There are 2 fundamental differences that need to be taken in to account when replacing “vintage” caps. And I use the term vintage loosely. One is tolerance. In the worst case I can remember a capacitors value was +150% -%100 tolerance. The means that for a 1 uF the measured value of anything between 2.5 uF to .1 uF would be considered “in spec” old radios still amaze me they ever worked. Now a days +-20% is the normal. The service manual will tell you the tolerance of the filters. From memory I am guessing it is going to be +100% to -20 % so pretty wide design tolerance on the filters.
The other important spec is the voltage rating of the cap. And here vintage caps and modern caps differ greatly. Vintage caps were very tolerant of over voltage especially given how tube gear warms up before the tube’s comes in to operation the B+ will spike some times as high as 200 to 250 volts higher then when the device is operating and can hang there for about 15-30 seconds. This is not an issue in your 475 as it is solid state. However modern caps are completely intolerant of over voltage so if you have the physical space it is always good to bump up the voltage rating of the cap it wont effect anything to replace a 63V cap with a 400V cap excepta little cost in $ maybe one or 2 and physical space it will be slightly bigger then it’s modern lower voltage counterpart. However both are usually smaller then their vintage counter part even doubling the voltage the modern can will be smaller physically.
On 5/29/2020 12:50 AM, ciclista41 via groups.io wrote:
It might help if I posted the values of the capacitors that were originally in the scope. I'll do this below in the quoted text.
I have used Kemet in projects but mainly their surface mount stuff
I tend to lean to
Rubycon - Actual (frequently found counter fit parts)
and Illinois Capasitor