i can't find the use of conecting a USB Headset to the Mpx player because the USB Headset main body will be three or four times bigger than the player, second, i don't belive that will be possible, let start: there is 2 types of USB Devices:
- Client (Slave or active)
the server type is usually a PC
the Client are the peripheral (printers, mouses, keyboards, memory sticks, headsets, mpx players..... i made my point
the USB protocol relies in a Server-Client comunication then you can't connect a Client to another Client directlty, you will need a device working as server for both devices.
in the hypothetical case you connect the MPx Player to USB Headset you will need the next:
- a hypothetical device where you connect the player, that device will read (and process) the files in the player, because the player is only a USB Mass Storage Device in the USB (the player has the read and process files in firwmare).
- the same hypothetical device must receive the USB Headset and send the procesed stream.
another config wil be:
another hypothetical device, in a side you connect the hearphones output of Player to the device, the device will convert the analog input to a digital output what will be send to USB Head set.
in eigther case you end with a device twice bigger than the mpx player, a high battery drain (the MPx player must feed the player, the device and the headset) and possible low quality sound (if you make by hand the device)
then is your choice, i recomend:
have a nice day,
pd sorry for my english