The decision to axe the iPhone’s built-in headphone port and simply put an adapter in the box has provoked reactions ranging from amusement to near panic. Why did they do it? Was it worth it? Will other manufacturers copy it? Today we’re going to ignore all of these questions. Instead we’re asking, How did they do it? And since we like taking things apart, we’ll answer with some exploratory surgery and some X-rays.
Apple feels the 3.5 mm audio jack is an antique whose time has passed. But we’re not all prepared to shell out for new headphones just yet, so to ease the transition Apple gave iPhone 7 owners a deal worthy of Oprah—you get a headphone adapter! And you get a headphone adapter! Everyone gets a headphone adapter!
Separately, this little adapter retails for $9.00—making it pretty much the cheapest thing in the Apple store, where you can drop $35 for a simple screen protector. So, you’d probably think a $9 dongle doesn’t have much going on.
Imagine our surprise, then, when our pals over at Creative Electron gave Apple’s new adapter the X-ray treatment:
Thanks to Creative Electron for this X-ray image of Apple’s audio adapter.
There’s actually a lot going on in there. As expected, one end is a simple female 3.5 mm headphone jack, and the other end is a male Lightning connector. But what’s all that silicon around the Lightning connector end? Most of the retail space near the connector is taken up by a single mystery IC.
Image courtesy of the amazing folks at Creative Electron.
We needed a closer look. Thankfully, long-time iFixit contributor and gadgeteer extraordinaire oldturkey03 sliced his adapter open so we could all get a peek inside. He uncovered that mystery IC by the Lightning connector, marked 338S00140 A0SM1624 TW—which doesn’t tell us much, other than it’s an Apple part number.
Thanks to longtime iFixit community member OldTurkey03 for his teardown of the audio adapter.
While the official purpose of this IC is unknown, at minimum we can guess that it contains a digital-to-analog converter (DAC) and amplifier, and its counterpart, an analog-to-digital-converter (ADC).
We know this because audio accessories like earphones (as well as human ears) need analog signals to work—and unlike ye olde analog headphone jack, Apple’s Lightning connector is all digital. The DAC bridges that gap. By the same logic, this chip must also contain an ADC circuit to convert the analog signal from your headphones’ built-in mic into something that can pass back through the Lightning port so your iPhone can make use of it.
In past iPhones like the 6s, both DAC and ADC functions were handled internally. The analog inputs and outputs from the headphone jack (and other components) were wrangled by a single chip on the logic board, a custom Apple/Cirrus Logic IC labeled 338S00105. (In the iPhone 7 and 7 Plus, that same exact chip still exists—because even without a headphone jack, the phone still has to shake hands with other built-in analog components.)
Apple/Cirrus Logic 338S00105 audio codec in the iPhone 6s (left) and iPhone 7 (right).
The moment Apple’s plans for a headphone adapter first came to light, audiophiles began questioning whether such a tiny dongle—and, presumably, the DAC + amp buried inside—could possibly supply a quality audio experience. Speculation was that, in order to fit aboard the adapter, the audio hardware would have to be so small that corners would inevitably be cut.
Well, here’s a visual comparison of the audio chip on the iPhone 7’s logic board, photographed right next to the exposed chip on the new adapter:
This isn’t an oranges-to-oranges comparison however, because each of these chips handles more than just DAC/ADC. The larger chip is also a codec, and is not believed to contain an amplifier (there are three amps located elsewhere on the iPhone 7 logic board).
In short, a more scientific approach is called for. So upon its release, hi-fi enthusiasts at German computer tech magazine c’t ran a battery of sound quality tests on Apple’s new adapter. After taking baseline measurements from the old-school, built-in headphone jacks on an iPhone 6s and iPad Air, they compared the adapter’s output on iPhone 6s, iPad Air, and iPhone 7:
Hi-fi enthusiasts at German computer tech magazine c’t ran a battery of sound quality tests on Apple’s new adaptor and broke down the results.
The takeaway seems to be that in some areas, the sound quality does measure a bit worse from the adapter than we might be accustomed to. For instance, when playing an uncompressed 16-bit audio file on the iPhone 6s, the dynamic range dropped from 99.1 dB at the headphone jack to 97.3 dB at the adapter. Though keep in mind, this slightly lower measurement is still higher than the theoretical maximum you get from a compact disc (which is 96 dB). So, is it a difference you are likely to notice? If you sit in a quiet room with a really, really good pair of headphones … and you’re a canine, the answer is: maybe.
