen to no bass than listen to muddy bass. But my ideal bass boost is the bass boost where the Bass Guitar is kind of Forward. I like the mids to be flat, not forward, and not Recessed.. I like some treble boost as well but just quite the few steps before becoming sibilant. I like Female vocals to be lushy and quite edgy, especially to the high pitched ones. I like male vocals to be just natural sounding. I like to hear soundstage that is not quite spacious, and also not quite intimate, but I would rather like to listen to the details mushed in my ears rather than listening to music with a sense of space on everything like speakers. I do not care to imaging that much but it is nice to have.

My Testing Devices:
Pioneer HTZ-424DVD(Home Theater System)
Audio Technica ATH-CLR100(In ear Monitor)
Philips SHP2000(Semi Open Headphones, w/Mods)
iCore WavePods(Closed On-Ear Headphones)

Playback Devices:
Dell Latitude E6400
Dell XPS L702x
Neo N81(in Both Android and Windows OS)

Music Sources:
Youtube
Spotify
CD Files ripped in wav format.

Player of Choice:
MediaMonkey using WASAPI Output, Stock Android Music Player, Youtube, Spotify
 
Intro:
I bought the Fiio K1 out of curiosity because of the reviews from Head-Fi, Z Reviews, and Youtube reviews(So technically, I am quite the Average Consumer, not quite the Audiophile yet, but is starting to enter to the world of such). I also bought it because I am curious on having a DAC/Amp. As an Average consumer, I quite find the Device to be worth the purchase. Even if this is my First DAC/Amp, and my Only DAC/Amp, I know the Fiio K1 because I always use the device.
 
Social Experiments as a Review:

I tested my Little Sisters using the the Track Let it Go-Demi Lovato using Spotify,and using iCore Wavepods and used it to compare my E6400's onboard audio against my Fiio K1. I experimented them with a Blind A/B Test. They kind of struggled which is which, but they have heard some subtle difference.
 
I tested my friend to do a blind A/B test as well, I forgot the Track that I used. He didn't noticed the Difference between teh E6400's onboard audio against my Fiio K1.
 
I experimented using the K1 as A DAC for the Speakers. I used my Dell Latitude E6400 plugged into the Fiio K1 plugged into Pioneer HTZ-424DVD via AUX connection. I played a random jazz music on youtube, and the audio sounds clean and the layering works well. The sound's cleanliness reminds me of Some Background Music played at Hotel rooms with their speaker systems. 
 
Personal Experiences as a Review:
In my personal experience, I noticed that my Fiio K1 can push my SHP2000 to the louder volume compared to the E6400's. And the Fiio K1 does improve the soundstage and imaging. My onboard audio sound feels like the sound is always from the headphone driver, especially to my Audio Technica IEMs.
 
Compared to the onboard audio of my friend's HP Laptop, the difference between the K1's output is night and day with the K1 having the Favor. So if you are thinking of replacing your onboard audio for an improvement for the cheap price, you know that this little K1 could be your sound card replacement.
 
One thing to note that the DAC/Amp could get hot when you use it on hot places. Once the Fiio K1 Gets hot, they make your headphones and earphones become Needles. The sound feels quite piercing to the ear when it gets hot(This will serve as a warning to those who are wanting to get it but they live in Hot Areas).

Also, a thing to note is that the USB port affects the Sound of the DAC/Amplifier. I tested it on one of my L702x's USB 2.0 Port. It makes me wonder what happened because when I plugged it there, and used my SHP2000s. The Bass becomes intense, like the air is slapping your ears and it hurts. I plugged it into my L702x's USB 3.0 Port and The bass of SHP2000 became normal, like what I usually listen to my E6400 Laptop+the Fiio K1. On my Neo N81(in both windows mode and android mode), The Fiio K1 retains the Sound Quality, but just a little bit lower in terms of Max Volume compared to my E6400 and l702x.
 
One thing to note also, since it is not battery powered, like the other Portable DAC/Amps, it quite eats power from my Laptops to make it sustain its function. At least no charging required on this Portable DAC/Amp.
 
When I use my Audio Technica ATH-CLR100, together with the Fiio K1, I noticed that there is hissing on the IEM but the hissing is not that quite noticeable unless you focus on listening to the hiss, or you replugged the IEM back to the K1(This will serve as a warning to those who are conscious about hissing). I tried to max the volume of the K1, and luckily, the Hissing isn't amplified. Maybe it is more on the IEM itself
 
I tried my Android Lollipop Phone and it can't detect the DAC/Amp, so for short, it might not be working on all Android Devices.
 

