Android tab as digital transport!

Santy

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Hey guys

The story goes like this. I had an extra pair of active monitors bought keeping a secondary setup in mind. Obviously, a second system at my home was not must to have but nice to have. After my recent DAC upgrade the poor Caiman had to be shelved without a digital transport to feed it.

What I needed was a music/ media player that can play FLAC/MP3 on SPDIF/ USB audio but I was not keen to spend too much on such a transport. I was exploring many options for the last two months though not desperately.
- SBT- not available easily these days but quite expensive if you consider that the DAC part of it is redundant (also, my gatorized Caiman is slightly better than SBT, IMHO)
- Ipod Dock problem is I have only one i-device and its my own phone. Many docks have no digital out and the ones with it are quite expensive. Again the DAC part of it is redundant in my requirement.
- Media Player something like Asus oplay would be great but then I need a display. Switching on a 32" LCD for casual music was not justified.
- A Bluetooth receiver (to work with tab/mobile): still not as good as a hi-res digital source
- A mini laptop something powered by atom processor. Quite expensive; more than 14k? It will be underutilized too.

I had Nexus 7 tab bought for a ridiculous price recently mainly for my browsing tasks and to keep my little daughter engaged happily with some android games. Thinking about using it as a digital music player, there are a few discussions on the net to get USB audio out of it. But I had to flash it. For me rooting was quite a challenge backup, custom ROM, kernel, CWM, recovery, warranty void, bugs, roll back, reset. suddenly there were many perilous words flashing in my mind. Then I came across this app in Play store; USB Audio Player PRO [ quick disclaimer: you know what comes here]

It claims to output USB audio out of an android device without rooting. There was a free (trial) version available to test it out. I installed it, connected the DAC through the OTG cable and started the app. It showed an error (no device found). I rebooted the tab and the USB audio device was successfully detected by the app and it started to play. Wow. The tab with a gorgeous 7 display suddenly became a crisp digital music player. I could not believe I got it up and running within 10 min of deciding to try this app. It even plays 24 bit songs. Impressive! The app has some basic features, playlists, shuffle, gapless playback, upconversion etc, The UI was quite simple but enough for me. It supports digital volume control which you can bypass in the settings. The free version is limited to 20 min of playback and some other restrictions but it did not take much time for me to decide to buy the full version at ~ Rs. 600. Its 100% worth for someone like me looking for a quality digital transport from a device that does a lot, lot more than just bitstreaming music.

The audio quality is great but I do not wish to assess more since I am kind of spoilt by my DAC upgrade and that the experiment was done with my old DAC. But it is certainly clean. I guess I am not really worried about power supply, EMI, CPU load, background services, tweaks, latency etc. that superfluously haunts PC users. The songs are playing smoothly, effortlessly and continuously as I write this article. The battery does not seem to be losing its juice quickly either.

I am quite excited to have setup a nice digital music player that put my spare DAC to its intended use. The excitement is multiplied when you know how much more you can do with an android tab that was bought for about 9k or so.

The downside: You are limited by the device storage for your music library (atleast in Nexus 7). The app keeps asking if it should reserve the USB device every time it starts. It doesnt work with DACs that require proprietary drivers. Not so great UI and not possible to stream music. But these are pretty understandable.

The app page states that it is tested with many DACs like Audiolab M-Dac, Dragonfly, Benchmark, CA DacMagic, FiiO, HiFimeDIY, HRT, iFi iDAC, M2TECH hiFace, MF V-DAC, NuForce uDAC, ODAC, etc

IMG_0649_zps1e89b842.jpg
 
Very nice. It seems like an ideal use for an android tab, or even phone --- so long as the USB host with OTG thing is supported and works.

But... now you have to buy your daughter another tab! :lol:
 
@Santy
Congrats on the setup...
Regarding extra storage, one of my friends has used the same OTG cable to connect an external pen drive (32gb) with his Nexus 7 and it worked with this app without rooting it. So in your case I think you need to get a USB Hub (preferably powered) and connect both the DAC and external HDD and you are good to go. He has not tried a 500gb/1TB HDD but looking at online reviews it seems that it should work.
 
Santy,

Interesting. I checked my daughters tablet and it does have Micro HDMI out. If I can get audio + video out of it, then it can be a nice little device and I will have to get one.
As for storage, I can access NAS through android.
 
