Android phones and USB DACs

DanBa · Jul 5, 2012 at 8:29 PM

An Android 4.1 Jelly Bean device can have:
. a standard USB audio out capability (or USB audio host capability), or/and
. an Android-specific USB audio out capability (or USB audio accessory capability).

An Android device that has the standard USB audio out capability can interwork with standard/legacy USB DAC.
A standard/legacy USB DAC can be a self-powered device, or a bus-powered device.
Some bus-powered USB DAC like the Objective DAC (ODAC) can be powered by some Android smartphone like the Samsung Galaxy S III.
If a bus-powered USB DAC requires too much power, it should connect to an Android device via a self-powered USB hub.

An Android device that has the Android-specific USB audio out capability should interwork with a USB DAC of a new type.
Such a USB DAC must provide power to an attached Android device.

The standard USB audio out mode is specified in Android specifications:
http://developer.android.com/guide/topics/connectivity/usb/index.html
http://developer.android.com/guide/topics/connectivity/usb/host.html
http://developer.android.com/reference/android/hardware/usb/UsbConstants.html
"int USB_CLASS_AUDIO: USB class for audio devices."
The Android 4.0 smartphone Samsung Galaxy S III can interwork with standard/legacy USB DAC like ODAC or FiiO E7.

The Android-specific USB audio out mode is just added in Android specifications:
http://developer.android.com/reference/android/hardware/usb/UsbAccessory.html
"Android Open Accessory Protocol 2.0 includes optional support for audio output from an Android device to an accessory. This version of the protocol supports a standard USB audio class interface that is capable of 2 channel 16-bit PCM audio with a bit rate of 44100 Khz. AOA 2.0 is currently limited to this output mode, but additional audio modes may be added in the future.
To enable the audio support, the accessory must send a new USB control request: SET_AUDIO_MODE"
http://developer.android.com/tools/adk/aoa2.html#audio-support

Hopefully, Google and Android device manufacturers will enable the standard USB audio out mode along with the Android-specific USB audio out on their stock Android 4.1 devices. It should be available to everyone, and not only for a few ones hacking their Android device.

One of the ways to let them know that is to vote for the Google issue "Enable (standard) USB audio":
http://code.google.com/p/android/issues/detail?id=24614&sort=-stars&colspec=ID%20Type%20Status%20Owner%20Summary%20Stars

And please ask around.

analogue 3 · Jul 7, 2012 at 3:03 PM

Quote:

anathallo said:
$99 is for 4 gb of internal storage I believe - it's $169 or something for 16gb.

What's with bumping up the price by 70% for a 12gb increase in internal memory? Is flash/emmc really that expensive?

I know for a fact that these much touted Wolfson DACs which quality PMP manufacturers like Cowon use only cost $3 each. Why weren't ALL pmps and smartphones using them all along since they were so cheap? Samsung actually produce their own emmc, so why wouldn't they put 64gb emmc in their galaxy players? Rather than crippling it as a viable desktop replacement source (using usb digital audio out when it's enabled to use with your desktop DAC/Amp setup) with just 8gb, 16gb capacities?

I know when I'm at work, I take pride in doing the best possible job so it reflects well for my organization. So why are these millionaire/billionaire manufacturers often releasing devices with obvious avoidable flaws which just reflect poorly on their own imagination/creatively and technical skills.

Example of an obvious and avoidable flaw:
Sony release a 'droid pmp in 2012 but don't include micro sd??? What an stupid oversight. I can see this happening with sd card sots in portable devices a decade ago, but micro sd expansion should be an obvious feature in a 2012 android PMP.

DanBa · Jul 7, 2012 at 9:02 PM

Quote:

mikeb123 said:
http://pastebin.com/8jqgKnaB
http://pastebin.com/Hh2jCJqq

Here you go.

What happens is I get the USB Connected or Disconnected information in the notification bar, the E17 gets a lock and even when playing sound out through speaker I connect it in and it still plays like I had just inserted headphones or a dock.

So its just the issue of the kernel not switching over I suppose.

