[Luxman1050]

Wahey guys am I chuffed or what thanks a million for your input.
You won't believe this but as said I put 180r in series with R37 as suggested by Lawrence and every heater is bang on not a volt out.
Rectifier 50v
UBL21 55v
UCH21 pair 20v.

Taken 4 measurements over an hour.

I have changed around 5 resistors as they where starting to deteriorate and where well out of spec.

Brilliant guys I'm over the moon I can now refit the unit back in its cabinet tidy up wiring etc and done it does sound nice and clean now.

Superrrrrrrrrrrr

All best Chris