DAC, USB sound cards and Note 4

Yesterday, just out of curiosity, tried to plug in my PC headset to the Note 4. The headset is a Creative Tactic 3D sigma, an average to low-end headset with an equally low-end external USB card. So, I plugged a USB OTG adapter on the phone, then the external USB to the adapter and then the headphones. It worked! The sound was far worse than the phone's, low volume and very "empty", but the thing is that itw worked.
So, it got me thinking what would happen, if I had a better external USB card. Would this be a viable option, compared to an external DAC? Has anybody else tried something like that?

Questions about swapping SD cards

So I have a rooted Xperia Play with a 32 GB SD card. I'm wanting to upgrade to a 64 GB SD card. I only use the Xperia for emulators. So my question is, could I transfer save states, root, current android version, and everything else over to the new SD card without any issues? No bricking? (I only have a general knowledge of all this). Would really appreciate some assistance!

No sim cards detected after OOS 3.2.0

Hi,

I was on OOS 3.1.3 (rooted).

I installed the latest 3.2.0 by:

wiping cache/dalvik
installing full .zip 3.20 via TWRP (downloaded via the amazon aws link)
wiping cache/dalvik
Flashing SuperSU
wiping cache/dalvik
Reboot

Everything seems fine but my phone says no sim card installed. The baseband in About is unknown. And I can't open the screen which shows the IMEI etc on my phone.

Is my EFS wiped out? I made a backup so should be ok. But I am confused as to how to proceed on this?

I have tried to fix this by:

1. Trying to restore the EFS backup using the "fastboot flash modemst1 modemst1.bin" commands (same for modemst2.bin) - I had made a backup of EFS earlier. It doesn't seem to do anything and when I reboot, there is still no baseband.
2. Trying to flash the full ROM zip again - without success

Before I proceed to do anything further, I am hoping someone more intelligent than me can shed some light as to what may have gone wrong and what I can do about it, instead of me managing to make things worse.

Any help would be much appreciated!

How to set up data usage warning on both sim cards

Hi!

My Op3 is only allowing me to set a data limit warning for one of the sim cards..

For Sim 2, it show the chart and "Set cellular data limit" option and, on the chart, the two line bars to set up the warning and maximum limit.

For Sim 1, it only show the chart, but no "Set cellular data limit" option and no line bars to set the up the warning and maximum limit.

Weirdly, for SIM 1 it show the date interval, which it doesn't for Sim 2..

Also.. where can I change the date interval?? It is assuming a wrong interval...

Thanks!