Android phones and USB DACs
Jan 20, 2013 at 12:54 PM Post #1,411 of 9,526
Now, if only it wasn't two weeks away from anyone.
 
Jan 20, 2013 at 2:04 PM Post #1,412 of 9,526
question for DanBa and other android gurus.  I have an sgh-t999 (TMO s3) and wonder if it is worth rootiing it just too get voodosound support?  Does it really improve the sound, and does it work for usb out as well as the headphone jack?
 
thanks for the guidance.
 
Jan 20, 2013 at 3:14 PM Post #1,413 of 9,526
Sorry, I don’t know Voodoo; and I’m not an Android guru.
In fact, I’m an Android newbie, I switch from iPhones to Galaxy S3, my 1st Android phone.
 
As far as I understand, the current Voodoo-like custom solutions have improved software methods to process the digital audio stream and to handle the Wolfson conversion & amp chip of the Galaxy S3 in order to get an improved internal DAC and an improved internal amp.
It doesn’t impact the digital USB audio out.
 
 

 

 

 
Jan 20, 2013 at 5:42 PM Post #1,414 of 9,526
thanks for answering.  Since it is my phone, i am always a bit leery of changing something that could mess up the phone functionality.  I also thought that the T-Mobile US version did not have the Wolfson chip anyway.  I'd be more interested in a solution that involved a pairing of something like Neutron and the usb enabling of usbaudiorecorder to work together, as it looks like this may be something in-progress.
 
I do have other portable players, and the phone would just be 'one of the gang' anyway.  This is, however, a fun project And, as much as i would like to maximize performance and minimize 'size/weight', i know that that is not always possible, and I'll chose performance over compactness almost every time.
 
Jan 20, 2013 at 7:54 PM Post #1,415 of 9,526
Quote:
thanks for answering.  Since it is my phone, i am always a bit leery of changing something that could mess up the phone functionality.  I also thought that the T-Mobile US version did not have the Wolfson chip anyway.  I'd be more interested in a solution that involved a pairing of something like Neutron and the usb enabling of usbaudiorecorder to work together, as it looks like this may be something in-progress.

 
No need for USBAudioRecorder with the S3, USB audio works by default with whatever music player you want to use.
 
Jan 21, 2013 at 3:02 AM Post #1,416 of 9,526
Okay, about re-amplifying an amplified signal. Here is something that puzzles me.
 
I have an international T-Mobile Galaxy S3 and an iBasso D-Zero. USB audio out via the supplied OTG cable to the DAC works flawlessly. But changing the volume on the smartphone, changes the volume of the music I hear in my headphones.
 
How is that possible? The data stream from the smartphone to the DAC is supposed to be all digital, so how can it be amplified by the source?.
 
There is no way that the D-Zero is picking up an analog signal, sends that through the DAC and from thereon to its amp. USB is never analog, right?
 
Using the same DAC/AMP with a Macbook Pro or an iPad, the volume of the source component is automatically set to max and locked.
 
Any ideas? Thanks!
 
Jan 21, 2013 at 3:13 AM Post #1,417 of 9,526
Quote:
Okay, about re-amplifying an amplified signal. Here is something that puzzles me.
 
I have an international T-Mobile Galaxy S3 and an iBasso D-Zero. USB audio out via the supplied OTG cable to the DAC works flawlessly. But changing the volume on the smartphone, changes the volume of the music I hear in my headphones.
 
How is that possible? The data stream from the smartphone to the DAC is supposed to be all digital, so how can it be amplified by the source?.
 
There is no way that the D-Zero is picking up an analog signal, sends that through the DAC and from thereon to its amp. USB is never analog, right?
 
Using the same DAC/AMP with a Macbook Pro or an iPad, the volume of the source component is automatically set to max and locked.
 
Any ideas? Thanks!

 
It depends on how the DAC is set up, most DACs I use with my PC also allow PC-side volume and EQ control. Don't worry, your external DAC is doing all the heavy lifting.
 
Jan 21, 2013 at 3:40 AM Post #1,418 of 9,526
Thanks, NZtechfreak!
 
EQ control I understand. That is -I think- an alteration made to the outgoing signal made before it is passed to the DAC. EQ information is part and parcel of the data stream, so to say.
 
If I understand you correctly, volume level can be a component embedded in the digital signal offered to the DAC as well? And it depends on the specific DAC whether it does anything with that part of the data stream?
 
So it is both a function of the source component (the volume level offered to the DAC is either fixed or continuously variable), and a function of the DAC (is the DAC able to respond to changes made to the volume level offered by the source or does it ignore changes, or is completely blind to those changes)?
 
Jan 21, 2013 at 4:24 AM Post #1,419 of 9,526
Quote:
Okay, about re-amplifying an amplified signal. Here is something that puzzles me.
 
I have an international T-Mobile Galaxy S3 and an iBasso D-Zero. USB audio out via the supplied OTG cable to the DAC works flawlessly. But changing the volume on the smartphone, changes the volume of the music I hear in my headphones.
 
How is that possible? The data stream from the smartphone to the DAC is supposed to be all digital, so how can it be amplified by the source?.
 
There is no way that the D-Zero is picking up an analog signal, sends that through the DAC and from thereon to its amp. USB is never analog, right?
 
Using the same DAC/AMP with a Macbook Pro or an iPad, the volume of the source component is automatically set to max and locked.
 
Any ideas? Thanks!

 
Quote:
 
It depends on how the DAC is set up, most DACs I use with my PC also allow PC-side volume and EQ control. Don't worry, your external DAC is doing all the heavy lifting.

