USB OTG

[ToeTag]

Users report that the DACport LX is not properly recognized by USB OTG as an audio output device. For recent phones like the Samsung Galaxy S III or Samsung Galaxy Note II. This lets cell phones act as a USB host, and send music in untouched digital form out a USB cable and into a DAC.

It should be easy to fix, just by changing some data in your ROM. Here is the best technical explanation I could find. http://www.head-fi.org/t/595071/android ... st_8807747 (talks about a different DAC but the symptoms and their cure are probably the same).

If you read the rest of that thread, it explains what USB OTG is, why its important, its history with Android, lists which DACs work, what cable is needed, the difference between user space support and proper kernel support, etc.

EDIT: in fairness, its hard to say definitively if it’s a CEntrance DACport issue or it’s a Samsung issue. I would ask other users of the few popular devices that have USB OTG Audio (as reported in the head-fi thread) to test them with the DACport. In some sense though it is hard to blame the phone manufacturers for following the spec to the letter.

[david]

Hey ToeTag,

We are looking in to OTG compatibility. There are a lot of variables that complicate things, including power requirements and max sample rates. Evidence that Android is still not fully mature, yet. But I think it will improve significantly in 2013.

Please keep us posted, either here or on head-fi. Any feedback is appreciated.

David

[ToeTag]

The DACs can blame Android, and Android can blame the DACs but that won't get us anywhere. The thread has a growing list of combinations that work http://www.head-fi.org/t/595071/android ... st_9038046 (whether by luck or by skill). I would say if you just test on the Samsung Galaxy Note 2 (5 million sold) or the S III (30 million sold) those are and will remain the dominant sources for USB OTG.

[david]

as of 1/17, see today's blog post

http://centrance.com/products/new/blog/

[ToeTag]

Interesting, and glad you are getting involved with the issue. All I can add is that there are dozens of working DAC-USBOTG-Android combinations that work. http://www.head-fi.org/t/595071/android ... st_9064874

Maybe none of those are 192K. Maybe all are 48K. But I thought some were at least 96K. So even if Android is doing wrong to your forthcoming HiFi-M8, can the DACport get along with Android, as other DACs seem to?

[ToeTag]

Well guys, I like the DACport LX. I mean I want to like it. It sounds great. But it has 2 fatal flaws if you want to actually use it with your cell phone. Which I thought was the whole point of a portable DAC. First it runs very hot. And that heat means its draining your cell phone battery in a hurry. Second, while many DACs support USB OTG, yours does not. Do you have any care to fix this? I brought it to your attention nearly 5 months ago.

[david]

Hey ToeTag,

Thanks for the feedback.

DACport was primarily designed to be used with a laptop. DACport's ability to drive many hard-to-drive headphones requires power, which we wouldn't want to rob from a relatively tiny phone battery. Hence, the reason why our soon-to-be-released HiFi-M8 will have its own internal battery. While DACport was primarily designed for laptop use, it can also be used with an external battery pack with items like iPad.

David

[ToeTag]

David, okay, but this is the LX forum. LX is just a DAC, and does not drive any headphones. I remain disappointed that a mere DAC has to drain so much power. And that you can't repair its ID strings so USB OTG will talk to it.

On top of that, you say, well we designed it for laptops. OK let's look at Apple. About 10% of their revenue (probably less in terms of units) is laptops or desktops. The rest is iPhone, iPod, and iPad. By "designed for laptops" you aim at the 10% and not the 90%.