Conclusion:
Despite the flaws that I pointed at specific scenarios, I still find my Fiio K1 to be a good Portable DAC/Amp. Solid build, Solid sound, Cheap Price. This will be the Average Consumer's Endgame DAC/Amp(Unless they want to enter to the world of much Higher Fidelity Audio)

Portable media, whether it be on your mobile phone via streaming services or on a dedicated media player is becoming more and more common these days. Cheap data plans and the plummeting prices of small data storage makes the ability to carry around your music library easier than ever before.
 
Fiio has capitalised on this growing market. Becoming one of the most well known brands, and holding the largest market share with their ever expanding product line.
 
The Fiio K1, weighing in at a staggeringly light 11.3 grams is one of the newest additions to Fiio’s lineup of portable DAC/ Amplifiers. In this review I will be discussing the audience this product is aimed at, the usability and quality of the DAC/ Amplifier, as well as its performance in terms of sound quality.
 
At the time of this review the Fiio K1 can be had on Amazon for a measly $39.99 USD. This is by no means a hard task to save for. Hitting well above their price range seems to be a trend that Fiio is continuing to follow. Opening the world of great sounding audio to the masses without the stigma of spending thousands on portable music devices.
 

 
Just a disclaimer: This product was sent to me by Fiio to conduct an unbiased review. I have not been given any information to convey from them and will give my honest personal opinion.
 
Packaging:
 
The K1 DAC/ Amp comes in simple plastic packaging. The top half of which is see through so you can marvel at it’s size without having to open it.
 
What comes inside the box is pretty minimal. You simply get a 16cm usb to micro usb cord and the K1 itself with an attached clear plastic clip. There is also some documentation, but I never read that.
 
I find the inclusion of the clip quite strange but I’ll discuss why later on.
 

 
Build Quality/ Design:
 
The materials used in the K1 are very decent in my opinion. The body is an anodised aluminium and it is capped by two grey plastic ends. The clip is a clear brittle plastic. It’s holding onto ridges on both sides of the K1’s body and can be slid up and down as well as removed altogether.
 
The micro usb slot is recessed slightly in the body, and the 3.5mm jack on the opposite end is metal which I like.
 
As I mentioned at the beginning of this review. The unit itself is only 11.3 grams. It is around 10 grams without the plastic clip attached. It measures in at 50mm*20.5mm*8mm so about the size of a standard usb drive.
 
Everything looks very tidy and clean. Fiio have done a good job with the design of this device and the way it’s put together.
 

 
Target Audience/ Compatibility:
 
Now who is this device aimed at. It’s a relatively cheap device with a miniature footprint and a shirt clip. You’d assume it is for portable use. The issue is the K1 is only compatible with SOME portable mobile devices.
 
I’ve read comments on Amazon where the K1 works flawlessly with the Nexus 6P. I tried it with my Samsung Note 5 but the first 4 attempts failed. I also tried it 3 times with the Asus Zenfone 2. Strangely the first time everything worked correctly with no extra apps installed. But I tried again an hour later and it no longer worked, it didn’t even have the blue light to indicate it was on (super weird).
 
Android was supposed to support usb audio from Lollipop onwards. However from many comments online the K1 only seems to work on a select number of devices. I don’t blame Fiio for this as the Android usb DAC thread clearly shows the total disarray of device compatibility with many other usb dac solutions. Fiio have clearly marketed the K1 as a computer only device as to not give hope to those thinking of buying for their mobiles.
 
Just letting Apple users know. The K1 should work with your mobile devices. However Fiio suggest pairing the two with the camera cable adapter.
 
Out of the many usb dac compatible apps on Android the only one that seemed to work with my Note 5 was Usb Audio Player PRO. This in turn for me makes the inclusion of the plastic shirt clip a bit redundant since many portable devices are simply not supported for the K1.
 
(Sorry about that rant. I was trying to get this thing to work with my phone for the longest time.)
 
Fiio is targeting this to the people with computers and laptops. Devices that don’t always put sound as high of a priority as they should.
 
I tested the Fiio K1 with a 2014 Macbook Air running the latest version of El Capitan as well as my desktop running the latest version of Windows 10.
 