But it appears Apple’s engineers did their job, and this tiny adapter performs better than most people expected or even thought possible.
Why did they do it? Was it worth it? Will other manufacturers copy it? Give us your thoughts.
They needed a DAC to drive the new enhanced TapticEngine. Easier to steal the one that used to power the headphone jack and make the headphone DAC external than reengineer all those DAC subsystems. As a bonus they would be able to make it waterproof with less engineering. Should be able to be proved if someone can trace the TapticEngine to one of the three DAC’s still on the motherboard.
Notes: The German measurements are only valid for iPhones shipped in Europe, due to EU regulations about maximum volume enforced for devices that ship with headphones – the connector used with a U.S. iPhone will exhibit higher output voltages (and as a consequence a relative higher DNR and lower noise floor)
As for the chip itself, and which manufacturer does it for Apple? My pet theory (which may be entirely wrong) is that it’s a variant of one of the brand new Audio Codecs launched by Dialog Semiconductor. Some of them also seem to match the form factor of this one.
It is no sense having a dac in the external chip if it hasn’t an amplifier after the dac. And there is no place for an amplifier in it. Or is it? I don’t think so, it would be a really incredible miniaturization work!
It is not very hard to integrate an amplifier inside a DAC chip. The hard part is making a DAC with nice linear output.
What I would like to see is if a USB to lightning adapter would let a $9.00 Apple DAC work like many of the USB DACs that people are using for high quality PC audio.
Looking on eBay some of the imported adapters are less than $2.00 so that would make possibly the cheapest USB DAC available and knowing Apple, the audio quality would probably be better than decent, especially if you could power it from a clean supply.
There was speculation that the iPhone simply passed through an analog on the Lightning port. Has this been discounted since it would need to always be a pure digital signal on the wires?
Looking forward to buying a pair of air pods in a couple of weeks!
I REALLLY don’t understand what the “mystery” is about. Regardless what anyone says, all Apple has done is to move the D/A converter from inside the phone to outside. Does it sound better? It MAY sound better, but it has absolutely nothing to do with whether the converter is inside or outside of the phone. What makes it SOUND better is a BETTER D/A converter.
My guess is you’ll find exactly the same chip in the new TB headphones as well.
Really… its not a mystery
There’s digital audio & there’s digital audio.
The adaptor could receive partially-decoded audio from the phone, which would be easily converted to analog. A “Class D” (Pulse-Width Modulated) signal, for example, which only needs trivial amplification with very low linearity requirements. I would expect to see some sort of a capacitor to reduce the high-frequency noise this normally produces, but perhaps a teensy bit of cleverness in the “DAC” chip could do it digitally.
All speculation, mind you, but consistent with such a tiny amount of circuitry.
We need measurements of jitter, because to a very large extent that defines the audio quality. You can buy the cheapest CD player with digital-out, then feed it into an expensive outboard DAC and it will sound brilliant, largely due to the low jitter in the outboard DAC.
Please note: the 1624 part of the number is a date code: 2016, 24th week. That’s when the chip was built
@coolfactor, these adaptors work in older iPhones and older iPhones did not support analog audio on the lightning port.
I got an iPhone 7 Plus a week after launch to replace my 6 Plus. I use Bluetooth headphones most the time, but in my car, which doesn’t have Bluetooth audio, I always plug into the aux port. So when I got the new phone I intended to leave the adapter permanently in the car, but after trying it I found using the adapter caused so much background noise I might as well have been listening to a cassette tape. This was never an issue with my 6 Plus. The idea of consolidating ports is something I can understand and get behind and I like that Apple are brave enough to lead the way for other manufacturers to strip bulk from their products. But the problem here is rather than boldly slashing a path for other manufacturers to follow that will, when everyone’s on the same page again, make the ecosystem better, the fact that the lightning cable is proprietary means they’ve just made headphones as compatible as laptop ac adapters.
That’s actually a good point made. To what degree does interference (background noise) occur now that it’s external and very little if any shielding?
