MixerFace R4 Mobile Recording Interface

I love this thing! I rarely need audio inputs as I'm primarily an in-the-box musician these day. So this review is just about using it as an ASIO/Core Audio interface for output purposes only. I use Steinberg Cubase and Ableton Live. The MixerFace R4 provides solid 96kHz 24-bit performance at a 128 buffer setting with an input and output latency of around 4.4ms. Unlike most of the other audio interfaces I've used (MOTU, Focusrite, and Behringer to name a few) I did not need a preamp for my Beyerdynamic DT-1990 Pro headphones, which is really cool.The unit can be powered by USB (via a dedicated USB port) or the unit's internal battery. Yes, that's correct; it has an internal lithium battery that can keep it going for at least 6 hours. (that's the longest I've used it on battery so far) If you're using it at home and want to keep it powered via an outlet you'll need to buy a separate USB charger and cable for the charging USB port and keep the data USB port plugged into your computer with another USB cable. Initially, I thought it was strange that the data USB port doesn't supply power to the unit or charge the unit's internal battery. But if it did that, then it would never use the battery. Maybe a "charge mode" switch could have been implemented, but in any case, it has two USB ports -- one for data and one for connecting to a charging source.No drivers were needed to get it working on a Mac. It's class-compliant and Core Audio provides the low latency input/output.On a Mac, you lose your OS-level volume slider functionality. Which is common among audio interfaces, but still really annoying. (it can obviously be overcome by adjusting the physical volume knob on the MixerFace) I'm not sure why some audio interfaces have this "problem", and others do not.It's tiny. It's about the size of an iPhone SE in length and width and about as thick as two iPhone SEs. But it's also built like a tank. It feels super solid with an all-metal enclosure. All of the switches are DIP switches, so none of your settings will get changed while in transport. It's kind of funny (but also thoughtful) that the unit comes with a paperclip that you can use to change the DIP switch settings.I'm considering using it as my home audio interface too. I love its size not just for portability but for general compactness as well.I highly recommend it!

It was advertised specially for iPhone, iPad, iPod but you have to get extra connector for the job.