Calyx Audio PaT Portable USB DAC and Headphone Amplifier - Gold - Reviews
Pros: Sound really good - low power draw - light and sturdy - plug and play - OTG cable included
Cons: Buttons do no work on android - can get some minor clicks with FLAC at highest compression (lvl 8)
I have a love/hate relationship with my Fiio X1ii. On one hand, it introduced me to the world of quality audio, teaching me that not everything is about bass and the importance of clarity an restraint. On the other hand, it's a buggy, slow mess of a player that comes with a huge side order of frustration. After battling with over the last couple of years I gave up and decided to use my phone for music duties.
Yeah, phone audio is rubbish, however the interface is great. I decided to go for a DAC/AMP combo and call it a day.
Looking around, I saw the Calyx PaT was on special ay $76 down from $130 (those are Australian dollars by the way) so I pulled the trigger.
To be honest, I wasn't expecting much at the price and size. If it got anywhere close to the X1ii in terms of sound quality I would've been happy.
Well, it does sound a bit like my X1ii, except a bit better!

Good. A well machined piece of aluminium (I assume it's aluminium) with a soft rubber backing.

It's light and it feels like it could take a beating.

This thing is tiny. Only a tad bigger than my thumb a weighing about 20g. Theres no need for mounting kits and such. You can just leave it dangling if you want or grip it under your phone with your hand.

I've used the Calyx PaT on both my android phone (Version 7 - Nougat) and my PC (Windows 10) and it worked seamlessly with no driver required. Just plug and play.
The unit has 5 control buttons which work just fine on Windows (and apparently with iOS devices) but no luck with Android.

Be aware that this unit only does a max of 48khz at 16-bit. No 96khz 24-bit for you!
Also, one thing I've found is that FLAC produce some clicks and pops. May it's because I'm using level 8 compression.
I converted my files to WAV and the issue disappeared.
If I remember, I'll re-encode them as FLAC level 4 and see if the issue pops up again and will update this.

UPDATE: I lowered the compression level to 4 and now works beautifully.

Power Draw:
The unit is unpowered and relies on USB to function. Fortunately it just sips power.
Even With my old Galaxy S4 it didn't make much of a dent to its already disastrous battery life. With my new Huawei Y7, I listen to music for more than 11 hours a day and by the end I still have over 40% power left. YMMV of course.

The first thing that hit me was the openness of the sound. Unlike my phone which sounded like everything was being played inside a phone booth, the Calyx PaT opened the stage and gives a lot more depth to the sound positioning.
Don't ask me how or why that is, but it's there. It just sounds so clean and full bodied!

My daily headphone is the MSR7. As most of you would know, it's a bit anaemic in the bass department. The Clayx PaT gives it a warmness and oomph that complements it beautifully.
Treble appears smoother too, with some of the harshness in the higher regions toned down providing a less fatiguing listening experience.
Compared to my Fiio X1ii, the sound is very similar except that there's more impact down the low end. There's a good amount of both quantity and quality.
Treble sounds a bit smoother. It could be placebo effect, but the highs and mids do appear to sound a tad richer and better separated.

I woukd say the Calyx PaT edges out my old X1ii and decimates my two phones in terms of sound quality.

Final Thoughts:
So, If I were to describe the sound of it, it would be warm, clean, detailed and spacious. Not bad for less than $100.