Anyway, I get what Apple is trying to do here, inject some motivation to wireless audio. However I’d have more praises and could get on board if they offered at the same time a better listening experienc. Bluetooth does not sound better and even Apple still doesn’t supported encodings like aptX even with this jack removal. Also the lag Bluetooth adds is horrendous and irritating beyond belief. They didn’t add anything to compel any innovation or adaptation. That would have happened anyway if Bluetooth was a better alternative then the physical line. What they did was basically close the door, added a surcharge (lightning port license fee) and managed to create what is comparible to and essentially adding a micro fee to get music back out of the phone after paying to put it on it. What would have been “brave” woulda been open sourcing the lightning port if it’s so much superior to USB, adopt superior wireless encodings which increase the quality of wireless music opposed to wired interfaces. That would have been “brave”.
Great content. I’ll be picking up an adapter tomorrow and quickly amateur run square wave and RMAA tests on it through a Lynx HILO ADC. 0,37Ω and what appears to be a democratisation of output between devices seems good.
I don’t listen to music averaged above 80dB anyway, so I’m not worried about much besides signal stability, though I also have the sneaking suspicion that Heis.de’s tests are volume-cap limited, if not beset by ADC issues. My measurements of the iPhone 6 (not S) show better dynamic range, but 0,0015% THD rather than 0,001%.
Of course, the tools I have at my disposal are not meant for measuring or calibrating audio outputs.
I’m unsure if you can read this criticism of the adapter, which relies mainly on its jitter performance @ 1kHz.
https://www.facebook.com/larry.ho.heyuan/posts/10157409342390532
I’m mainly agnostic about jitter because I have many acquaintances that swear by DACs that spout loads of jitter, and others that swear against the same DACs. In some instances, measuring bad or good is irrelevant.
Still, very interested to get my adapter tomorrow.
One thing that no one has mentioned is that medical devices (such as for blood-glucose analysis) also use the 3.5mm port. They need full volume (i.e. a good signal) so this may ensure that these would continue to work. I have not tested this yet, but Apple is unlikely to drop an important section of a market (health) it is trying to build.
So what about the included earbuds with lightening connector – does that mean they now have a DAC built into them as well?
I’m not an audiophile, but I am curious to know what else this dongle can be used for–both without and with simple changes made at the pin-out to the digital end.
I am an audiophile and I was immediately disappointed with the sound quality of the adapter on my new iPhone 7 Plus. Comparing side-by-side with my iPhone 6 Plus, the iPhone 7 Plus with dongle sounds noticeably flatter and lacking in dynamics, and I found myself turning up the volume quite a bit more in attempt to recover that lost sense of “snap.” Bass does not hit as hard as I’m used to either, nor does it dig as deep down low. There is also a sense that the high frequencies are somewhat veiled, causing music to lose some of the “air” I was accustomed to on the iPhone 6, making certain types of music sound lacking in transparency. This was via a pair of Sennheiser Momentum 2’s listening to Tidal streaming service (hi-res files). Perhaps with time, more specialty manufacturers will release higher quality adapters – and better DACs – than this one. Of course I could always also go out and buy a dedicated, standalone DAC, but I don’t really want to have to carry two devices with me. So as it stands, as an audiophile, I am massively disappointed. Luckily my ipad pro 12.9″ still has the 3.5mm jack and a better DAC execution (switching between my iphone 7 Plus and the ipad pro is a night and day difference), so I’ll probably carry my ipad with me more when I want better sound quality.
@Ptan1101:
I’m sure you hear what you hear, but the data doesn’t bear out those opinions. Both my measurements, and others show that the adapter is good to great. I’d love if someone could conduct a large-population volume-matched double blind ABX test. It may be that listeners can tell the difference, but I doubt that one would be chosen en masse over another, listeners being ‘audiophiles’ or not.
Headfi’s science forum has an amazing post #292 showing that the major difference is just THD/jitter, but at such a low level that likely it is inaudible.
http://www.head-fi.org/t/627111/what-is-the-sound-quality-of-iphone-ipad-ipod-touch/285#post_12872457
My own measurements:
re: THD and jitter: http://ohm-image.net/opinion/audiophile/thd-jitter-apple-lightning-to-35-mm-headphone-adapter-vs-iphone-6
RMAA: http://ohm-image.net/data/audio/apple-lightning-35-mm-headphone-jack-adapter-24-bit
@ohm don’t try to reason with an audiophile with science, he will just tell you that he can still tell the difference.
Unless it’s double blind of course. Then he won’t be able to tell an iTunes Plus track on an iPod Shuffle, from a FLAC played through a $1000 receiver and a tube amp. Lol.
