[Radioroslyn]

So I'm thinking on a transformer set why do you need them at all? Certainly if it's to block or filter rf noise from the ac line the relativity large inductance (at rf frequencies) of the primary should eliminate that issue right? With caps on both sides of the AC line no matter which way you plug it in to the socket there is some small leakage or coupling so if the chassis isn't at earth ground there is some low voltage AC there which can give you a little tingle.

On an ac/dc set (transformerless) I presume that it is there to filter rf from the ac line. Have built many p/s over the years and don't think I've ever used any caps on the line on transformer's primary. So enlighten this untrained long time hobbyist.

Terry