If you are not satisfied with the sound quality of your android (version 5 or higher) or iOS device, I have no reservation recommending the Calyx PaT. It's a cheap option that has nothing cheap about the sound it produces.
  • Like
Reactions: tarhana
Pros: True Portability, Plug and Play, No Battery, Solid Build, Good Sound
Cons: Lack of Apple Cable (PaT), Slight Hiss with Sensitive IEMs
I currently have the Calyx PaT, Cozoy Aegis, and Cozoy Astrapi in hand. I got these three from my good friend, nmatheis, who sent the three as a set to a couple Head-Fiers to audition as sort of a “phone powered DAC/Amp” tour if you will. For this review, I will be talking briefly about all three of the products. The reason I’ve put this as a Calyx PaT review is simply because I found the PaT to be the most worthy of the three products, and thus I’ve chosen to focus on the PaT as the center of this review.
Packaging and Accessories:
            So in terms of packaging, the ranking goes: Aegis = Astrapi >> PaT. The PaT’s packaging is actually way more basic and unimpressive in comparison to the Cozoy products. The Cozoy products come in a nice white box with the products sitting nicely in a velour feeling material. On the other hand, the PaT comes in a clear plastic encasing that makes me feel like I just bought a cheap remote control from Home Depot or something. A bit exaggerated but not by much – the presentation of the Cozoy products are quite a few steps up from the PaT.
In terms of accessories, they’re quite similar. They all come with various cables for use with different devices. However, the Cozoy products also include a cable with lightning connection while the Calyx PaT does not have such a cable. Fortunately for me I’m using all three products with my HTC One M8, so that doesn’t affect me but it would be something nice to have though.
Packaging - You Can See How Much Nicer Cozoy Packaging Is
Build Quality and Design:
            The ranking for build goes something like: Aegis > Astrapi > PaT. The Aegis, with its brushed aluminum finish, takes the cake as being the finest looking piece of the three. The Astrapi has a brushed aluminum front like its older brother, but has a more generic metal finish for the rest of the piece. Finally, the PaT is constructed of metal with a blue tint to it (you can select from a few choices of colors), with a rubber back. While the PaT doesn’t quite look or feel as premium as the Cozoy products, its build quality is still very good nonetheless – it just takes a simpler approach.
            Ranking the design of the three is a bit more of a tricky matter. They’re all well-designed because the concept of this type of super portable device in itself is a good design. So for me to say one is better in design over the other doesn’t really make too much sense to me. I can say in terms of look, I would go: Aegis > Astrapi > PaT, but in terms of function, it’s a bit of a different story. The PaT is the largest of the three, being almost twice as large as the Astrapi, in fact, so in theory, it’s the least ergonomic. But does size really matter at this point? I say no – these things are already so small that it really makes no difference to me. They all fit in my pocket with no problem, and when I do put them in my pocket it just feels like I have my phone in the pocket. These guys really don’t add much more. All three also drain the battery of the phone, but I found it to be reasonable and I wasn’t running out of battery in the middle of the day because I was using one of these devices.
I actually like the PaT the most of the three when it comes to design. Yes, it’s a little bigger, but it doesn’t matter. What I really like about it is its rubber back side. While perhaps it makes the PaT look a little cheaper, as someone who likes to really take care of his gear and can’t stand a single scratch on anything, I really appreciate the rubber back as it prevents both my phone and my PaT from leaving a mark on one another. I liked the PaT more than the Aegis mostly because the Aegis gets pretty warm real quick when in use. On the flip side, my least favorite is actually the smallest one of the bunch – the Astrapi. I don’t get the clip that’s on the back of the Astrapi. I think it’s small enough as is that I can fit it into my pocket with my phone with absolutely no problem. I don’t think I’ll ever use the clip to clip the Astrapi to my belt or the side of my pocket or anything, so it just becomes a thing that takes up space and a possible place for the Astrapi to break. Admittedly, the clip is well built and feels sturdy, but if anything’s going to get twisted weird and break, it’s the hinges on the back that might break.
One more thing to add is that the PaT has controls. I never got it to work with my HTC phone, but perhaps it works with iPhones. Either way, if the button controls on the PaT do work, it would also be a big bonus to have in terms of its design. Unfortunately I can’t speak for how well the controls work since they never worked for me.
Again, at the end of the day, all three products are built well with good designs. They’re all sturdy and fit in my pocket and disappear. So again, when I say X is better thay Y because of reason Z, it’s really just the tiniest of observations.
Left - Calyx PaT, Middle - Cozoy Astrapi, Right - Cozoy Aegis 
Listening Impressions:
            So this is where the three products really separate themselves from one another. To keep things consistent, all three products were connected to my HTC One M8 running PowerAmp with the Noble Savant as the IEM of choice. Music ranges in a wide variety of genres as well as quality. Another quick note before we start – the Aegis currently runs for around 300 dollars, Astrapi for 130 dollars, and the PaT for 100 dollars.
Astrapi and PaT Comparison
So the Astrapi was a bit of an annoyance for me. For some reason, it seems to have some connection issues with my phone where if I disconnect the Astrapi, I would need to restart my phone to get the Astrapi working again. I didn’t have this issue with the other two devices. The phone recognizes the device, because an indicator on the phone shows up saying that the phone is in “host mode,” but music still comes out of the phone’s speakers. This problem was very frustrating to me and made A/Bing a bit of a pain.
Both devices also have a bit of hiss. It’s not overly present on either device as it’s mostly present only when music isn’t playing. However, I did find that the Astrapi seems to have some sort of high pitched hum along with the hiss, which I found a little distracting. In terms of power, the PaT is also a tiny bit more powerful.
Looking at the two’s lower end, I wouldn’t say either of the two are particularly well extended down bottom, but the PaT does do just a tad bit of a better job. The PaT also has a tiny bit more of a mid-bass bump to it, making its thump also just a tad more impactful – it’s not a big difference though.