Both computers detected and worked with the K1 immediately without any issues. Since the DAC is only 24 bit. This means that no special drivers need to be installed. It makes it super easy to get going. Just make sure to choose the correct output device for sound on both platforms and you’re golden.
 
Sound Quality:
 
I find the differences in DACs past a certain price range are pretty hard to discern. However the amplifier is usually more noticeable in setups.
 
Frequency Response
 
In my testing with various earphones and headphones I found the K1 to be bright. It extended the highs quite a bit, with my IEM’s the extension even sounded a bit distorted. Soundstage increased by a small margin with my testing as well.
 
Bass was cleaned up and you get less boomy and more tightness and punch. This may be desirable or not depending on your listening style. I would say it makes electronic music a little fatiguing to listen to.
 
Below are the measurement charts from Fiio’s website:
 


 
Power output
 
The packaging suggests the K1 can power anything up to a 100Ohm impedance. However in my testing it seemed to drive my HD800’s just fine. As I mentioned above it is a brighter amp so it wasn’t the best pairing. Also soundstage actually lost out a little bit with this combo.
 
The K1 also managed to drive the Alpha Primes alright. Was at a listenable volume at 75% and 80% with onboard. Very similar on the laptop as well.
 
I will note though that the headphones above could both have done with a bit more power output. Listenable volume is one thing, but the current required for good sounding audio reproduction is another. I don't think you should try listening to any high power drawing headphones on this little device.
 
When it comes to IEM’s when hooked up to a desktop it drove at decently high volume at around 15% digital volume. Compared to the onboard soundcard which was around 19%
 
I also tested everything again on my macbook. The difference in power was about the same. The macbook would be at 20-25% depending on the IEM and with the K1 it would be 15-20%
 
Noise Floor
 
When it comes to adding a DAC or Amplifier to your setup. Whether it be on your mobile, portable player or computer. You would expect or hope to get a lower noise floor than your original device.
 
I was a little disappointed to hear a hiss when plugging in the K1. I tried multiple USB ports all had an audible hiss on IEM’s. I would say the hiss is about 3 times louder than the standard output on the macbook. Even on my desktops front side audio I actually heard no hiss.
 
For even slightly higher impedance headphones you will not have to worry about this. But I think for the size and portability of this device, the hiss might be annoying for some people that primarily use earphones.
 
Bitrate
 
Like most DACs these days the K1 can handle up to 24 bit decoding. However due to the SNR on their specs page of around 100dB you will only discern about 16 bits of information if you have perfect hearing anyway
 
Conclusion:
 
My opinion on the K1 is both good and bad. The audience for this device is very narrow it seems due to some shortcomings and flaws, some of which are not the fault of Fiio.
 
Firstly due to the Android operating system not being coherent across the device range (unlike Apple devices and IOS) the compatibility with Android is hit and miss. This rules out a lot of people who want to use this device for on the go portable use. I managed to use Usb Audio Player Pro, however I am not willing to spend that amount of money just for an app (A quarter of the price of the K1).
 
This narrows down the users of the K1 to the office laptop/ desktop market. Most of these computers have crappy sound cards, fair enough. However due to the K1’s hiss some will not want to use IEM’s meaning the majority might opt for headphones instead.
 
Here is where my opinion comes in. Why would you spend $39 on a DAC/ Amp that only increases your power output by about 5%. Many power hungry headphones tend to struggle a bit with the current provided by the K1 (including the Alpha Dog). For an extra $20 you can get the Fiio Q1 which has considerably more current output at lower impedance and is more suited to headphones.
 
Don’t get me wrong. With some bassy IEM’s the K1 really does tame the boominess and give more of a tight punch with decent clarity. However I just can’t get over the distortion heard in exchange for that clarity, it sounds a bit echoy like listening to music through a concrete pipe. This just isn’t as evident on headphones. The hiss is also gone on most headphones. All of this pushes the K1 to be a transportable headphone amp. However it’s bigger brother (that doesn’t cost that much more) just does the job better.
 
Sorry to give a negative conclusion but the K1 has left me confused. With a little more power and a cleaner output I think it would be one heck of a product.

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I would like to Thank FiiO for providing me with a review sample in exchange for my honest opinion.
 
Manufacturer website: http://www.fiio.net/en/products/48

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Is there an audio product that FiiO doesn't have in their portfolio?  How about a micro-sized USB DAC/amp?  Well, now they got one of those too, a brand new FiiO K1 usb dac/headphone amp.  This is not the first thumb-drive size usb dac/amp I've tested, but certainly the first one I have seen at such low price.  When it comes to FiiO, making more affordable products doesn't mean sacrificing quality, and K1 is no exception.  So let's take a closer look to see what I have found.
 
