[MeerKat]

Many thanks for the article John, it is quite readable and I'll study it carefully and see which mods I will do.

Thanks for the heads up on the caps Ted, just had a close look at mine, see photo, they definitely need changing!, now where to get them...

I purchased a spare Piher trimmer and have sacrificed it to see what the construction is like, I would have preferred to see a carbon brush wiper but the track terminations look good. I had a look for cermet trimmers but couldn't find them in the same form factor.

I've found a way to stop the VUs banging against the end stops, after studying the regulator circuit and giving it a lot of thought I've bridged C103 (3.3 uF) with a 220 uF cap and this has slowed the rise time of the supply sufficient to stop the banging, it does not seem to have affected the stability. If anybody spots I've made a glaring error here please let me know.