Apple Lightning to 3.5mm Adaptor As Your Source

I like simplicity. My audio chain is only as complicated as it needs to be. Right now I’ve got my source, a passive preamp, and an amplifier. About as simple as it comes. Recently I’ve been experimenting with getting my system completely off grid. Just for kicks, I decided to use my iPhone 8 as my source to stream some Tidal and compare it to my CD player’s sound. It doesn’t have a 3.5mm connection, so I had to use a Lightning to 3.5 mm adaptor, along with a hand-made silver 3.5mm to RCA cable which is very transparent. I played some of Brooklyn Duo’s Session V album and was pretty shocked by what I heard. It was not low-end sound like I was expecting. It was very clear sounding, the strings had texture and bite, and piano sounded controlled.

I just learned that the Lightning port is digital out only. I knew it could do digital but I figured it could also do analog because I could hook it directly to headphones with the adaptor. It turns out the adapter itself has a microscopic DAC and headphone amplifier built into it. That means the Lightning to 3.5mm adaptor is actually what’s making the music. The adapter is the source (not the phone) while the phone is like a transport that also provides power to the adapter. 
Ken Rockwell measured the Lightning to 3.5 mm adaptor and found that it measures very well. It has a low output impedance of 1 ohm. It’s got a ruler flat frequency response and very low noise. He said, “This tiny Apple device has better performance and more and cleaner output than many fancier "audiophile" devices I've tested.” (I believe he is referring to portable “audiophile” devices, not home audio.)

While this device probably isn’t going to compete with any of your high end gear, I suspect it can compete with most entry level gear and maybe even some questionably designed mid-tier equipment. If you take into account the price ($9), it is jaw-dropping sound for what you paid.

Has anyone else tried this? Curious to hear what you think. I can tell you it has replaced my entry-level CD player. Hard to compare it to my main CD player (haven’t figured out how to battery power that and my AC power seems to be relatively dirty but that’s a story for another post).
You mentioned Ken Rockwell. That guy is cool and really smart! 

I had a short email discussion with Ken about CD players and audio quality in general a while back. We discussed this article:

CDs on a reference-grade CD player are going to be more accurate than CDs on an entry level player. Why is this so important?! 

More accurate does not necessarily translate to better sound quality in a subjective way. That is, your biased perception of how nice your music sounds. This is what most "audiophiles" are chasing.

As an audio enthusiast, I have had to remaster quite a few tracks that sounded terrible on my reference gear...only to find out later the mastering was done with cheapo speakers in a budget studio. 

A power conditioner is a worthwhile investment. Austere is an amazing value but Furutech makes the best.

Thanks for the feedback. Ken’s article’s are always a fun read. I like his take on CD sound quality. I have found CD (with the right CD player) to be very hard to beat. I will have to look into a power conditioner. I’m wondering if there is a way I could measure my power quality before seeking out any solutions to make sure I’m solving the right thing. 
Just wanted to chime in with another experience I had recently. I hooked up an Apple iPad via a 3.5 mm to lightning adapter and ran the signal to a tube preamp and then on to the rest of my rig. At first, I was not all that impressed until I let everything warm up/burn in. After 20-30 minutes of playing, the sound became very smooth and coherent. Could turn up the volume a lot without sounding harsh in any way. I could very clearly hear instrument harmonics and the low-level detail was very impressive. Bass wasn’t too shabby either.
Just wanted to share my experience for others to hear. If you are looking for some entry-level gear, I think this setup would be very hard to beat. I can’t imagine what could beat this price to performance ratio. Heck, many people have an iPad and lightning cable sitting around collecting dust (or an iPhone in their pocket) - just add a tube preamp (or plug into your existing one). If you are bored and looking to tinker, this is a fun little experience. I guess what I’m trying to say is that this is a cheap and easy way to get upper entry level sound and in some ways (e.g. low level detail) mid-tier performance and it doesn’t seem like very many people know about it. “What?! A $9 lightning adapter ain’t gonna beat my CD player.” I wouldn’t be so sure. My only caveat is that I am listening mostly to classical instrument recordings where low-noise, quiet backgrounds, micro-details, and harmonics are very, very important. I won’t in any way guarantee this will be the best for every style of music. But for the simplicity and value, I can say it’s definitely worth a listen.
I was wondering about this myself. I can use my iPAD as a ROON endpoint and use a lighting plug with a USB end. Plug that into my DAC and it sounds purdy damn good streaming 24/96Khz from Qobuz, Play Youtube video and concerts or stream high rez right from the Qobuz app. The Boulder Phil streamed a live concert the other day and my neighbor ask if I could help them watch it. I knew he had a USB port on his DAC so I just found the concert on his iPAD took over my cord and they watched the concert on the iPAD and listen to it on his main system. You post got me wondering how headphones work that plug into that lighting port and found out that the headphones cord has a DAC in them. Like these
I have tried exactly what you have done but with an Audioquest Jitterbug noise filter attached: iPhone 6s > Lightning to 3.5mm adapter > Audioquest Jitterbug 

