[Xp-Audio]

   
Correct, UAPP not required. Get a Dragonfly 1.2 any day now, will be interesting to see if any devices can manage that without UAPP.

The DragonFly does not currently work with older Xperia products, and I have asked the team to investigate why.
 
With the new Z2 and T2 it "works" to the extent that we can play any supported sample rate and it sounds good. However, currently Android does not support volume control over USB, and we have not managed to resolve that for Z2 and T2.
 
The result is that DragonFly plays at some "default" level which is reasonably loud, but depending on the sensitivity of your headphones and your personal preference, that might be too loud or too low for you. For myself, I prefer the easy portability of the DragonFly in most use cases over the control I get of the volume in the FiiO E17 which I also use. Resolving the volume control is in our backlog, awaiting investigation. I cannot comment on whether we will solve it or not, so if you like the DragonFly, you should be aware of this situation.

 

[SV_huMMer]

  The DragonFly does not currently work with older Xperia products, and I have asked the team to investigate why.
 
With the new Z2 and T2 it "works" to the extent that we can play any supported sample rate and it sounds good. However, currently Android does not support volume control over USB, and we have not managed to resolve that for Z2 and T2.
 

 
I use M2Tech HiFace DAC - which has no physical volume control neither. However, UARP/UAPP give you the ability to adjust volume control (albeit it is far from perfect), so Android limitations can be circumvened. However, I could not use the DragonFly neither - but for other reasons than volume control.

 

[swab]

I haven't got the foggiest about Android audio frameworks or USB standards, but if I connect my new Stoner Acoustic UD110v2 to OTG cable, plug it into my Moto G (KitKat 4.4.2 ; version 174.44.9), I get audio out of the UD110, at a default line out level, for all apps (Spotify, Google Play Music, Youtube etc.).
 
This level of audio output is too "hot" for my poor old Fiio E5 amp, resulting in audible distortion during playback at the very loudest passages of music, where there is loud low frequencies etc. Ringtones, alarms and notifications all come through the phones speaker. If I launch USBAPP (trial), any mp3's I have on the device will output from the DAC, and I am able to use the apps volume fader to adjust the volume, thus limiting any distortion in the Fiio E5. It sounds really good to my ears. All mp3's are 16 bit/44100. The only issue now is that if I go back to another app after having used USBAPP, the audio from the other app comes out of the phones speaker (as opposed to the DAC). It will require a reboot to get the other apps audio routed through the DAC again.
 
However, once I reboot the phone with the UD110 still attached, once booted I can control the volume output from the DAC to the Fiio E5 using the phones volume controls (physical hardware buttons & software slider) for Spotify, Play Music, Youtube etc. All the phones audio will be routed through the DAC. I could even dispose of the Fiio E5 and comfortably power my Blox M2C earbuds directly from the UD110's line out. Consensus however dictates this is not advisable, so I route the audio through the Fiio E5, and set the phones volume to 60-70%, thus limiting any distortion. If I set the phones volume to 90-100%, the distortion returns. Once USBAPP is launched it will work as handsomely as before. Once I quit or switch from USBAPP however I get no audio from any other app, or any ringtones etc. Rebooting without UD110 connected will restore to default audio ; rebooting with UD110 connected, on board volume control of all apps is reinstated.
 
I have verified that the DAC is not producing the distortion by running Spotify audio from the Moto G and my wifes iPhone 5 (iOS 7) out to my Denon Ceol Piccolo through the UD110, to analog line input. In fact the audio sounds sweetest from the iPhone source, but even the Moto G betters the Piccolo's built in Spotify source. For reference, I used Aphex Twins Girl/Boy as my test track (how very scientific eh). I'm fairly happy that I have found a very inexpensive DAC that I can use at home and away, but am still a bit confused/frustrated as to the whys and what nots surrounding Motorola/Android implementation of audio over USB.
 
A notification for another system update for the Moto G (176.44.1) appeared on my phone today. This update resolves, amongst other things, support for external USB drives connected by OTG (nice). I will await confirmation from Motorola that audio via USB will not be broken by this new update before I will update. Unless anybody else can verify the update is good to go here first (are you listening jellofund).

 

[swab]

I forgot to add that if I disconnect the UD110, and reconnect, the previous audio state will recommence. Also note that one cannot reinstate the default audio profile for the Moto G if one has rebooted with the UD110 attached unless one reboots the phone again with nothing attached.

 

[jellofund]

 
A notification for another system update for the Moto G (174.44.1) appeared on my phone today. This update resolves, amongst other things, support for external USB drives connected by OTG (nice). I will await confirmation from Motorola that audio via USB will not be broken by this new update before I will update. Unless anybody else can verify the update is good to go here first (are you listening jellofund).

 
Sorry the update hasn't been rolled out here yet so haven't tried it. After the recent issues with OTG support I'll probably hold off until it's 100% certain they didn't break more than they fixed 

 

[deadie]

With my LG G2, I'm able to OTG plug-n-play (both local and streamed audio) with the Audioengine D1, but not with the Dragonfly v1 nor the HRT Music Streamer II.
 
Since this is a phone specific topic, I'll just mention that my new Samsung Galaxy Tab Pro 10.1 works with all three aforementioned DACs right out of the box, no additional drivers / apps required.  
 