It's like getting to 3rd base then finding out shes saving herself for marriage. Haha

The FiiO E17 provides information about itself in data structures called descriptors.
Using these data, the Samsung Galaxy S III can properly drive the FiiO E17.
Apparently, the E17 interface descriptors are buggy:

<4>[ 1040.806786] c0 usb 2-1: config 1 has an invalid interface number: 3 but max is 2
<4>[ 1040.806910] c0 usb 2-1: config 1 has no interface number 2

A more detailed lsusb output should confirm if the patch proposed by an ALSA expert to read the E17 descriptors in a tolerant way can fix the interface descriptor issue.
http://comments.gmane.org/gmane.linux.alsa.devel/96433

<7>[ 1040.828405] c2 usb 2-1: adding 2-1:1.0 (config #1, interface 0)
<7>[ 1040.853342] c0 usb 2-1: adding 2-1:1.1 (config #1, interface 1)

If the FiiO E17 interfaces 0 & 1 are sufficient to allow the interworking, it seems that the FiiO E17 -Samsung Galaxy S III link is disconnected following some power issue (E17 requires too much power from the Samsung?):

<7>[ 1026.336388] c1 s5p-ohci s5p-ohci: GetStatus roothub.portstatus [0] = 0x00030100 PESC CSC PPS
<6>[ 1026.336506] c1 usb 2-1: USB disconnect, device number 7 by hub_thread+0x428/0x1478

#define RH_PS_PPS 0x00000100 /* port power status */
https://github.com/sgs3/GT-I9300_Kernel/blob/master/drivers/usb/host/ohci.h

If it is the case, the E17 should be linked to the Samsung through a powered USB hub:
http://www.head-fi.org/t/587912/fiio-e17-alpen-first-impression-final-thought/3510#post_8407505
http://www.amazon.com/s/ref=nb_sb_ss_i_0_7?url=search-alias%3Daps&field-keywords=powered+usb+hub&sprefix=powered%2Caps%2C390

The Fiio E17 configuration parameter "USB CHarGe On / Off" should be properly set:
http://www.head-fi.org/t/587912/fiio-e17-alpen-first-impression-final-thought/930

The FiiO E17 could be used as an amp of the Samsung Galaxy S III:
http://forum.xda-developers.com/showpost.php?p=27604946&postcount=449
http://www.amazon.co.uk/gp/product/B003QADH9C/ref=oh_details_o00_s00_i00

Samsung Galaxy S III > digital audio stream >> USB DAC "Dynamode 7 Channel USB 2.0 Sound Card" >> amp FiiO E17 >> headphones

Anathallo · Jul 8, 2012 at 8:09 AM

Quote:

analogue 3 said:
What's with bumping up the price by 70% for a 12gb increase in internal memory? Is flash/emmc really that expensive?

My mistake - the 16gb version is $149. Only a 50% increase

.

Also, yes, I would think flash memory is the most expensive component. You also double the RAM with the price increase. I think it's worth it - if the damned thing ever even makes it to market.

Another alternative:

http://www.engadget.com/2012/07/05/archos-raids-the-periodic-table-for-new-line-of-android-tablets/

And the Archos tablets will DEFINITELY make it to market - probably going to wait for the 7" version, though, as it will almost definitely be cheaper.

sluker · Jul 9, 2012 at 1:44 AM

Take a look at all of the recently released android phones and tablets (with the exception of the Nook), none of them have a mico SD card port. Expanding your memory is not an option on the new generation of android devices. This is more than likely a design decision driven by the requests of phone carriers, who generate significant revenues when subscribers exceed their data plans and/or increase their data usage due to content streaming instead of watching/listening the content stored on the device.
In fact most prior generation devices contain/contained SD card slots.
Quote:

analogue 3 said:
Example of an obvious and avoidable flaw:
Sony release a 'droid pmp in 2012 but don't include micro sd??? What an stupid oversight. I can see this happening with sd card sots in portable devices a decade ago, but micro sd expansion should be an obvious feature in a 2012 android PMP.

Achmedisdead · Jul 9, 2012 at 7:49 AM

Quote:

sluker said:
Take a look at all of the recently released android phones and tablets (with the exception of the Nook), none of them have a mico SD card port. Expanding your memory is not an option on the new generation of android devices. This is more than likely a design decision driven by the requests of phone carriers, who generate significant revenues when subscribers exceed their data plans and/or increase their data usage due to content streaming instead of watching/listening the content stored on the device.
In fact most prior generation devices contain/contained SD card slots.

Samsung Galaxy Note, and Galaxy S3, both have microsd slot. The Galaxy Tab 2 7.0 also has a microsd slot.

Anathallo · Jul 9, 2012 at 8:25 AM

Quote:

achmedisdead said:
Samsung Galaxy Note, and Galaxy S3, both have microsd slot. The Galaxy Tab 2 7.0 also has a microsd slot.

Not to mention the Acer Iconia, Asus Padphone, Transformer series, the Archos tablets I mentioned, plus almost every single cheap chinese tablet out there. And that's not even mentioning the Android PMPs that have them.

The majority of devices that DON'T have expandable memory are the nexus devices because of the way Google wants to shape memory speed and partition mapping in the OS on those devices.

a_tumiwa · Jul 10, 2012 at 2:18 AM

i have S3, ibasso D12, usb otg, but no sound on my earphones.
is there any setting to make it work?

