Usb config / rate

kernel: usb 1-7: current rate 16000 is different from the runtime rate 48000
kernel: show_signal: 66 callbacks suppressed
kernel: usb 2-4: new SuperSpeed USB device number 2 using xhci_hcd
kernel: usb 2-4: New USB device found, idVendor=0930, idProduct=6545, bcdDevice= 1.10

How to control and handle the usb rate via NixOS?

I don’t think that it’s something that you can control directly (on any linux). After a quick search it seems that this kind of errors can occur if you are not using a proper USB port. Maybe check if you are using a USB 3.x port (actually I think that some devices even need usb 3.1 instead of 3.0), they are typically blue. Also make sure to plug your device quickly enough, if you plug it too slowly it may be detected as usb 2 (due to the fact that usb 3 has additional wires at the end of the connector). Some people also reported that some ports were working while other were not… so surely check with all your ports. Other people reported that upgrading the firmware of the usb device helped, not sure if it can be your case. Finally the version of the kernel can maybe make a difference… so maybe try with a more recent/stable kernel version.