The PaT has a smoother and slightly richer/warmer midrange compared to that of the Astrapi. The Astrapi has a little bit more upper midrange energy and treble air, which makes the Astrapi sound crispier and more open, but also a little edgy and unnatural at times to me in comparison to the more organic sound of the PaT.
The Soundstage of the Astrapi feels more open and has more height to it, but the PaT edges it out a bit in terms of width and height to my ears. In terms of imaging within the space, I think both do a pretty good job. Both devices overall sound clean and well controlled.
Comparing the two, I personally prefer the PaT to the Astrapi because the PaT just sounds a bit smoother and more natural to my ears. Performance wise, the two are fairly close, but both are certainly a good step up from what your typical smartphone would be capable of.
PaT and Aegis Comparison
            The Aegis is very much an improvement over both the Astrapi and the PaT, which doesn’t come as a surprise. Impressively, the Aegis is the most powerful of the three, but also the quietest, which I was very happy to see.
            The bass doesn’t have as much of a mid-bass bump to it as the PaT does, but the extension is a very welcomed improvement on the Aegis. It’s certainly not at the level of something like my Sony NW-ZX2, but I’m happy with what it’s capable of nonetheless.
            The midrange, in terms of balance, to me is somewhere in between the PaT and the Astrapi. It doesn’t quite have the warmth the PaT has but it also doesn’t have the edgy tendency of the Astrapi. To me, it’s certainly the most well-balanced of the three, and its treble extension remains very good and open. The soundstage is also more three dimensional in all directions, although I don’t see it as a huge improvement over the other two. Detail and imaging capabilities are also a bit better when listening through the Aegis.
Three Devices with HTC One M8 and Noble Audio Savant
Ending Thoughts:
            So I guess I kind of gave a spoiler earlier when I said that my overall favorite of the three was the PaT. At 100 dollars, I think it’s a great upgrade to your phone that delivers a well-detailed yet enjoyable and smooth sound. I would personally recommend it over the Astrapi at 30 dollars more. I found the Astrapi’s sound good, but a little unnatural and not nearly as enjoyable as the PaT, especially when it comes to portable and on-the-go use.
The strongest sonically of the three devices was, without a doubt, the Aegis. However, I can’t help feel that at around three times the price of the PaT, the price is a pushing it a bit. I can’t really see the benefits you get over the PaT with the Aegis to be worth the 200 dollar premium. For me personally, I would have guessed the Aegis to be around the 200-250 dollars range.
At the end of the day, these Ultra-portable devices are awesome. They do drain your phone battery a little bit more, but it’s by no means at an unreasonable rate. While my 230 dollar iBasso D14 is certainly better sounding than all three of the devices, the insanely small form factor of these devices really puts them in a different realm of portability than your average portable device.
For those that like to use their phone to listen to music for whatever reason it may be (UI, portability, ease of use etc.), I highly recommend picking one of these up. For many consumers, audiophile products are pretty unreasonable in terms of price and design. Why would your average consumer pay 300 bucks to pay for giant block that connects to their phone just to listen to music a little better on the train? Well, I really think there’s no excuse to not pick one of these up, especially the PaT at just 100 dollars. It’s 100 dollars that really goes a long way to improving your listening experience without feeling the burden of carrying a portable device around. Great stuff!
Good review, thumbs up.
Pros: Small, lightweight, plug n play, battery-free DAC/Amp that provides noticeable audio improvement.
Cons: Not MFi-certified, needs CCK. No clip.
Photo courtesy of Onsong Audio
I recently tested out two battery-powered DAC/Amp solutions for getting better audio out of my iPhone, the Cayin C5DAC and Shanling H3. When I ran across @Hisoundfi's great review of the Calyx PaT, I was intrigued. Here was a category I hadn't paid much attention to - a battery-free smartphone DAC/Amp that could also double as a DAC/Amp for your computer in a pinch. When I saw that it had transport controls for play/pause, skipping/skimming through tracks, and controlling volume, I knew I needed to test this out. I reached out to Calyx and asked if they could send me a PaT to test, and luckily for me they were happy to oblige. I'll be sending the PaT off to a some other reviewers soon, so be on the lookout for a some excellent reviews soon!
I received the Calyx PaT from Chris at Onsong Audio, the US distributor for Calyx products to review and then pass on to other reviewers. I am in no way affiliated with Calyx or Onsong Audio, and this is my honest opinion of the PaT. I would like to thank Chris at Onsong Audio for giving Head-Fi members the chance to test drive the PaT, and I hope my thoughts prove useful for fellow Head-Fi members as well as for Calyx.
I'm a 43 year old music lover who listens to a wide variety of genres and artists (but mostly electronic, metal, and modern composition these days). As with a lot of people my age, I've got some hearing issues - some upper frequency loss and mild tinnitus. 
My portable music journey started with the venerable Sony Cassette Walkman and then progressed to portable CD players, minidisc recorders, and finally on to DAPs like the Rio Karma, iRiver IHP-120, iPod, iPhone, and the newer crop of DAPs from Fiio and iBasso. 
My headphone journey started with Sony MDR e888 and Eggos back in my minidisc days. I moved on to full-size Beyerdynamic and Ultrasone cans and Shure E2 and E3 IEM. Those all served me well for quite some time. Then I rediscovered Head-Fi, and my poor wallet...
  1. DAC: Up to 16-bit/48 KHz
  1. Rated Impedance: 32Ω
  2. THD+N Ratio: 0.009% @ 1kHz
  3. Output Impedance: 1.8Ω
  4. SNR: -98dB @ 1kHz
  5. Channel Separation: -70dB @ 1kHz
  6. Frequency Response: 20Hz ~ 20kHz
  7. Dynamic Range: 98dB @ 1kHz
  8. Volume Control: 0 ~ -64dB
  9. Audio Output: 0.8V, 3.5mm jack
  10. Connectivity: PC, Mac, Smartphones, Tablets
  11. Colors: Cyan, Gold, Wine
  12. Dimensions: 60mm tall x 32mm wide x 6.8mm thick / 2.36" tall x 1.25" wide x 0.27" thick
  13. Weight: 20g / 0.71oz
  14. Included Cables: Micro USB OTG, micro USB to USB
The Calyx PaT comes in very simple blister packaging.
Inside you get a simple instruction sheet.
You also get a simple accessories package.
So in all, you get The PaT, micro USB OTG and Micro USB to USB cables, and an instruction sheet. That's it, folks. But really, what more do you need? My usual gripe about the DAC/Amp manufacturer not applying a case isn't warranted here, since you're meant to actively handle the PaT during use to control your listening experience.
