[thejazzageuk]

Thanks Techman, PJL and Herald1360. Lots of good advice. In the end I installed the capacitors without the resistors or fuse, planning to add these later (if I get round to it).

So.. with the new caps in place and lamp limiter on, much better, still hum about one third level of music. Then I took out the lamp limiter, hum much lower frequency and much reduced volume, and reduces with volume increase. I then operated the middle Knob on the amp (radio/Gram/Brilliance), and hey presto- the hum has almost completely disappeared. Sounds fabulous! Any advice on how long I should let it run/ checks to do?

When the cleaning solution arrives, I will clean the valve contacts and socket contacts and perform the checks suggested by Techman in post No. 171.