But if we want the best sound: isn’t it an advantage to have the digital audio stream available from the lightning port? All you need is a set of headphones that have good DA and amplifier built in. Then you can tune the DAC and Amp specifically to the characteristics of the headphones. (Which is one of the best ways to get really great sound. ) And feed it with digital sound from the iphone.
The Samsung s7 audio has a mode where it sends pings at different power levels and frequencies to the two speakers in a headphone . The user is required to press a button whenever they can hear the ping. This way it tunes the audio output to both the earphones and the users ears. It really works in clearing up audio … And it “put manners “on a set of JVC earbuds . I had which were very sibilant. . I am curious, does any other vendor offer an equivalent function.
@Ptan1101:
I’ve tested it with my iPod touch 6th gen (which in my opinion is the best sounding iOS device), and I can hear a sound improvement using the adapter. The soundstage is wider, bass is more controlled, and more airy. I’m using FitEar MH335DW with silver litz cable as my earphones, and I tested this using Apple Music files as well as hi-res 24bit/192kHz files through Onkyo app (although they obviously get downsampled).
So perhaps it also depends on the characteristics of headphones/earphones used to listen as well. But so far I’m very happy with the adapter’s sound quality.
Awesome conversation, A quick question though.
Will cutting the wire in between and attaching a female Lightning along with the 3.5 let me recharge my phone while listen to music. Will the a/d cause an issue or destroy my ear phones. will this setup bring down the sound quality?
Reason: I project a lot of my business presentation from my Iphone. In the earlier days (6s and before), I was able to connect the lightning to VGA to projector and the audio out to 3.5… I don’t have that choice now unless the projector I am using has HDMI Capability.
Across all the devices a 44.1kHz files has an upper cutoff of 21.2 kHz, and a 96kHz file cuts off at 19.1kHz ????
What happened to the Nyquist principle? Are there no benefits to using higher resolution files?
Excellent article, sir! I will now know to say “Sure, that adapter is adequate, you needn’t buy Lightning nor Bluetooth headphones, unless you want a bit better experience”. Definitely worth a $10 try-out for most people, though the connector doesn’t appear to lock-in the headphone plug.
Very upset that Apple removes a port (without replacing it) and obliges everyone to go into the lightning format, while the universal jack does a really good job.
Analog jack is actually always better than the bluethooth.
And you do not need to charge your Earpods.
And there is no battery inside the Earpods, while there is in the Airpods. So you can throw them away when their batteries are too old.
I think ifixit should be totally against this move from Apple.
Today I bought an Iphone 7 and am so disappointed by the sound quality of the adapter! I am not an audiophile, I’m used to the sound of my old iphone 3gs paired with the 3.5″ earpods, which give much better sound in terms of clarity and detail. On the Iphone 7 both with the included lightning earpods, and the old 3.5″ earpods via the adapter, it sounds very cheap, not much better than an audio cassette, really no exaggeration here!
Reading the article and comments here and on other places, people (and measurements) are generally happy with the quality of the new DAC, which is so different than my first impressions, that I come to a conclusion that some items or whole batches are not as expected, or do not perform as expected in more EM-noisy environments (I have no idea if I live in such place). If it was just one of the 2 (the adapter or the lightning earpods), it would have been a bad unit passing through QA, but both?
I have listened to music on so many Apple devices that I never questioned the sound quality of the new iphone I was going to buy, the sound quality was actually one of the main reasons I bought it. At least the problem can be fixed if/when a new proper adapter is released by Apple or some other company.
@stefan
Your observations are backed by nothing but anecdotes. The adapter has been shown to output overall better signal quality than the iPhone 6 with only marginal trade offs. If it sounds like cassette to you, something is wrong with your placebo.
Dear PTan1101: Tidal is not high resolution. It is CD quality only. 16 bit/44.x kHz. “Perfect Sound Forever”
If you want high resolution you have to download true PCM 88-192kHz/24 bit files or DSD (SACD) files from HDTracks.com or other services. That is why Neil Young came out with his Pono (/) device. There is no true streaming (close to real time) high resolution service I am aware of.
No matter what you download to your iOS device, seems it won’t matter anyway because Apple wants to cut off output at 19-21KHz output no matter what the device is you use to output the analog or digital signal.
