USB Audio on iPad

Hardware, iOS, iPad

Share

As I mentioned in a previous post, the iPad does not support audio line level input through its 30-pin dock connector. This would seem to be a major limitation of the iPad, as far as audio-band test and measurement is concerned, if it weren’t for the fact that the iPad can function as a USB host for USB audio input/output devices. Unfortunately, however, connecting a USB audio device is not as straightforward as it might seem. The goal, here, is to enumerate some of the current issues with USB audio on the iPad.

Add a USB port to your iPad with the Camera Connection Kit

USB audio support on the iPad — issues to be aware of:

  • USB devices currently must be connected to the iPad via the USB port of the iPad Camera Connection Kit. It’s the USB-dock adapter in the camera connection kit that switches the iPad into USB host mode.
  • The iPad can only provide bus power to low-power USB devices (those which draw 100 mA, or less, of current). Devices that require more power can still be used with the iPad, but they will either need to be self-powered (typically via a battery or AC adapter), or they will need to be connected via a powered USB hub.
  • The iPad supports full-speed, 16-bit, USB audio class compliant audio devices. High speed and 24-bit devices are not supported. Devices which to not conform to the USB audio class are also not supported. If a device supports both 24-bit and 16-bit operation, it should be switched to 16-bit mode before it is connected to the iPad.
  • Only sample rates up to 48 kHz are supported.
  • When a USB audio device is used for input, neither the iPad’s headphone jack nor its built-in speaker can be used for output. Both input and output are routed through the USB port, by the OS.
  • Asynchronous USB audio devices experience periodic data loss when used with the iPad. (Hopefully, Apple will move to properly support asynchronous USB audio devices, soon, since this essentially renders useless a significant number of otherwise capable devices. I’ll indicate which devices I have found that fall into this category in a future post.)
, , , ,

6 comments

  • Jim Amsden
    November 30, 2010 at 9:00 pm

    IPad running 4.2.1 seems a bit more conservative about power. The blue yeti for example no longer works without using a powered USB hub. I also noticed that you can’t use an Y-adapter to power the mic either. The mic gets power, but still reports the same power requirements preventing it from working.

    The other devices listed as working will need to be retested.

  • Gray
    March 10, 2012 at 4:18 am

    Hi do you have any recommendations for supported hardware?

    Thanks

  • GaryReg
    September 30, 2012 at 2:06 pm

    I wish to connect the 3rd gen iPad to my Outlaw RR2150 receiver’s USB port. This works great from my MacBook Air so with the camera kit you mention will it also work with the iPad?

    Thanks,
    GaryReg

  • Angie
    October 26, 2012 at 11:34 am

    Hi, could you please email me if you can answer any of my questions? I’m debating on whether or not to buy the ipad. I want something cheap just to use for internet purposes and I don’t want to have to buy a second computer. However I do need the usb compatability. Meaning if I have a file on a usb stick and I need to email it to someone will this usb connector be able to do that for me? Will it transfer the file, or will it only transfer picture files?

  • Zine
    January 1, 2014 at 1:43 pm

    I am wondering if the USB audio also works on a real USB stick, meaning can you use a real USB stick to the USB port or is it only for pics?
    I have a iPad but I want to use my iPad for my printer but my printer has a USB Stick you have to pluck in device so would it work?