Here are the front and back of the Cyan PaT in all its glory. Button functionality is clearly explained in the picture above, so I'm not going to rehash that. The matte rubber bottom provides a good non-slip, non-scratching surface to butt-up against your iPhone or for resting on your computer desk.
Bottom edge of PaT has 3.5mm headphone jack. Top edge has micro USB input.
Here's the size in comparison with my iPhone 5s.
Here's the whole setup.  Bummer it's not MFi-certified, necessitating the use of the dreaded CCK (Camera Connection Kit).  
What could be better? In my opinion, the PaT is just begging for a nice, solid metal clip on the back like the Cozoy Astrapi has. PaT isn't meant to be strapped to your iPhone in a stack. It's meant to be left out of your pocket or bag, so you can use the buttons to control your listening experience while your iPhone is safely hidden away. Having a solid clip would allow you to clip it on your jeans pocket or bag strap (or wherever you wanted) like an old-school minidisc or iRiver remote, for that's what the PaT really is - a remote that makes your iPhone sound better.
NOTE: The buttons are not functional on Android devices. They're only for iDevice users. Sorry, Android users... 
FINAL NOTE: While I purchased the official Apple CCK, @Hisoundfi found a much cheaper version on eBay.  Here's a LINK. The one caveat I'll provide is that unofficial CCK substitutes aren't guaranteed to work across iOS updates, so YMMV.
I'm not going to go crazy with volume-matched comparisons in this review. The simple fact is that the PaT provides a clear and noticeable improvement over the iPhone's already good (but not great) stock sound. It's really as simple as that. There's a bit of extra oomph added in the lower region. The upper end gets some sparkle and shimmer. The music sounds less constricted, the soundstage more spacious. I haven't heard it, but I imagine it's a similar difference as going from the iPhone to something like the Fiio X1. It's your entry into the world of DAP sound without making the move away from your iPhone. 
Volume is controlled by using your iPhone's volume buttons or onscreen volume slider. When using the volume buttons, you get a very reasonable bump up or down in volume with each click. With the onscreen volume slider, you get a very smooth transition from silent to very loud (with the IEM I tested). Contrast this with the Cozoy products I've also been testing. With those, you get discrete volume steps with both the volume buttons and onscreen slider. For example, when you slide your finger across the onscreen slider with the Cozy Aegis, the volume stays the same for awhile as you drag your finger along and then suddenly jumps several dB. I prefer the approach Calyx took.
So what're the limitations? Well, driving power, for one. In his review, @Hisoundfi remarked that it drove 300Ω headphones with ease with his LG Android smartphone. Surprisingly, in @yen262's review, he reported that the Samsung Android phone he used for testing required an amp to properly drive the full-size cans he tested and recommended the PaT only for more sensitive IEM.
With my iPhone, I got pretty much the same driving power as the iPhone itself. When trying to power my HiFiMan HE-400 (32Ω, 92.5dB). Not only did it sound woefully underpowered, I could only reach moderate listening levels. At this time, @yen262's review wasn't published. I was confused and contacted Chris at Onsong to inquire about this. He said that this was also his experience - iPhone is quieter with PaT than Android. It seems the answer is more complicated than this, and either each reviewer's personal feeling on driving power are coming into play or there are phone to phone differences with PaT. I'm not sure why this difference exists. Perhaps someone more technical will provide an answer in the comments.
AMENDMENT: I gave the PaT comparative listen vs. Cozy Aegis and wanted to add an update regarding driving power. While I still think HE-400 could be driven better, I do think the PaT is satisfactory for a small, inexpensive portable solution. I also got a chance to listen with 300Ω VE Zen, and it sounds very nice. So I'd like to retract any concerns about driving power. PaT should do a good job for you with all but the most demanding HP / IEM.
I'm not going to focus on this in this review, as mentioned in the introduction my intent was to evaluate the PaT with my iPhone as a DAP alternative. What I will say is that the PaT worked seamlessly with my MacBook Pro. Pure plug n play goodness that again made a clear and noticeable improvement in my listening experience.
The Calyx PaT is an interesting little audio gadget. While compatible with Android, iPhone (iOS) and full-fledged computer platforms, it seems a best fit for the iPhone. I found it really performed well for my use case, which was providing an improved listening experience with my iPhone on the go with IEM (HP that are easy to drive should be just fine, as well). That's what I was looking for, and the PaT provided it - simple as that. Is it going replace my iBasso DX90 or Fiio X5? No, but at $99 would I really expect that? Again, no. What it will do in my experience though, is make a clear and noticeable improvement to your iPhone listening experience - and that's a good thing.
Could it be improved? Well, yes. For starters, it would be great if the transport controls worked for Android phones. Bummer, Android users. As mentioned above, it's just begging for a clip. I was going to mention driving power here, but since there's no gain switch and only 16 volume steps when using the iPhone I think I like it just the way it is. If there was a gain switch, then I'd expect more driving power. As it is, I think it's perfect for IEM and HP that are relatively easy to drive, and I'm not going to head out the door with my HE-400 on anyway.
Just in case you were wondering, the scores I'm providing are based on performance vs. price point. I haven't specified this before, but I think it's important to mention. 
Again, I'd like to thank Chris at Onsong for providing a PaT for testing. And remember , I'll be sharing the PaT with a few fellow Head-Fi'ers - so please be on the lookout for additional reviews in the near future.
  • Like
Reactions: yen262
It wasn't clear to me from the review, but you can also control iPhone music volume with the volume buttons on the PaT. Interestingly, the PaT and iPhone Music app controls are married to each other when you hook up the two devices, so as you raise or lower the volume using PaT as a remote, the volume slider moves on your phone.
Pros: Best for budget below $100. Good quality build, sleek body and simple design.
Cons: Controls only workable on PC and Apple devices, not working on Androids. Cable for Apple devices is not included, USB camera kit is needed.
Portable music is more mainstream than ever nowadays. Music streaming industry is blooming fast too. Smartphones are so advance and this is one of the main factor which drive the portable music trend. However the sound quality from smartphones is not satisfying because lack of details and synergy.

