Developers of some USB DAC and of some Android devices don't have the same understanding of the USB specification: an example
"I was puzzled because another contributor to this thread (SetiroN) had basically the same setup that I did -- a Nexus 4, an AOSP-based Jellybean firmware (in his case, CM10.1), a ziddey OTG kernel, and this patch -- and it worked perfectly for him. I went so far as to wipe my phone, start from scratch with a CM10.1 install myself, apply the exact same ziddey kernel that he reported was working for him, plus this patch, and STILL I would have the same issue.
The only thing different was the DAC he was using. So I sourced for myself one of the same DACs (ELE DAC EL-D01, from Chinese-based eBay seller, ~$15USD), and whaddya know: worked perfectly.
It turns out that not all USB Class 1 Audio devices are created equally. And, as far as I have been able to figure out, the problem isn't that one device or another doesn't follow the spec, but rather that the spec allows for some variability. In my case, I eventually discovered that the DACport was reporting to the host that it supported sampling rates of 44.1/48/88.2/96kHz, but ONLY at a depth of 24-bits. In contrast, the EL-D01 reported that it would only accept 44.1/48kHz at 16-bits natively. (You can interrogate the DAC by looking at /proc/asound/card1/stream0) The DACport actually does support playback of 16-bit samples, but it expects the host to pad each sample that is narrower than 24-bits with zeroes. Apparently this is not all that unusual, and other OSes with native USB Class 1 Audio support know to do this (Windows, OS X, etc.).
I eventually discovered that CEntrance had actually written an alternative version of the DACport firmware a couple of years back that eliminates 24-bit playback support and causes the DAC to report only 44.1kHz and 48kHz rates at 16-bits; they apparently did this after it was discovered that the iPad Camera Connection Kit exposed a full-blown USB host controller in the iPad and that iOS apparently has USB audio support built-in, and some of their customers wanted to use DACport with an iPad. Apparently iOS at the time didn't support 24-bit DACs, similar to Android today. CEntrance would provide customers with a copy of this alternate firmware upon request, and after flashing it to your DAC, it would indeed work with an iPad (at the expense of support for 88.2/96kHz sampling and 24-bit-wide samples in the DAC). CEntrance eventually stopped publicly distributing this firmware build because iOS eventually started supporting 24-bit DACs, and so the standard firmware could be used with iPads out-of-the-box without difficulty.
I managed to get a copy of this old "iPad" firmware for the DACport, flashed it to my DACport LX, and voila, as they say: it, too, now works perfectly fine (with hot plug/unplug) with Android 4.2.2 on my Nexus 4 using the jacknorris patch."