Guys,
What is the type of the Micro USB receptacle of your USB DAC-compatible Android device, type Micro-AB or type Micro-B?
Coop's Galaxy S3 and my Galaxy S3 have a Micro-B receptacle:
Coop, thanks!
USB is a master-slave communication bus.
USB communication can only take place
between a master device and a slave device,
i.e. between a USB host and a USB peripheral,
i.e. between a A-device and a B-device.
A non-USB OTG device always acts as an A-device or always acts as a B-device.
An A-device has a USB host controller hardware component.
A B-device has a USB peripheral device controller hardware component.
A USB OTG device, like a Galaxy S3, is a dual-role USB device, sometimes an A-device, sometimes a B-device.
A USB OTG device has a USB host controller hardware component, a USB peripheral device controller hardware component, and also USB OTG hardware/software components which measure the (Pin 4) ID resistance and configure the USB OTG device to USB host mode or to USB peripheral mode depending on the value of the ID resistance.
The USB connector mounted on a USB host or on a USB peripheral is called "receptacle", and the USB connector attached to the cable is called "plug".
A non-USB OTG device always acting as a USB host or A-device has an A-receptacle. Only a Type-A plug can be mechanically inserted into a Type-A receptacle.
A non-USB OTG device always acting as a USB peripheral or B-device has a B-receptacle. Only a Micro-B plug can be mechanically inserted into a Micro-B receptacle.
A USB OTG device, sometimes acting as a USB host or A-device, sometimes acting as a USB peripheral or B-device, has a AB-receptacle. A Micro-A plug or a Micro-B plug can be mechanically inserted into a Micro-AB receptacle.
"The standard connectors were deliberately intended to enforce the directed topology of a USB network: type A connectors on host devices that supply power and type B connectors on target devices that receive power. This prevents users from accidentally connecting two USB power supplies to each other, which could lead to dangerously high currents, circuit failures, or even fire."
http://en.wikipedia.org/wiki/Universal_Serial_Bus
A non-USB OTG Android device always acting as a B-device can’t work with a standard USB DAC always acting as a B-device.
A USB OTG Android device, like the Galaxy S3, when acting as a A-device, can work with a standard USB DAC always acting as a B-device.
And a USB OTG Android device, like the Galaxy S3, should have a Micro-AB receptacle, and not a Micro-B receptacle.
In order to allow a Galaxy S3 to work with a USB peripheral, cable manufacturers have to provide cables with a functional Micro-A plug (i.e. pin 4 ID connected to pin 5 GND) having the physical appearance of a Micro-B plug!
It is not a critical issue, because such a plug can be inserted into a USB OTG Android device with a standard Micro-AB receptacle.