Ambika SMR4 C26/27

Can I use a 500 volt (5mm) instead of the 50 volt (2,5mm-mini) Ceramic?

Yups, higher voltage isn’t a problem for the function (in theory it should prolong lifetime) but you may check dimensions. If its taller than 10mm its too big!

Going higher voltage is always risky with regards to to size. 500V is a lot so I would double check the size info is correct.
I’ll never forget the day I received a bag of caps that were the size of a lighter each because I hadn’t double checked the voltage rating.

I have some spare high voltage 1N caps the size of an Aircraft Carrier, if anyone is interested in TeslaCoil compliant caps, drop me a line… or you solder them in a circle and make some sort of CapHenge

@fcd72: That looks like an early prototype of CycliC, where did you find it ?

I searched the Garbage of Olivier Ancestors…