DanBa · Jul 10, 2012 at 3:32 AM

It's strange.
t0tor0 reports that iBasso D12, a self-powered USB DAC, works with S3:
http://www.head-fi.org/t/614111/finally-digital-out-for-galaxy-siii/15#post_8498377

Does your USB cable allow you to use a USB mass storage device?

a_tumiwa · Jul 10, 2012 at 8:00 AM

hi DanBa,
thanks for your pointed out about "usb cable" , i thought all usb cables are same, i tested other usb cable (4 in total) , and only 1 worked

actually how to identify which usb cable should work and not work by physical design?

thanks again for your help.

DanBa · Jul 10, 2012 at 11:15 AM

A Samsung Galaxy S III with a Micro-A plug inserted can operate as a USB host (i.e. a USB host-enabled Samsung Galaxy S III can interwork with a standard USB peripheral like a standard USB DAC iBasso D12).
A Samsung Galaxy S III with a Micro-B plug inserted will operate as a USB peripheral.

Micro-A plug: The ID pin shall be connected to the GND pin.
Micro-B plug: The ID pin is not connected.

http://193.219.66.80/datasheets/usb_20/Micro-USB_final/Micro-USB_1_01.pdf

chazman1117 · Jul 10, 2012 at 12:48 PM

I have a Galaxy Nexus running Jelly Bean and I have had no luck in getting my FiiO e7 to run.

DanBa · Jul 10, 2012 at 2:38 PM

It was expected.

A stock Jelly Bean powered Galaxy Nexus should be able to interwork with an upcoming Android-specific USB audio out-capable USB DAC, like the Gear4 speaker dock, that acts a USB host (and the Galaxy Nexus as a USB peripheral).
http://www.engadget.com/2012/06/30/gear4-speaker-dock-supports-usb-audio-for-jelly-bean-at-google-i/

Galaxy Nexus operating as a USB peripheral > digital audio stream >> Android-specific USB DAC "Gear4 speaker dock" operating as a USB host > Gear4 speaker dock’s amp > Gear4 speaker dock’s speakers

Anyway, the Android-specific USB audio driver is included in the Jelly Bean kernel source code of the Galaxy Nexus:
https://github.com/edoko/Air_Kernel_for_GN/blob/master/drivers/usb/gadget/f_audio_source.c#L2

2 * Gadget Function Driver for USB audio source device
4 * Copyright (C) 2012 Google, Inc.

43 .bInterfaceClass = USB_CLASS_AUDIO,
44 .bInterfaceSubClass = USB_SUBCLASS_AUDIOCONTROL,

308 .bInterfaceClass = USB_CLASS_AUDIO,
309 .bInterfaceSubClass = USB_SUBCLASS_AUDIOSTREAMING,

The standard USB audio driver is also included in the Jelly Bean kernel source code of the Galaxy Nexus:
https://github.com/edoko/Air_Kernel_for_GN/blob/master/sound/usb/card.c

2 * (Tentative) USB Audio Driver for ALSA

174 if ((altsd->bInterfaceClass != USB_CLASS_AUDIO &&
175 altsd->bInterfaceClass != USB_CLASS_VENDOR_SPEC) ||
176 altsd->bInterfaceSubClass != USB_SUBCLASS_AUDIOSTREAMING) {

692 .bInterfaceClass = USB_CLASS_AUDIO,
693 .bInterfaceSubClass = USB_SUBCLASS_AUDIOCONTROL }

a standard USB audio-enabled Galaxy Nexus operating as a USB host > digital audio stream >> standard USB DAC like FiiO E7 operating as a USB peripheral >> amp >> headphones

It’s up to us to require Google to enable standard USB audio:
http://code.google.com/p/android/issues/detail?id=24614&sort=-stars&colspec=ID%20Type%20Status%20Owner%20Summary%20Stars

DanBa · Jul 12, 2012 at 4:11 AM

jakenz · Jul 12, 2012 at 9:51 PM

Success! My S3 confirmed to work with the Headroom Total Bithead DAC & headphone amp.

S3 > USB out > Bithead DAC / Bithead Amp > headphones

Works whether the Bithead is set to run on its own batteries (4 x AAA) or set to run 100% USB powered. The latter is a bit of a surprise as this means the S3's USB out is powering both the DAC and amp sections of the bithead, though it does seem to chew through the S3's battery that way. It might be my imagination but I think the S3's battery remaining % does seem to be dropping a fraction faster than normal (~+10-20%) even with the former scenario (Bithead on battery).

Good news anyway, though now I need to make the call of whether I'm game enough to take this slightly cumbersome gaggle of boxes and cables with me to the gym...

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