It sounds similar to the output from a laptop PC, but I decided to get a Pro-ject Stream Box Ultra S2 streamer (basically a Raspberry Pi with power supplies optimized for lower noise). As much as I wanted the iPhone to sound just as good (because it's always better to have to spend less money), the the Pro-ject streamer sounds quite a bit better. These were my listening notes on the differences I heard.

Adding Jitterbug to Stream Box and Dragonfly Red makes a very clear improvement in resolution. Versus iPhone, the Stream Box is now better in:
  • Broader & more 3-dimensional soundstage
  • Better resolution of complex musical passages: Electric bass in Blue Moon Revisited on Trinity Sessions, Cowboy Junkies & Waltz for Debby, Bill Evans Trio
  • Tonal colors are more evident
  • Notes seem to hang in the air longer. Reverberations continue instead of being cut off.
  • More presence around voices and instruments.
For the 'bits are bits' crowd, I believe the differences are due to jitter and analog noise in the music signal.
Also, just to change up my day and take a break, I just tested this out again. I have a Pro-ject streamer that’s been connected to a Denafrips Pontus II DAC for the last two weeks. I unplugged the USB cable attached to an Audioquest Jitterbug noise filter and plugged both into an Apple iPhone via an Apple Lightning to USB 3 Camera Adapter. The iPhone as a source sounded good, BUT the Pro-ject sounded hands down better in the following ways:
  • The iPhone as a source sounded "fuller", but the Pro-ject as a source sounded bigger with a broader soundstage.
  • Better resolution of complex musical passages: Electric bass in Blue Moon Revisited on Trinity Sessions, Cowboy Junkies & Waltz for Debby, Bill Evans Trio
  • Tonal colors are more evident
  • Notes seem to hang in the air longer. Reverberations continue instead of being cut off.
  • More presence around voices and instruments.
  • Complex rhythms are easier to follow via the Pro-ject. Not so much via the iPhone as a source.
Starting with an iPhone as a streamer is a decent first step if that might allow you to spend more on a DAC. I do think that there are sonic benefits to going to a dedicated streamer for better sound quality if that is an important consideration.
Calvinandhobbes, did you let the system warm-up/burn-in when you switched to the Lightning Connector? When I first fired it up, I wasn't all that impressed. I immediately wanted to go back to the way my system was before. After letting it play for about 30 minutes, it sounded much, much better. 
I didn't let the iPhone warm up the first time I did this, but out of curiosity, I just connected my iPhone to my Pontus DAC and let it play for 30 minutes. I was listening to the new Norah Jones live album release 'Til We Meet Again' with vocals, piano, percussion and acoustic instruments. Key tracks used for comparison were "Those Sweet Words" and "Black Hole Sun". Maybe the music from the iPhone got a little smoother after 30 minutes of playing? I'm not entirely sure. Regardless, the output from the iPhone sounded enjoyable.

I then switched back to my Pro-ject streamer. The sound quality difference was immediately noticeable to me in the following ways:

  • More transparent
  • More open & airy.
  • Better balance between the different instrumental and voice elements of the music
  • Seemed to have a better rhythm and flow to the music
  • Greater variation in tonal color of voices and instruments

Also, I gave the iPhone the advantage of playing back a file stored locally, while the file via the Pro-ject was streamed via Qobuz. The iPhone was also disconnected from both charger and battery.

Also, a correction that I am using the Apple Lightning to USB adapter, not the Lightning to 3.5mm jack adapter as I mentioned in a prior post.
I’m not sure how the Lightning to USB adapter works. Does it send digital or analog audio out of it? The Lightning to 3.5mm audio sends analog out. That’s the one I am using. Very simple signal chain.