Calyx is product series by Korean company known as D&A, Digital and Analog Co. Ltd. Previously they were into OEM business until lately they introduced their high-end native DSD portable player Calyx M.
What is Calyx PAT?
Calyx PAT is portable DAC that can be used on smartphones, tablets and computers which bypass the internal DAC of your devices and act as an upgrade DAC enhancing music playback. PAT has minimal design with elegant build and brilliant size. The CNC cut aluminium body is super light and rigid. It has only one digital input (micro USB) and one analog output (3.5mm stereo). Calyx PAT does not have internal battery. It needs very minimal power to operate and it does not drain much power from your devices so no worries on this. Calyx PAT is very easy to use, just plug and play, no driver needed.
Calyx PAT available in 3 colors: Gold, Blue and Red. It comes in simple and small packaging. Inside the packaging there are Calyx PAT and 2  cables: Micro USB OTG and USB to Micro USB.
The Imperfections.
I personally think that Calyx PAT is a very perfect portable DAC without these 2 imperfections I am going to mention. These imperfections are very small, no big deal, I am just being picky here. Firstly the control is not working on Android devices. Anyway the control is just a plus feature, Calyx PAT still working great without control. Honestly we use device's on-screen control most of the time. The control is working on iOS and Windows OS.

The other imperfection is that Calyx Pat does not come with stock cable for Apple devices. You will need to buy the Apple Camera USB Kit in order to use the Calyx PAT with Apple devices. Besides, connecting another adapter cable will only increase the cable length and this will reduce the portability.