Very nice. It seems like an ideal use for an android tab, or even phone --- so long as the USB host with OTG thing is supported and works.

Yes I guess it would work on some android phones too.

@Santy
Congrats on the setup...
Regarding extra storage, one of my friends has used the same OTG cable to connect an external pen drive (32gb) with his Nexus 7 and it worked with this app without rooting it. So in your case I think you need to get a USB Hub (preferably powered) and connect both the DAC and external HDD and you are good to go. He has not tried a 500gb/1TB HDD but looking at online reviews it seems that it should work.

Thanks Manniraj. I bought this app and it did work with JB. I played a couple of movies out of pen drive. But it is not working after KK upgrade. OTG and device are detected but the Nexus media importer app simply is stuck at 'Waiting for media' message. And are you sure this basic tab would support more than one USB device at a time? Will try it out sometime.

Santy,

Interesting. I checked my daughters tablet and it does have Micro HDMI out. If I can get audio + video out of it, then it can be a nice little device and I will have to get one.
As for storage, I can access NAS through android.

Yes tabs with micro-hdmi is pretty straight forward. Can simply connect to a TV or AVR and use it as media player. The app says it shares 'android playlist'. Not sure what it means. The app displays all tracks on inbuilt memory. If it could show the tracks on NAS, it will be great.
 
@uttam

I think you would normally have a USB type A (male) to type B (male) cable to connect your DAC. This connection would need the source end to have a female type A adapter which is what the OTG cable offers. I hope I am right here.
 
Hey guys

But it is certainly clean. I guess I am not really worried about power supply, EMI, CPU load, background services, tweaks, latency etc. that superfluously haunts PC users. The songs are playing smoothly, effortlessly and continuously as I write this article. The battery does not seem to be losing its juice quickly either.

While I appreciate the really nice info, the above is not true at all. Even android has background services and the latency issues on android devices are at least a factor of five worse than a properly setup PC. Also Cortex A9/A7 processors inside most tablets are not the most powerful and if there was an issue of a cpu not having enough grunt to play music in real-time, this is it.

Remember that android under the hood runs a linux kernel with a Java like JIT interpreter system. Yes you can always write native modules in C++ but I'm not sure how many audio players utilize the same. Plus if the app uses Skia to render graphics (as it appears from the image), that will tax the CPU too since anything that goes through skia is not gpu accelerated. So the issues that persist on a normal PC exist on android as well - only in a substantially worse manner. You are better off running linux on a dual core atom than using android on an arm cpu.
 
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While I appreciate the really nice info, the above is not true at all. Even android has background services and the latency issues on android devices are at least a factor of five worse than a properly setup PC. Also Cortex A9/A7 processors inside most tablets are not the most powerful and if there was an issue of a cpu not having enough grunt to play music in real-time, this is it.

Remember that android under the hood runs a linux kernel with a Java like JIT interpreter system. Yes you can always write native modules in C++ but I'm not sure how many audio players utilize the same. Plus if the app uses Skia to render graphics (as it appears from the image), that will tax the CPU too since anything that goes through skia is not gpu accelerated. So the issues that persist on a normal PC exist on android as well - only in a substantially worse manner. You are better off running linux on a dual core atom than using android on an arm cpu.

May be true and I am not a techie but why not try the android version of XBMC which has the hardware acceleration of DXVA I believe if I am not wrong. This should work fine without taxing the CPU much.
 
May be true and I am not a techie but why not try the android version of XBMC which has the hardware acceleration of DXVA I believe if I am not wrong. This should work fine without taxing the CPU much.

Yes that potentially might be better but then why not run xbmc directly on linux itself. Makes way more sense to me. Android is unnecessary evil in this chain.
 
Thanks Manniraj. I bought this app and it did work with JB. I played a couple of movies out of pen drive. But it is not working after KK upgrade. OTG and device are detected but the Nexus media importer app simply is stuck at 'Waiting for media' message. And are you sure this basic tab would support more than one USB device at a time? Will try it out sometime.

Me and my friend brought the Nexus 7 2012 model last month during the Flipkart sale for 8k. So he has got automatically upgraded to KK and the OTG cable works fine with the media importer app with his 32gb pen drive. Still I am not sure whether a USB hub works but if it works then I am pretty sure that a powered USB hub will give better results.
 
