The Lab PSU is finished with everything running and I can work with music playing in the background. I can now get on with the pre/power amp unit. It has been over 10 months since I was last able to work on it so I am having to spend some time reacquainting myself and working out where I left off. I can see most of the work has already been done, the only thing left is to work out the placement of the headphone circuitry. That really won’t take long and I can then start building the amp!