Noob question

Discussion in 'MacBook Pro' started by Bri in Mtl, Dec 7, 2014.

  1. Bri in Mtl macrumors member

    May 29, 2013
    Why don't I see some devices like, for example, my FiiO amp while it's charging via USB, in Finder's device listing?
    Thanks in advance for any and all replies.
  2. jonbravo77 macrumors 6502a


    Feb 20, 2008
    Phoenix, AZ
    I assume that if the device does not have a formatting that the Mac can recognize than it won't mount it and therefore you won't see it in the list. If it's a drive that is formatted NTFS (windows) than you can use Tuxera on the Mac which will allow the Mac to not only recognize it but also write/read from the device.
  3. snaky69 macrumors 603

    Mar 14, 2008
    Your headphone amp does not have any on board memory, it can't act as a storage device, so there really is no use in seeing it in finder.
  4. sebseb macrumors 6502


    May 24, 2014
    Your computer/laptop USB ports can supply 500mA 5V output. Many products use that to power themselves.

    A USB cable has 4 wires. (+5V), GND( Ground or -), DATA+,DATA-

    if you connect a device that only uses 5V and GND, it will not appear in any device list. However when you connect a thumb drive, since it uses DATA+ and DATA- as well, it appears in devices that are connected and if the OS has drivers for it, it will recognize it as a USB drive.

    In the case of the FiiO, it doesn't use the USB port as audio in but just to power itself and to eliminate the need of a charger or power brick. Therefore only using 5V and GND and none of the DATA wires.

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