Fully Rendered MQA Audio (and DSD Audio) Not Available Through USB-C Port of 2018 iPad Pro

Guys, please sign your names so I know who I am talking to, thanks!

I designed all the DragonFly’s and work with Tidal, MQA, Roon and have a long standing with Apple.

If you are not getting the Purple indicator with Tidal are you setting the streaming options for WIFI and Cellular correctly. Hit “My Collection” (lower right corner), then the “Gear” upper right corner of My Collection and scroll down to Quality->Streaming and set those accordingly.

I am going to purchase a iPad Pro this week. Tried to score one over the weekend a little cheaper under eBay but no luck. Will pick one up from B&H or somewhere reasonable today or Monday.

But just from what you are saying and your DSD experience it seems as though the samples out are being manipulated so that the MQA/DoP information is getting effected some how.

Thanks,
Gordon

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Thanks Gordon for making your position clear! Let me just say that I’m grateful you’re digging into this, you’ll probably have more leverage towards Apple than most of us :slight_smile:
So far I’ve raised the issue to Apple, Tidal and AudioQuest with no luck.
As for the streaming options, I’ve set them correctly to “Masters” in Tidal.app and accordingly in Roon.

I’m sure, once you get an iPad Pro 2018, you’ll have no trouble noticing this behaviour!

Thank you,
Ola

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Gordon, wow nobody better to look into this problem than the engineer of the DragonFly himself! Thanks so much for attacking this for us. It has been an issue with the new iPad Pros since release and exactly as Ola describes in the previous post. I absolutely guarantee you will have no trouble reproducing this issue as soon as you get your hands on the iPad Pro. As Ola says, it happens whether via Tidal or Roon and regardless of dongle (I have tried both Apple and Belkin USB-C to A adapters). I was actually hoping maybe the release of iOS 12.2 yesterday would have fixed the issue but no such luck.

Looking forward to seeing a fix for this soon and thanks again so much for getting involved!

-Dave

All,

It appears that the iPad Pro is not listening to the Asynchronous Feedback Pipe and therefore the DACS are under or over running their internal buffer which makes everything reset.

This is why DoP and MQA are not working on that device. I submitted a bug report and pushed this up the ladder at Apple and they will be able to fix this pretty quickly.
Thanks,
Gordon

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Thank you Gordon.
Regards
Bjarne

That’s what my wife has been saying for the last 20 years about me…

On a more serious note, as an iPad Pro 11 and DragonFly Red owner – thanks for jumping in, @Gordon_Rankin!

Great to hear @Gordon_Rankin!
Many thanks for pursuing this!

/Ola

Great! Thanks!

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@Gordon_Rankin Hey all, I just made an account to post this and add to the number of people with this Issue.

I’ve got an Ipad pro 12.9 (3rd Gen) with USB-C of course and when connected to a dragonfly red (with or without a Jitterbug as well) I also get lots of noise along with the dragonfly switching between two colors as if It wont grab and hold the MQA signal. I’ve even tried 4 different USB-C to USB-A adapters with no luck. It looks like this is already being looking into with the help of some really awesome people!
Just wanted to give my thanks to you all for posting and hoping to see an update (obviously this stuff takes time) when more info is available. Thanks all!

I love the dragonfly so much already! especially hooked up to my PC and car speakers!

-Shane S.

Shane,
We are aware of the problem. I am just trying to find out if this is an MQA Library problem or an Apple problem. I am working with both as I found the real culprit yesterday.

Thanks,
Gordon

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It doesn’t sound like a mqa library problem, as it works perfectly fine on lightning to USB on older iPads and the iPhone but only fails to work on the usb-c based iPad Pro. That sounds to me to be a driver or audio stack problem with the usb-c interface for Apple.

One more piece of data to eliminate it being an mqa library problem. Mconnect can play tidal files but does not decode mqa. On iPhones and ipads other than the usb-c Pro, an mqa decoding dac like explorer 2 will show the blue light. With the usb-c iPad Pro, you get no mqa at just 44.1/48khz. I would say it sounds like a bit perfect problem on that platform.

Ben

Ben,
We are talking about library routines on the IOS side. If both Tidal and Roon experience the same problem on an iPad Pro with USBC then it is probably a library problem. This only happens on the USBC version and not other iPad’s or iPhones.

The USB analyzer traces show the problem. Tidal, MQA and Apple have the traces and they are working on it.

I did realize that Explorer 2 did not get recognized in Tidal and sent that info to Tidal.

Everyone is working on it, should have something soon.

Thanks,
Gordon

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Ben,

I also did bit checks and the interface is bit true. I ran the iPad Pro into a WaveLink (USB->SPDIF) and hooked it up to my Prism dScope III and ran digital tests on it.

Thanks,
Gordon

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@Gordon_Rankin you da man :grinning:

Hi Gordon,

Oh, my misunderstanding. Yes, whatever it was definitely affects iOS as a whole as all apps fail to deliver mqa.

Thanks for tipping them to the explorer 2 problem. It worked with yesterday’s build 1946. Finally I can use mqa on the iPhone in its full blown form. I had a pain working with their support person as they couldn’t seem to understand the problem and we were going in circles. I’m so glad you were there to relay the information.

Hopefully the usbC problem gets fixed soon. Can you help explain a bit how mqa works on a usb dac? I thought the Dac receives a bit perfect digital bitstream and if it seems the mqa information in it, it can decode it. So if you are seeing a bit perfect bitstream in the usbC implementation, what would cause the mqa to not be working?

Thanks,
Ben

DSD also fails on the USB-C ipads. DSD plays, but with severe white noise in the background. Perfectly fine on iPhone 10XS. I tried every DSD playing app in the app store.

I am not sure what that problem is. I have verified that the interface is bit true but I have not done any DSD in the testing. I take it this is DoP DSD at either 64 or 128 as I don’t think IOS does sample rates above 384.
Thanks,
Gordon

Hi Gordon,

How’s the progress on this? Apple know how to fix it yet?

Thanks,
Ben

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I just upgraded my iPad Pro to iOS 12.3 and they [Apple] seem to have fixed this now!
MQA tracks through Roon plays without problems with steady purple light on the AQ DragonFly.
DSD gets downsampled to appropriate PCM sample rate and plays also!

MQA also works through the TIDAL iOS app!
Update: Tested with my Chord Mojo and I can confirm that DoP now works with that device!

Thanks @Gordon_Rankin

/Ola

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