Inside the Calyx PAT.
I opened up one of the Calyx PAT and took some photos. Here you can see that Calyx PAT offers top notch build quality. Its circuit is quite direct and simple. It's sound is clean and without coloration.
The Sound.
Calyx PAT is entry level DAC which is designed for maximum portability and operate with minimum power. It only able to play up to 16bit 48 kHz. Please do not expect it to play DSD. Calyx PAT is the upgrade for device's in-built DAC. I tried the Calyx PAT on several in-ears and headphones with Samsung Galaxy S4, Samsung Galaxy Note 2 and iPhone 5s playing 16 bit 44.1 kHz FLAC and Apple Lossless. It benefits the in-ears more than headphones because the output power is not high and it drives the low impedance yet high sensitivity in-ears very well. The signature is slightly warmer. It gives you the presentation with more details, slightly improved synergy and slightly better sound stage. Besides, it enhances the low frequency and give more bass. Calyx PAT does bring out the details compare to in-built DAC. The improvements and enhancements are there but not very impressive that will blow you away.
For headphones, it is capable to drive low impedance portable headphones (32 Ohm). However it is recommended to pair it with an amplifier to get more synergy.
Power Source : USB
DAC : 16 Bit / 48 kHz
Output : 3.5 mm Stereomini, 0.8 V, 1.8 Ω
Dimension : 60 mm (H), 30 mm (W), 7.5 mm (D)
Weight : 20 g
Color : Gold, Blue, Red
Accessories : Micro USB OTG, Micro USB to USB

