USB sound problems

Hi,
I wonder if someone could help with an USB sound problem. I have a sudden loss of sound due to my speakers being switched off. My system consists of:-

USB KEF egg speakers
Windows 7 ultimate x64bit
Kodi 17.3

The problem I have is that when I’m watching a film the KEF speakers are suddenly switched off, there doesn’t appear to be an event that causes it. It just switches to another sound source, when I turn the speakers back on they come back into play. This can happen every 10 seconds or so. This didn’t happen under Jarvis and this is a fresh install from scratch of Krypton as I deleted the user directory and all settings before installing Krypton. Is this a common settings problem and if so what do I need to do to resolve it. I appreciate that I may not have given you enough information at this stage to resolve this problem and I apologise if this is the case. I’m looking for pointers of where to go before drilling down further and giving out more pertinent and appropriate information.

I freshly installed Krypton on a windows 10 pro x64 laptop with exactly the same problem, so I think it’s the interplay between Krypton and USB speakers.

Thanks for your help.