This USB device is not detected on my Ubuntu 20.04 tower. I know the USB dongle, and headset is working, because they work on my laptop which has Pop!_OS 21.04.
On my tower I get this command response with the USB dongle plugged into one of its USB ports, and headset plugged into the dongle:
@ubuntu:~$ cat /proc/asound/cards
0 [SB ]: HDA-Intel - HDA ATI SB
HDA ATI SB at 0xfe300000 irq 16
1 [NVidia ]: HDA-Intel - HDA NVidia
HDA NVidia at 0xfe080000 irq 34
No USB device is indicated here. The same command on my laptop does show the presence of the HyperX Cloud II USB Headset.
I know the USB connection to my tower is good because the dongle's LED lights up.
The dongle does appear to be recognized as a USB device:
@ubuntu:~$ sudo lsusb
Bus 003 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub
Bus 007 Device 001: ID 1d6b:0001 Linux Foundation 1.1 root hub
Bus 006 Device 001: ID 1d6b:0001 Linux Foundation 1.1 root hub
Bus 002 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub
Bus 005 Device 011: ID 0951:16a4 Kingston Technology HyperX Virtual Surround Sound
Bus 005 Device 001: ID 1d6b:0001 Linux Foundation 1.1 root hub
Bus 001 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub
Bus 004 Device 002: ID 04d9:1702 Holtek Semiconductor, Inc. Keyboard LKS02
Bus 004 Device 001: ID 1d6b:0001 Linux Foundation 1.1 root hub
Bus 009 Device 001: ID 1d6b:0003 Linux Foundation 3.0 root hub
Bus 008 Device 003: ID 1e7d:2e7c ROCCAT
Bus 008 Device 002: ID 2109:3431 VIA Labs, Inc. Hub
Bus 008 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub
How is this failure to detect it on my tower fixed?