The Conclusion
Well, Calyx PAT definitely is a good buy for $99 (RM399) for entry level DAC if you ask me. It offers good build quality, good portability and good sound. If you are looking for entry-level DAC upgrade and you are using in-ears then I would recommend Calyx PAT to you. If you are using headphones then I would recommend you to pair another amplifier with Calyx PAT to drive your headphones to its potential. Calyx PAT is low cost, excellent sounding for the price, compatible with PC and mobile devices, such worthy product not only recommended to audiophile but everyone who appreciates good sound. Highly recommended.
Pros: Easy plug and play function, No charging required, Extremely convenient and pretty versatile, Controls for Apple and PC
Cons: Controls don't work for Chromebooks and Android, An aftermarket USB camera adapter is needed to use it with Apple products
When I attended the Axpona Audiocon in April, I walked away with a huge smile on my face. This was the first time being able to listen to the world's best headphones and DAC/Amplifiers all in one place. It was a "kid in the candy store" type of moment going from station to station, popping on the likes of the HD800, HE-1000, Oppo HA-1, Astell & Kern AK240 and on and on... The list of goodies is literally too long to put up, but with the few I named you should get the idea. It was awesomesauce!
Walking away from the event left me with a few lasting impressions. One was meeting Zach from ZMF and seeing how cool of a person he is, and seeing his passion for making high quality custom modded headphones. Another was listening to the Noble Audio Kaiser 10-U and realizing it sounds even better than I thought it would. The third was checking out the Calyx booth to see the M player, and getting a first listen to the not yet released PaT. Today we will discuss the Calyx PaT.
Chris from Onsong Audio was behind the Calyx booth. I was very impressed with his Calyx M DAP. The sound was phenomenal and it sported a lot of very cool features. It was very responsive and had a very nice user interface. I had to admit to him that in order for me to fork over a stack of cash for a DAP like this, I would have to have streaming capabilities. My response to Chris was "give it streaming capabilities and I'll pay an extra $500 for it." It was at that point as I was about to get out of my seat and move to the next booth that Chris suggested I try the PaT, a portable DAC/AMP that didn't look like much at first glance. I plugged it into my LG-G3, fired up some Google Music, hit the play button and was pleasantly surprised with the sound quality this thing was pumping out. Thirty seconds of listening to this thing and I asked how much it goes for (thinking this is probably going to be a pricey little gadget). When he told me the MSRP was a measly $99, I offered to buy it on the spot. Unfortunately that wasn't an option as this was a demo unit. I took his card and followed up with him after the event. As soon as Chirs had the PaT in stock I bought it. It was a must have.
The PaT is a simple little gadget that comes in very simple packaging that serves as nothing more than a means to hold the product and protect it from being damaged. It comes shipped with a couple cables (USB to Micro USB, and a Micro to Micro USB OTG cable) The device itself is made from a milled aluminum and has a rubber backing on it which is very clever and allows it to be strapped to the back of any phone or device without scratching it. There is some very stylish laser etchings on the front, along with a five button remote. The top of the unit has a female Micro USB input. The bottom of the device has a 3.5 mm headphone jack for an output. I find the design to be simple, stylish and ergonomic. The PaT comes in three different colors; gold, cyan (blue) and wine (red). All of them have a metallic finish and appears to be very resilliant and doesn't look like it will fade or get scratched if handled with a respectable amount of care.
The PaT is a no frills concept. There's no battery to charge, there's no settings menu and no drivers to download and install. Simply plug this little guy into anything that has a digital output and you're ready to rock (for Android devices version 4.0 or more with OTG support is required).