Unboxing and accessories.
 
FiiO took a different approach with K1 where using a clear plastic packaging allows you to gaze right through the box to see the exact size, shape, and ridged surface of K1.  You no longer have to guess what's inside or try to figure out if the image printed on the cover is up to scale.
 
Included accessories are a short usb to micro-usb cable, warranty and user’s guide, and a removable plastic clip.  There is no battery since K1 works right off usb bus power.  Also, I'm not sure if plastic clip was really necessary.  Coincidentally, I'm reviewing their new small M3 audio player, and have the opposite comment where I would rather see a removable clip on M3 rather than K1.  I mean, it's a removable clip after all, and can be easily detached, but I don't see the point of it.
 
 

 
The clip.
 
 
 
Design.
 
Weighting only 10g (w/o a clip) and with dimensions of 50mm x 20mm x 8mm, this is one tiny lightweight device dressed in all metal sandblasted titanium color shell with a ridged surface.  One side of K1 has micro-usb connector and two small pentalobe (iphone style) screws.  The other side has 3.5mm TRS headphone output and led to indicate the power.
 
Under the hood you will find TI PCM5102 DAC which supports audio up to 24bit/96kHz, TPA61332A driver, and Savitech SA9023A usb receiver to decode usb audio.  It paired up and worked flawless with my laptop, but it didn't work with my smartphone (neither Note 4 nor Galaxy S5).  That's probably the only real downside for me since I know about another usb dac with the same usb receiver where according to people's comments it's capable of being connected to a smartphone through usb-otg port.  I know it's a bargain, but considering small footprint and sound improvement over my laptop stock sound chip, I think it would have been an ultimate gadget if it would support smartphones as well.
 

 
 
USB DAC connection.
 
 
 
Current draw (40mA idle, 50mA under a full load).
 
 
 
Sound impression and comparison to other USB DACs.
 
FiiO K1 has a dynamic sound with a nice separation/layering and a decent resolution, excellent soundstage expansion with a very impressive width.  The sound is very crisp/detailed, and has a good top/bottom extension.
 
In comparison to $40 K1, here is how other portable usb dac/amps stack up:
 
HRT dSP ($70) - in comparison to K1, the sound is flatter, not as dynamic, soundstage  shrinks in width, and you lose some transparency and resolution.
 
Astrapi ($130) - in comparison to K1, Astrapi has a very similar dynamic sound, similar layering/separation, soundstage is as wide but has a little more depth/height, overall sound is a little bit thinner, doesn't have as much body as K1, and sub-bass doesn't go as deep.
 
DragonFly 1.2 ($148) - K1 has a touch wider staging, a little brighter, crispier sound, while DF is smoother with more body, deeper bass.  Similar retrieval of details, and a similar dynamic sound.
 
FULLA ($79) - FULLA is a little smoother, has more body, has a similar soundstage width and more depth/height.  Overall sound is tighter and has more transparency in comparison to K1.
 
Despite its spec suggesting to be able to drive up to 100 ohm headphones with a power of > 75W (16 ohm load), I had no issues driving my demanding 320 ohm VE ZEN (very dynamic, layered sound), though trying 470 ohm ATH-R70x wasn't as good (sound was a bit dull and flat).  It definitely was a huge improvement over my laptop HO, pairing up great with most of my headphones and providing a noticeable expansion in soundstage width, making sound crispier, more detailed, and more transparent.  As a matter of fact, I fount it to pair up better with neutral and warmer headphones, while sounding a bit thin and peaky with some bright and analytical sound signatures.
 
 
 
Conclusion.
 
It looks like FiiO continues to push the envelope of price/performance ratio, and K1 is another prime example of that.  Relative to my laptop (a few year old ThinkPad T430s), sound improvement was noticeable, though I don't guarantee it will be on the same level of improvement with every computer or laptop.  What's important here is an increase in power to be able to drive more demanding headphones with ease, and also to be able to enjoy your efficient headphones with a sound improvement as well.  I would have loved to see USB-OTG support to be able to connect K1 to my Android smartphone (can't speak for iPhone).  I hope that FiiO will consider supporting this in the future.  Other than that, this is one cool little audio gadget for under $40.