After a lot of faffing and help from my son, I got the firmware update installed. My SBT found the new USB app and I was able to listen on USB for the first time.
Of course, this was a bad decision. I shouldn't have tried two things at the same time. At the moment my system is lacking top end sparkle but the bass seems a little better. At the weekend I will revert to coaxial (I have a very good cable) and see if the cheapish USB cable is the problem.
Jerry
Hifi: IPL transmission line floorstanding speakers, Squeezebox Touch, Denafrips Ares 11 DAC, DCB1 Pre-amplifier, Croft Series 7 power amp.
Custom Hifi cables HA10SE headphone amplifier and Hifiman HE-400 headphones.
AV system: LG 55B7, Denon AVR -x2300w receiver, Quad 12L (front) 11c Centre and 11L rear . Velodyne DD15 subwoofer.