After experiencing this issue with my gearbox ux1 failing today after a reinstallation of win 10, i got it working.
I had tried everything. Every single driver, old and newer. Uninstall /reinstall drivers everything, reading countless similar issues with users online. I was banging my head against my guitar. Countless blue screens. Line monkey not working. Literally giving up but then found the solution! My device was given to me by a mate back in 2005ish so i am unable to register it as its quite old now despite not being registered previously. I have the orig install disc somewhere but cannot find it.
It is to do with your audio settings and default devices. I use via hd audio for my output this needs to be set as; output tab or play tab to default and on the recording tab to gearbox toneport ux1 (,or the device you are using) has to be set as default communication device. You have to also tick a box for; listen to this device and you also need to tick the box on twin/dual audio output within system audii or the pc will not play audio at the same time as playing the output from gearbox or whichever hardware device you are using.
Hopefully if anyone has this issue of their device no longer working in win 10 this will save them from throwing their device in the bin and getting something else. Why don't Microsoft make things clearer and easier for users to figure things out? Then again that is not what Microsoft do right. Cant stand them myself.
Hope this helps someone out there.