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Good news about Android phone supports digital audio output - Page 14

post #196 of 253
Given someone is able to get E17 working with Archos G9 even with the buggy descriptor, I don't think it isn't an unsolvable problem without FiiO trying to fix the descriptor. It will be good if FiiO did so anyway, but it is part of the problem, not all of the problem.
post #197 of 253
Quote:
Originally Posted by ClieOS View Post

Given someone is able to get E17 working with Archos G9 even with the buggy descriptor, I don't think it isn't an unsolvable problem without FiiO trying to fix the descriptor. It will be good if FiiO did so anyway, but it is part of the problem, not all of the problem.

I already stated that....

post #198 of 253
Quote:
Originally Posted by ClieOS View Post

The USB chip in E17 is the same one used in ODAC, the Tenor TE7022. I don't really think there is anything wrong with that chip, but it isn't quite as easy to implement as the TI PCM27xx chip in E7. You'll need to understand E17 use a totally different circuit designed than the E7. The Tenor chip feeds the USB signal to a Wolfson SPDIF Transcoder, then the transcoder feed it to the DAC chip. In comparison, E7's TI chip feed directly to the Wolfson DAC. The extra chip and circuit on E17 is what make it possible to take SPDIF signal as well as USB. But those come with a price in power draw. It is common practice in the industry for DAC section to draw power directly from the USB port, so even with recharging disable, it only stops the battery from charging, not the DAC section from not drawing power from the USB port. If you consider that, you will know why your smartphone can support E7 but not the E17, because E17 is much more power hungry than E7 will ever be.


Finally something I could understand without all the USB jargon.  Thank you!

post #199 of 253

is it really that hard to understand? its been explained numerous times. some dacs need more than 100mA, portable devices in general do not want to supply more than 100mA over a USB connection they are hosting, as it strains the power supply and shortens battery life. some dacs will work as they are working on 100mA or around that amount, some use more; thus need to supply their own power and be able to tell the android device/host they can do that.

 

pretty sure ClieOS was just trying to keep it simple, but the tenor chip does not transcode USB over to WM8804/5, it sends I2S, thats the whole point of the tenor chip, convert USB to i2s
 


Edited by qusp - 8/1/12 at 11:30pm
post #200 of 253
Yep, that's what I mean. I am not 100% sure whether the Tenor chip in E17 is sending I2S or SPDIF-TX to the transcoder actually, but I think it is likely the later.
post #201 of 253

thought you might be.

 

spdif for easier MUX? cant think of another reason to add 2 extra conversions. then again most companies releasing portable dacs dont seem to care too much about jitter, even the so called high end.

post #202 of 253
Quote:
Originally Posted by qusp View Post

is it really that hard to understand? its been explained numerous times. some dacs need more than 100mA, portable devices in general do not want to supply more than 100mA over a USB connection they are hosting, as it strains the power supply and shortens battery life. some dacs will work as they are working on 100mA or around that amount, some use more; thus need to supply their own power and be able to tell the android device/host they can do that.

 

pretty sure ClieOS was just trying to keep it simple, but the tenor chip does not transcode USB over to WM8804/5, it sends I2S, thats the whole point of the tenor chip, convert USB to i2s
 


No, it's not that difficult, but then again it wasn't stated that simply before and even if it were, that was before some of the things which ClieOS said were made clear, like that the battery doesn't power the DAC (which makes the not charging through USB function kind of useless).  And you further cleared it up even further with the underlined statement. 

 

It still sounds like something which can be modified to work although might be very technically involved to do. 


Edited by Typhoon859 - 8/2/12 at 1:14am
post #203 of 253
Quote:
Originally Posted by qusp View Post

thought you might be.

spdif for easier MUX? cant think of another reason to add 2 extra conversions. then again most companies releasing portable dacs dont seem to care too much about jitter, even the so called high end.

Probably because WM8740 only takes one set of I2S input, but WM8805 can take up to 8 channels of SPDIF input. So the whole implementation becomes simpler if WM8805 is used to control which input (optical, coax or SPDIF from Tenor) feed into the DAC instead of a different mechanism to control whether WM8805's or TE7022's I2S is used.
post #204 of 253

yeah like I said, MUX. a MUX in these terms is a switch/hub for digital inputs. i2s switching is a bit more involved than spdif. but with only 2 inputs its hardly a big deal. none of the receivers or dacs have multiple I2S inputs, not even 9018, the solution lies beforehand, particularly when you have the advantage of the WM880X doing async.

 

spdif has inherently higher jitter, but i2s in order to do better than 880x (which is quite a good receiver if done well) needs careful routing, good termination/grounding and impedance controlled PCB layout. the problem of the MUX is not hard to solve, the rest is perhaps beyond the scope of a device at this budget, or the skillset of the designers. thats OK, its a consumer device, but its all too common in these portable devices to take the path of least resistance.

 

 

Typhoon859: no its not straight forward, if it is set with pullup resistors it could perhaps be done, but if its a firmware setting then theres nothing the user can do about it


Edited by qusp - 8/2/12 at 3:36am
post #205 of 253
Quote:
Originally Posted by qusp View Post

Typhoon859: no its not straight forward, if it is set with pullup resistors it could perhaps be done, but if its a firmware setting then theres nothing the user can do about it

Yeah, that's what I meant by possibly very technically involved to do, and by this I mean for the average person and what would be worth it for them, not necessarily me.

post #206 of 253
Thanks for the info. It is good to learn new stuff.
post #207 of 253

A slightly modded Nexus 7 interworks with a standard USB DAC FiiO E10 (that doesn't work with stock Samsung Galaxy S III for the moment):

http://www.head-fi.org/t/595071/android-phones-and-usb-dacs-how-to-increase-the-issues-priority-with-google/225#post_8599585

post #208 of 253

Sorry but, to be more clear, I have to sell my E17 cause it cannot ever work with my HTC Sensation?
 

post #209 of 253
Quote:
Originally Posted by _mouse_ View Post

Sorry but, to be more clear, I have to sell my E17 cause it cannot ever work with my HTC Sensation?

 

Sold mine because the DAC section was a bit too warm and my current portable solution (SGS3-> Pico DAC/Amp) is much more neutral, portable, and detailed when compared to my old setup (Archos 101 G9-> E17-> TTVJ Slim)...

Kojaku
post #210 of 253

R: Good news about Android phone supports digital audio output

Quote:
Originally Posted by Kojaku View Post

Quote:
Originally Posted by _mouse_ View Post

Sorry but, to be more clear, I have to sell my E17 cause it cannot ever work with my HTC Sensation?

 

Sold mine because the DAC section was a bit too warm and my current portable solution (SGS3-> Pico DAC/Amp) is much more neutral, portable, and detailed when compared to my old setup (Archos 101 G9-> E17-> TTVJ Slim)...

Kojaku
400$ for a portable amp?... not for me
Inviato dal mio HTC Sensation con Tapatalk 2
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