OK.  Next step is to dig in to what these mean:

[   46.508331] ALSA urb.c:480: frame 0 active: -75
[   46.560332] ALSA urb.c:480: frame 0 active: -75
[   98.971734] ALSA urb.c:146: timeout: still 7 active urbs..
[  104.970917] ALSA urb.c:146: timeout: still 2 active urbs..
[  121.260876] ALSA pcm.c:223: 4:2:1: usb_set_interface failed

Others might know what these mean.

Me?  I don't.  I'd have to inspect the kernel source code.  urb.c and
pcm.c are file names in the kernel sources (possibly in the sound/
folder).  The number after the colon (:) is a line number.  So, if you
go to urb.c line 480, you see something like printk(KERN_ERR "frame:
%d active: %d", frame, active);  The code around might give a clue to
what actually failed.

-gabriel