The 50+50 UF unit will be fine.
I know this is over the top, but when I have to replace capacitors I will often cut open the original and "re-stuff" it.
While originality is important, a cap that doesn't "capasitate" is worthless if you have any thought of actually using the gear. And, as I'm sure you know, capacitors don't last forever and must be replaced to preserve the functionality of the gear, not to mention reliability.
All this is mostly with collectable HiFi gear. With vintage studio gear it doesn't seem to matter to most people.
Now, you don't have to repeat my insanity with the re-stuffing. You can always hide the new cap under the chassis and leave the original one in place for looks.
Originally Posted by DanDan
I hear you. Others have advised the same. I changed them some time ago, I think because one of the old ones had snapped off. That's my story anyhow....
I sold the amp today for €1200 to a guy fairly nearby. I am apprehensive about the swollen, physically leaking cap though.
I told the guy I would install a replacement in the future.
It is a Plessey unit, the original.
40 plus 40 MicroFarads. 500V.
I have a 50+50, 500 V, new, no name, physically shorter but same diameter.
I would have thought 50 is better but could some valve expert let me know if this is OK or not please?
Also, if 40 is mandatory, where to get that hens tooth?