Yes that potentially might be better but then why not run xbmc directly on linux itself. Makes way more sense to me. Android is unnecessary evil in this chain.

The reason I can think of is that Santy and probably majority of the people would like to run a media device especially music/movies to be as minimal as possible and the DIY PC will need to have some sort of a display if not using an app on a mobile.
 
A lot of sons and daughters are going to curse Santy for this :)

Looks like an android tab is quite popular for kids nowadays (even I am one of the culprit here). Knowing that one can use it as a portable music player, someone who is NOT a hardcore audiophile or a DIY kind of a guy, would definitely be looking at this option to play the occasional music.
 
A lot of sons and daughters are going to curse Santy for this :)

Looks like an android tab is quite popular for kids nowadays (even I am one of the culprit here). Knowing that one can use it as a portable music player, someone who is NOT a hardcore audiophile or a DIY kind of a guy, would definitely be looking at this option to play the occasional music.

Yes definitely I have to persuade my daughter to give me the tab to listen to Internet radio by handing over my laptop :lol:
 
While I appreciate the really nice info, the above is not true at all. Even android has background services and the latency issues on android devices are at least a factor of five worse than a properly setup PC. Also Cortex A9/A7 processors inside most tablets are not the most powerful and if there was an issue of a cpu not having enough grunt to play music in real-time, this is it.

Remember that android under the hood runs a linux kernel with a Java like JIT interpreter system. Yes you can always write native modules in C++ but I'm not sure how many audio players utilize the same. Plus if the app uses Skia to render graphics (as it appears from the image), that will tax the CPU too since anything that goes through skia is not gpu accelerated. So the issues that persist on a normal PC exist on android as well - only in a substantially worse manner. You are better off running linux on a dual core atom than using android on an arm cpu.

Well, I never claimed that Android based source is better than PC. I can't say so because I don't know.:p But its just that I cared less as the tab was a cheaper alternative, serves my purpose as a secondary source and I am not highly particular about its quality as digital transport (mostly used for casual listening by me and by my family members). Rather than comparing a tab with a PC, if the tab was bought for convenience and if it works for digital audio, then why not. Its a lot, lot more clutter free if you come to think of it (greener too). Moreover a good async DAC should take care of jitter if at all that is high on a tab, to a good extent.

Having said that the EMI I believe is much stronger in a PC with powerful PSU whereas the tab runs on clean battery power. I am not sure why you think a tab with 1 GHz quad core CPU & 1 GB RAM is not powerful enough for an audio playback. The Tegra processor is powerful too and takes away lot of display load from the CPU. I have run 1080p movies without a glitch so I don't see why it should struggle for audio playback.

You must check this report ARM posts Cortex-A9 vs Atom performance video, Intel should be worried | Chips | Geek.com. It shows an ARM cortex A9 fired at just 500Mhz without a GPU support gives a close fight to Atom processor clocked at 1.6 Ghz. Not that I understand the technicalities but I think a quad core CPU clocked at 1 Ghz and supported by a Nvidia GPU would not have any issues in serving real time audio processing. And then you can keep the tab also free from unwanted apps/ services, the way you do with PC if that is supposed to give a better performance (or peace of mind). ;)

I reiterate that this is not the best digital transport but just an alternative that could suit many on a budget and requirement (esp. for secondary system).
 
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Nice research. However, a Raspberry Pi with XBMC beats all Android based solutions.

That route is cheaper too.

Yes I forgot to mention that it was an option I considered (along with Cowon pmp with SPDIF out) but then you need a display for the Pi right? ;)

Knowing that one can use it as a portable music player, someone who is NOT a hardcore audiophile or a DIY kind of a guy, would definitely be looking at this option to play the occasional music.

Yup, that's the idea. A cheap dac like HifiMeDIY with the tab would sound great according to me.
 
+1 to Santy, I am in the process of may be doing the same for my bedroom setup. Its clean clutter free and less power consumption and space.
 
good discussion. Does anyone know of any bit stream app for android(aka. arm processors)?

would appreciated if someone can suggest an app similar to Jriver/JPLAY for android - could not find one that is capable of bit streaming.
 
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