 
Quote:
Thanks, NZtechfreak!
 
EQ control I understand. That is -I think- an alteration made to the outgoing signal made before it is passed to the DAC. EQ information is part and parcel of the data stream, so to say.
 
If I understand you correctly, volume level can be a component embedded in the digital signal offered to the DAC as well? And it depends on the specific DAC whether it does anything with that part of the data stream?
 
So it is both a function of the source component (the volume level offered to the DAC is either fixed or continuously variable), and a function of the DAC (is the DAC able to respond to changes made to the volume level offered by the source or does it ignore changes, or is completely blind to those changes)?

 
 
Woah hold on both of you, changing the volume on your phone will cause a loss in SQ and lower the volume levels. Whats happening is digital volume control at 16bits, basically it sends less bits like 15~14 bits, and you lose those other bits in SQ.
 
The fix is to use 24bit output and the extra is just padded with 0's and then the 0's are truncated. so no loss in SQ. 
 
But this is not possible in android. SO you MUST keep the phone volume on max.
 
Jan 21, 2013 at 7:40 AM Post #1,420 of 9,526
Quote:
 
 
 
 
Woah hold on both of you, changing the volume on your phone will cause a loss in SQ and lower the volume levels. Whats happening is digital volume control at 16bits, basically it sends less bits like 15~14 bits, and you lose those other bits in SQ.
 
The fix is to use 24bit output and the extra is just padded with 0's and then the 0's are truncated. so no loss in SQ. 
 
But this is not possible in android. SO you MUST keep the phone volume on max.


Well that's strange. In my personal experience, if i boost the volume on my phone to max and adjust to a comfortable level on the dac, the lower bass will become distorted. If i lower the volume on the phone a bit and adjust on the dac the problem disappears, no distortion in sub-bass.

Any thoughts on this?
 
Ex:
 
Phone volume 10/10 + dac volume 3/10 = Bass distortion
Phone volume 7/10 + dac volume 6/10 = No distortion
 
Jan 21, 2013 at 10:25 AM Post #1,421 of 9,526
Quote:
Well that's strange. In my personal experience, if i boost the volume on my phone to max and adjust to a comfortable level on the dac, the lower bass will become distorted. If i lower the volume on the phone a bit and adjust on the dac the problem disappears, no distortion in sub-bass.

Any thoughts on this?
 
Ex:
 
Phone volume 10/10 + dac volume 3/10 = Bass distortion
Phone volume 7/10 + dac volume 6/10 = No distortion

****ty quality song? The loss of bits could be hiding it. 
 
Because trust me - I'm not wrong about the digital volume control
 
Jan 21, 2013 at 4:03 PM Post #1,422 of 9,526
Quote:
 
Woah hold on both of you, changing the volume on your phone will cause a loss in SQ and lower the volume levels. Whats happening is digital volume control at 16bits, basically it sends less bits like 15~14 bits, and you lose those other bits in SQ.
 
The fix is to use 24bit output and the extra is just padded with 0's and then the 0's are truncated. so no loss in SQ. 
 
But this is not possible in android. SO you MUST keep the phone volume on max.

 
Woah hold on yourself! :)  I wasn't saying that was a good idea, only that it isn't indicative that USB audio isn't operating correctly, which seemed to be the posters concern. Naturally it should be on full volume on the phone in most scenarios.
 
I have encountered bass distortion though as described by CynicalMushroom, but only with my Pico on my US S3 (when I had it) and with certain music like Massive Attack and using my LCD-2. Is certainly not a problem with my files, which are perfect FLAC rips. Will be interested to see whether that is also the case with the Pico and International S3/Note 2 when I get mine back from Justin with the compatibility fix for those handsets.
 
Jan 21, 2013 at 10:52 PM Post #1,423 of 9,526
Don't know how much it helps, but Neutron has a "Preamp Out" setting that supposedly sets the digital gain to zero, avoiding the truncation of bits. Having used the feature, I can tell you it doesn't lock the volume (or at least, I haven't figured out how to do it yet), so it isn't foolproof or anything. But this might address the loss-of-bits issue! :)
 
EDIT: Also wanted to mention that I've tried the Monoprice USB OTG adapter as well, and it works just fine (PID 9724, here). One advantage is that the micro USB side is a right-angle instead of straight connector, which I find more useful for our needs. Unfortunately it isn't a whole cable, so you'll still need your regular mini-USB cable too, but it's $1.43 and allows me to further my insatiably manly gearcrush on Monoprice stuff. 
 
Hope this helps somebody! 
 
Jan 21, 2013 at 11:03 PM Post #1,424 of 9,526
Quote:
Originally Posted by DanBa /img/forum/go_quote.gif
 
"D-Zero USB OTG hooked up to Galaxy S3. Works like a charm…
This is nice... I just received an iBasso D-Zero bought directly from the manufacturer. I had no idea that a short USB OTG cable is included in the box now.
The cable is marked iBasso Audio - Android 4.0 & Above USB OTG Cable.
 

Has anyone found a cable like this outside of China/HK?  I would think there should be a few takers of this vs. the archos cable listed on ebay and since most android phones are now micro plugged, there should be some market for it.  I tried to send iBasso a message via their web form and hope to hear something back from them soon.
 
Jan 21, 2013 at 11:27 PM Post #1,425 of 9,526
This looks like it might work, but it hasn't come in yet, so I can't vouch for its efficacy: 
 
http://www.ebay.com/itm/251211470827?ssPageName=STRK:MEWAX:IT&_trksid=p3984.m1423.l2649
 

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