Power Source


Rated Impedance

32 [Ω]

THD+N Ratio

0.009 [%] @ 1kHz

Output Impedance

1.8 [Ω]


-98 [dB] @ 1kHz

Channel Separation

-70 [dB] @ 1kHz

Frequency Response

20 [Hz] ~ 20 [kHz]

Dynamic Range

98 [dB] @ 1kHz

Volume Control

0 ~ -64 [dB]


Gold / Wine / Cyan


60 X 30 X 7.5 [mm]


20 [g]

There is a couple things about the device that struck a small nerve with me. First and foremost, the controls don't work for Android and Chrome OS, so this is pretty much a plug and play device for these sources. On a more positive note regarding this, the PaT is so small it really isn't a big deal. If it's bound to your phone or plugged into your chromebook it's just as easily controlled with the source you're using.
The other pet peeve I had with this thing and the main reason I was delayed in my review is that in order to use it with Apple products a USB camera adapter is required and not supplied (not cool in my opinion). On a more positive note, I was able to find a very cheap USB camera adapter on eBay for only $4 USD, and it worked flawlessly connecting it to my wife's Iphone 6 Plus and Ipad. Here is a link if you are interested:
I tested and confirmed that all of the buttons functioned flawlessly and without any lag with my Apple testing devices. If there was any delay it was from the Ipad or Iphone loading the music. The buttons also worked flawlessly with my Windows laptop.
Now for the good part. I find the output power to be in a sweet spot so that it works great for just about every IEM and headphone I have. It can drive highly sensitive IEMs, and high impedance full size headphones without any adjustments. With highly sensitive IEMs I do get a very faint hiss, but once the music is playing it isn't audible whatsoever. The real beauty of this thing is that I can drive my 300 Ohm Sennheiser HD600 with ease with the PaT from something like a cell phone and it sounds great! This is a part of why I enjoy the PaT so much, it's ergonomic, easy to use, and you won't catch yourself farting around with gain settings, bass boosts and so on. It doesn't have these options and it honestly doesn't need it. The tuning is good enough that those things aren't necessary in my opinion.
The louder you turn the volume up the quicker the battery drains on your device (remember, the Calyx PaT draws its power from the source) but I don't find it to be significant. I always carry an extra charged battery for my LG-G3 so I never run into a case of my battery draining before the day is over. The extra battery and Calyx PaT gives me a really dependable portable rig that doesn't need a wall charger or cables to get through a day of heavy usage. 
The best way I could describe the sound of the PaT is engaging with a rich and detailed presentation that will definitely improve the sound over your cell phone or computer's headphone jack. There is a very slight warm tilt that doesn't put too much weight on any vocals. Male and female voices sound very natural and organic. I can sense a sub layer that adds a nice amount of depth and dimension to music. The top end of the spectrum has a nice sparkle that is natural and not overdone. I would consider it to be crisp but not bright. There is a good sense of separation that puts a nice amount of air between each instrument. It's good in this sense but it's not going to blow you away. It can't hang with DSD (Mass output is 16/48k) but don't let that discourage you or make you think this thing isn't capable of pumping out some audiophile caliber sound. I don't know if there's any DAC/AMP currently that puts out a combination of ergonomics, ease of use, and sound quality for a price this low.
This thing isn't going to completely destroy your AK240 so don't sell it for fifteen of these LOL. The PaT is good at what it sets out to do, which is take your phone, laptop, Ipad, or Chromebook and make it sound more audiophile and all for around ninety-nine bucks. It will make your music files, Itunes, Google Music, Spotify and Tidal sound that much better to the point that it justifies its asking price and then some. To be honest it satisfies my portable audio needs, and probably saved me from spending a wad of cash on another DAP I don't necessarily need. I'm VERY content with this and my LG G3 as my portable rig at the moment. It all fits in one pocket and lasts all day, and don't forget it has the ability to drive just about everything you throw at it upwards of 300 Ohms. Pretty impressive if you ask me!
If there was any adjustments or tweaks that could/should be done, I would like to see the controls to work for all platforms. I would also like it to come with all the cables needed to hook it up to all of today's devices (I'm talking about the USB camera adapter for Iphone/Ipad). If they could make these improvements, and up the sampling rate to 24/96k, I would pay an extra hundred or more for it.
If you are an Iphone user and want a perfect DAC/AMP companion to piggy back it and take your portable tunes to the next level I STRONGLY suggest this. If you can live without the controls, I promise this will upgrade the sound quality of your android phone. If you have a Mac or PC and want a DAC/AMP that will awesomify your music, and you're looking for that with an inline remote to boot, your answer is here with this very cool little gadget.
The Calyx PaT takes phone audio to the next level, and can make any device that has OTG support sound phenomenal. If you're in the market for something like this make sure to check it out. I can almost guarantee you won't be disappointed in its ease of use and performance.
Here is Onsong Audio's site where you can find links to purchase the Calyx PaT:
Thanks for reading and happy listening!
No worries, FiiO told me how to buy the E18 micro USB OTG cable separately for $7 incl. shipping from Aliexpress :)
Anybody tried to use it with a lighting/microUSB adapter or cable? Trying to find a solution to avoid use it with two connection cables attached.