Has anyone tested the USB sound card Behringer UM2 on patchbox?
It is a really affordable solution to have a decent sound on raspberry pi.
The sound card works in a normal distribution of Raspbian, but i dont know if the driver is in Realtime kernel build.
The UM2 uses the pcm2902 chip.
Thanks
The OS should use the standard USB audio driver for USB audio interfaces. See here for a table with recommended buffer settings based on audio card type. The hat-type audio cards for Raspberry Pi can have lower buffers because they communicate via the dedicated I²S interface on the GPIO pins.
I have not used patchbox OS but I had a UM2 and tried it with MODEP image on my Pi. It does not handle low latencies well on Pi, I think it needs buffer of at least 512, maybe even 1024 samples to work on a Pi. If youre running on core i7 then you may get better results 
i had um2, still have umc22 and umc202 and also had umc404. Guess what, the more it costs, the lower min latency it can handle (tested on win PC though). If I remember correctly, only umc202 and 404 handled 128 sample mode w/o issues.