More details in this thread.  http://www.head-fi.org/t/558952/tablets-to-external-usb-dac/30#post_10308161 

 

[James1776]

   
Correct, UAPP not required. Get a Dragonfly 1.2 any day now, will be interesting to see if any devices can manage that without UAPP.

My Xperia Z with a dragonfly v2 works great with USBAPP and not at all without the app...

 

[Xp-Audio]

 
My Xperia Z with a dragonfly v2 works great with USBAPP and not at all without the app...

Yes, as I wrote earlier today, the DragonFly does not work with any previous Xperia devices, only with Z2 and T2.
 
This afternoon we also confirmed my suspicion that this is due to the Dragonfly requiring 16-bit data to be padded to 24bits. I am not sure why some DAC's have that behaviour, but it is definitely a dealbreaker for Android devices which are using stock Android USB.
 
I am trying to convince my colleagues to resolve that in some future update, but as ever it is a question of priorities.

 

[Theogenes]

 
Well, I wonder if the real trick is the AirStor app.  If it works with a standalone wireless hard drive like the Seagate Wireless Plus 1TB drive, that's exactly what I'd be looking for.  Anyone know any of the thumbdrive-size USB dacs work with the Nexus 5 (or the Samsung Tab Pro 10.1)? I know the dragonfly doesn't.

 
To my knowledge, AirStor is the application for Apple, and MobileFun is the app for Android. The Wireless Plus has its own app, I believe. Also, with the use of the Ravpower, you wouldn't need to get a Wireless Plus, you could get pretty much any USB-enabled hard drive you want and use it. You could also use it with a thumbdrive, of course (it has a card reader built-in as well), but IMO using a full-sized hard drive is even better than a thumdrive. YMMV. 

 

[jared basshead]

I dont know if anyone has already mentioned it or not but Lenovo K900 needs USBARP to interwork with USB DAC. Plug n play would have been nice I know. Just bought it looking at the design aspect, it looks so nice and premium. But yeah it needs USBARP.

 

[jellofund]

@ swab
 
The update popped up later in the day yesterday.
 
Used my Wife's Moto G as a guinea pig and went ahead and installed it. USB audio still seems to be working fine, so going to update mine shortly

 

[swab]

  After much umming and ahhing about which dac/amp to get for my phone I decided upon the JDS Labs C5D:
 

 
Only received it last night (kudos to Headphoniaks in Spain for the great service & stellar packaging job) so only been able to use it for a few hours, but so far I'm really very pleased with it. I wanted something that would give me comparable SQ to my home O2 & ODAC set up and early impressions are that it more than holds its own 

 
Quick update: I mentioned earlier that my ODAC worked fine with my Moto G but the phone's volume control was disabled. I've since discovered that volume control does in fact work, but I need to power off the phone beforehand or it doesn't detect the ODAC properly - had previously just left the phone in stand by / sleep mode.

 
Hey jellofund,
 
I hope you don't mind me asking a few questions regarding the C5D and Moto G. It would go some way toward helping me decide on whether I should stick or switch with the UD110 + headphone amp combo setup I'm using currently.
 
 
1. Is it truly plug and play ? As in the phone reverts to its default audio profile before and after connection and disconnection of the OTG without needing to restart phone.
 
2. All other audio (speaker/microphone/earpiece) works as normal while DAC is connected and ouputting audio i.e. the phone is functioning as a normal phone should.
 
3. Do you ever experience any distortion/artifacts in the audio signal being output by the DAC ?
 
4. Can you switch from "any other" audio app to USBAPP and back to "any other" audio app and still get audio in your phones from "any other" audio app without having to restart the phone ?
 
 
And I'd greatly appreciate if anybody else here can volunteer any first person experience/knowledge of matching the UD110's with a suitable sub €/$100 amp, I fear my Fiio E5 is not a good match for the UD110's line out level.
 
 
Thanks for listening
swab

 

[swab]

Thanks much for the heads up on the update jellofund, going to update today too. Nice to have the OTG external drives back.

 

[Xp-Audio]

  A small portable USB hub you mean, right? 
 
This is an old trick, and I am not sure it can somehow be related to warranty...
 
Another question: can you share with us the power limitations for OTG mode on Z2? I.e. how much current can the phone provide, before we see the deadly "The connected device requires too much power" message?

According to our expert, we cut off power and put up that message when the total current exceeds 500mA. This is in accordance with the USB 2.0 specification. 

 

[James1776]

  Yes, as I wrote earlier today, the DragonFly does not work with any previous Xperia devices, only with Z2 and T2.
 
This afternoon we also confirmed my suspicion that this is due to the Dragonfly requiring 16-bit data to be padded to 24bits. I am not sure why some DAC's have that behaviour, but it is definitely a dealbreaker for Android devices which are using stock Android USB.
 
I am trying to convince my colleagues to resolve that in some future update, but as ever it is a question of priorities.

I am experiencing an intermittent problem. More often than not I have to reboot the phone before it recognizes the dragonfly, though it does give me the initial request for permission in USB Audio Player pro and I check the box authorizing the device. Up pops the correct screen with my music BUT, it will not play the files. Rebooting the phone and trying again seems to work.