That being said the output from the analog headphone jack in my iPAD mini 2 (?) is much better than that in my ASUS PC that crapped out on me in one channel after 3 weeks of connection to my home stereo system. In fact, I think the iPAD jack may sound better than the same signal (SiriusXM Chill station) bitstream output from the USB 2.0 port on the laptop to my high quality (32 bit) DAC that goes into my home sound system. In addition, the PC is connected by a CAT 7 wire to its “Gigabit” Ethernet chip input directly into the cable modem whereas the iPAD is using WiFi! Certainly the measurements the German magazine did shows the little jack has a better dynamic range and distortion/noise measurements than many cheap CD or mas market home theatre devices.
The little chip in the Lightning headphone adapter has a bandwidth limiter in it just like the internal “DAC” in earlier iOS machines. I guess they put “codec” into the firmware in the cable.
Why should Apple, Samsung care if they actually have suppliers stating the frequency response of wired earbuds to be 5 Hz-40kHz? +/- 100 db? Just don’t get me started on iTunes!
This is mostly high faluting BS.
I’ll stick with my iPhone 6.
Thank you
@ohm I hope not to disappoint you with my methods and I appreciate your intolerance for snake oil audio. If you can think of anything else I can do or anything differently, please let me know!
I’ve had an iPhone 6S plus for a few years and know it’s audio limitations very well. I will say one thing about Apple and their seemingly lack of interest in audio quality. The hardware has been there for support of HRA (anything RECORDED above CD quality preferably 24/88.2 ) but Apple has been lazy to make any advances in audio quality. I’m going to buy a dongle that will allow me to charge while listening to reference material with the new lightning headphones and the older headphones all OEM parts. I’ll then have my lovely assistant (wife) administer an abxx test (the extra x will be her inclusion because of her lack of interest in all this stuff :). I’ll report back with my opinions, and that’s all they’ll be – opinions. I don’t have the necessary equipment to deliver a truly objective test ie measurements taken in accordance to SAE protocols. I’m also going to try the aforementioned abxx with whatever headphones are available in a friend’s studio.. Afterwards we can all argue about high resolution audio and what we expect!
This review is not reality. I checked out the reviews on the new adapter for the 7. It gets 1 star from everyone.
1. Sounds worse, pops, craks
2. Many people have broken it, the ends pull off
3. Uses more energy since the phone has the old dac + new external dac
4. Its fragile, and easily lost.
5. It was NOT NEEDED it was done for control not to help users.
I won’t buy a IP 7 due to this omission.
Anyone know if you can output multi-channel from a lightning connection? I want to send DTS 4.1 Audio out.
I have the Sennheise HD630 VBs and you definitely hear a difference… so if you want good quality music you should buy a high quality mobile dac/amplifier not only for iphone 7 but also for all those 3,5mm headphone jacks built in any other phone or laptop.
I’ll help with a coherent answer:
I have the iphone 7.
I bought an Oppo HA-2SE DAC
I have the little Apple Dongle (lighting to analog DAC/AMP).
I have some of the best headphones around SHURE SE846 and Sennheiser HD-1.
I also have one of the most epic AV installations on earth for a primary system… but I won’t get into this. Suffice it to say I have spent crazy money on audio stuff.
Since volume matching the HA-2SE and the native dongle is not so easy, its hard to do a “perfect comparison”. It has been shown in numerous studies that even a 1db difference in volume, the louder setup will typically sound better. If you hand me the headphones (blinded and unable to tell what dac is being used, with the same source material), I CANNOT tell the difference between products consistently.
Both the apple dongle and the Oppo can sufficiently amplify both styles of headphone. Neither has significant audible hiss which would typically be a bigger problem on the more sensitive speakers.
So far as audible sound quality differences using Apple Music based content…. the answer is NO. With headphones, most people can’t even get the noise floor of their room/listening environment down low enough to be able to tell.
MAYBE if someone got you a hi-res audio file (above cd quality) then MAYBE with a 130+db S/N ratio amp (like my Benchmark AHB-2) and ultra sensitive speakers, you MIGHT be able to tell differences in sound quality.
Using headphones and without a low noise floor room, with the typical modern dac…. 99.9999% of users are going to not notice substantial differences. Assuming you knew what jitter and sibilance sounded like and could actually pinpoint it (this is seriously debatable for most people btw), it still would not take away the enjoyment of the music for 99.999999% of people.
