Hi Guys,
Well after five hours on Sunday changing to Shottkey diodes and a Pi filter I was getting 9 .5 volts on the heaters without the ECF80's in. I tried three meters, at least I know the cheap meter is fit for the bin. I replaced the original rectifier and with cap in circuit it was still over 9 volts
I also replaced some of the thin wire with some Neotech with more to go.
The bad news it the hum is still there and is intermittent from quite low through the speakers to very load, it can just start getting loud and then goes quiet. There is no hum from the transformers just through the speaker which are approx 92db efficient.
The good news is the more I play the more I learn.