the t.bone MicPlug USB

I bought this to enable me to plug an XLR condenser Microphone into my Macbook. The device functioned 'out of the box' (e.g. no driver installation) which was great. To get vaguely decent volume levels required the on-device gain and OS-X gain to be set to 'Max'.

During an audio recording, significant noise (hum) is heard in the sound signal, consistent with a switch-mode PSU in the device (continues when mic is unplugged, and with 48V switched on / off).

USB interface on the back is fragile, and cable is not of high quality, the knob on the device is small and difficult to adjust, and doesn't travel fully around.

I have returned for a Focusrite Solo (£80) which is a desktop box, and would suggest you consider the Shure X2u if you really need the 'inline' form factor (but haven't tried either).

It works just as intended. Audio from my mic was then read loud and clear on the mobile laptop I have.

Well, not all that clear, actually. This interface comes with a fair amount of background noise. It also isn't the most sturdy piece of equipment I've seen; the USB port on the back seems fragile enough to disconnect at a moment's notice after just a few months of use, for example. The buttons on it aren't all that clear at first, but soon didn't matter because they didn't do anything anymore anyway. Also the LED light on it died, which is unfortunate since that's the only indicator whether it's plugged in or not.

All in all, it's a decent interface for its price, but it's not decent enough to do any sort of recording with it. If you're a beginner trying to save as many pennies as you can, that's okay but don't be too cheap on this part; the extra $50 that you'll spend on a decent interface will go a long way. If you're just looking for an interface that links your equipment to a computer, then only then is this for you.