Having said all this, here is what I want:
Bluetooth that can transmit directly to the headphones WITHOUT additional compression as is currently the case. The receiver on headphones needs to be AAC conversion compatible (which I am assuming that Apple’s Airpods are).
I am convinced with the overall sound quality of apple’s dongle but not the implementation (such as not being able to do 2 lightning headphones off the same dongle or charge the phone at the same time. They do make some third party stuff but I have no idea if they are either good DAC’s or prone to noise and radio interference from the power circuits.
Apple’s DAC dongle is also very flimsy and looks like it won’t last particularly long with heavy use.
Power consumption seemed reasonable with the dongle which is good I suppose. I use a portable battery on plane trips and whatnot to recharge the phone from time to time. In general, iphones suck at battery life if you actually USE them or have the screen backlight on.
FYI: if you spend most of your time on a plane… debating DAC characteristics in that noisy environment is moronic, especially if you are introducing the noise cancelling of Bose headphones into the midrange.
Long Story Short: the Apple DAC/Dongle/Lightning thingamajig will work for the vast majority if it reasonably works for an audio enthusiast (nut) like me. Spend your money on the Headphone type as this will be the most audible part of your experience. The Shure 846 delivers high quality despite being priced premium for what it is and Sennheiser HD-1 headphones are about equally as good in overall experience but cheaper.
The compact convenience of the apple dongle beats the Oppo DAC for sure. Just spend the money on a standalone battery pack (like Anker).
I can definitely notice the difference and even ran blind audition (with the help of my brother) & “won” it.
The sound from adapter on both iPhone 5s & iPhone 6s was likely flattened in the mids and highs. The dynamic range got definitely worse with adapter. I was hearing rather cheap but really sounding headphones as well as monster turbine pro gold & copper (my brother bought the golds, I got the coppers).
And to be fair, I belive I’m a human – not any “canine”. However, the author is likely a victim of the bears were dancing on his ears, so believes only a “canine” should hear any difference in perfect environment.
Could it be that the people who are disappointed by this audio adapter are using headsets that need a lot of power? I am using a large Sennheiser , I don’t remember the model but it is in the $350 range: at max volume it is still not very loud, definitely not as loud as on my Samsung S5. And then yes, it lacks “punch”.
Maybe this adapter is designed only for the small in-ear things?
The gauge of the wires in this dongle is minuscule, it looks miserable compared to the fat wires of the headphones. I also think that it will soon break.
In any case, I don’t get it: I thought Apple was serious about sound quality, and this is the only option besides blutooth (which I heard is not great).
Also, I now need to have three dongles: two headphones and one car audio-in AUX.
The factory needed an introductory product to streamline product manufacturing and to build upon with future upgrades.
It was introduced because the noise floor of the ADC and DAC components can’t be isolated well enough any better at these points within the main’s internal architecture
…most likely.
lol at the amount of people who think sample rates above 44.1kHz and bit depths above 16bit equal “better sound quality” for end-user listening. Music isn’t the same as photos, so increasing the resolution doesn’t get you ‘more detail’, it only introduces supersonic frequencies that will *at best* not improve your audio whatsoever, but are more likely to WORSEN it.
Shannon/Nyquist had it right in the early 80s/late 70s. at 16bit 44.1khz, the wave is LOSSLESSLY recreated. If you care about digital audio, either just trust me as a stranger on a forum, or read this: https://people.xiph.org/~xiphmont/demo/neil-young.html and stop wasting space on ridiculously inflated audio files that are more specifically suitable to dogs. We can’t hear over 22khz guys – most of us have big drop-offs around 16khz for crying out loud. And on the subject of crying out loud, do you really need more than 96dB dynamic range? Let me answer that for you: you don’t. So 16bit is more than enough.
Thank me later and just go and enjoy your music. :D
thank you very much i fix my i phone 7 adio
Count me as another unsatisfied customer of the adapter. I’m very skeptical of the measurements supposedly done by the German magazine that this article touts. The theoretical maximum dynamic range of 16-bit linear PCM is 96 dB (even this article states as such), yet they somehow measured between 97.3-99.9 dB. If they are getting more dynamic range OUT of their tests then the source material could have possibly put IN to the test, this is a major red flag that either the DAC is not decoding linearly (and thus sucks) or, more likely IMO, their measurement methods are flawed. Either way, not a good sign.