Natural dielectrics (in caps and wire) like silk, paper and cotton sound more natural

[BudP]

And I would exclude the special case of paper caps that are not hermetically sealed. Temperature and humidity changes will move their characteristics all over the place. The cult surrounding them is puzzling.

Were you including those molded in beeswax in your paper cap set? I can confirm the now archetypal story of a characteristic change in sound, when beeswax was used in cheap paper layer SE OPT's for Admiral TV's. Urine salts from a seriously inebriated Hispanic supervisor, applied directly to the hot wax tank, two hours after eating the local (Elmwood Park Bar and Grill) hot pastrami sandwich and drinking Old Milwaukee beer, were the key to winning and holding the Admiral business, ever so long ago.

The man was fired for politically incorrect attempts at "encounters" and then rehired, to provide his unique chemistry, on a part time basis. I was there.

Bud

[SY]

Were you including those molded in beeswax in your paper cap set?

Yes, they're horrible.

Great story. Sounds like Burger King.

[fdegrove]

Hi,

Generally speaking polystyrene and polypropylene.
Yet within that range it's perfectly possible to manufacture coupling caps that don't sound all that great just the same.....

Cheers,

[auplater]

Originally Posted by MJL21193

On the topic of dielectrics I did some crude tests last winter, looking for an easier/more effective insulator to replace mica on flat package transistors (yeah, no life). I thought about painting the back plate with something and I eventually tried waterbased polyurethane, thinking this could be applied thin, is tough and (I assumed) is a good insulator. The problem I had was applying it smoothly enough, as it dries very quickly it doesn't "flow out" like it's solvent based cousin. I gave up on the idea then, distracted by other things.

Thinking about it since, I have come up with another way - this time I will dip the whole device and let the coating drip off.
What do you suppose the dielectric strength of waterbased polyurethane is and how does it compare with mica or silicone?

Spin coating works wonders in the electronics industry... might give that a try...

John L.

[Wavebourn]

I prefer such rose pads made of beryllium ceramic, but here in USA they are unobtanium.

[zigzagflux]

Originally Posted by BudP

drinking Old Milwaukee beer

For shame. That was the drink of choice for poor college dormers. Makes for a horrible next day.