I don't get this about Win10 support. Are you saying that they won't work on Win10 either?
All the USB audio 1 devices I have do work under Win10. But I have not tested headphones as I don't have a USB headphone.
Windows 10 recently dropped class1 (1998) support on Win10 devices, none of my early USB DAC's work on Win10 since late fall last year, some others are 1.1 compliant and seem to work, some are supposedly 1.1 but do not work or work only partially (Phillips CODEC's only work if volume is 100%), some are class one compliant and are no longer seen as class compliant devices but have drivers supplied on the windows distribution (CMedia et al) and work, but others like Roland/EDIROL/Boss units no longer work in class compliant mode but work in "driver mode", if you manage to install older drivers that is. Others like Focusrite Saffire 6 USB 1.1 only work with Windows using the ASIO drivers which is a world of pain for those that do not know what ASIO is and how to route it to the system.
Note that there were 2 versions of the Saffire 6, a USB1.1 and USB 2 version, the latter still works, but both are only about a decade old, Ploytec only started shipping their asynchronous USB 2 development package in 2011, it was all USB 1 up until then. CMedia also has the bad habit of supplying different chips with a very similar or sometimes even the same name, some early CMedia USB audio chips no longer work with either the Win class drivers or CMedia drivers, even though the CMedia drivers supposedly work with that part number, turns out that they recycled the part number for a later and different USB CODEC.
I am not necessarily unhappy about this development, I have been buying weird old USB audio products for peanuts off eBay in the last couple of months. USB powered digital amplifiers and old hi-fi DAC's with programmable DAC chips and isolation transformers on the audio output, so on, so forth.