Psvane Teflon capacitors real or fakes?


These are great looking capacitors and supposed to be competing against the Audience, Rel, V-Cap, and Sonicap Teflon capacitors. A couple of my tweaky friends who have no end to new capacitors gave them a try and had one quit after a month or so, and with the wire cut off, no return possible. So they cut it open, yes they are curious, and according to them, the guts looked like mylar, measured like mylar??? Could these not be Teflon caps after all??? I open this for discussion with some of the tweaky electonic minds out there to get to the bottom of this. If they are not genuine teflon, I would not want fellow audiophiles to get ripped by another false claim. But to be fair, real verifiable data should be submitted here, no guesswork. I trust my friends, but I did not do the test, so I open it to other philes. Hey, I like a great deal too, but if it is not as advertised, I get pissed too. Take a look fellow philes, and lets solve the mystery....Jallen
jallen
Greetings,

I received the test measurements from my friend and he stated similar findings. The 0.1 600V Psvane caps were measured using method F.T.I.R. Fourier Transformer Infrared Spectroscopy, and the material was determined to be polyester (ethylene terepthalate) and the D.F. test at 1Khz was .005, strongly suggesting mylar inside. When he exposed the material to a soldering iron and heat gun, it melted....doesn't sound like the teflon I know and love.
I will be anxiously awaiting your findings....jallen
Teflon is 'soft' to the touch compared to mylar.
If the mylar is the same as in a space blanket, it'll be 'crinkly' and harder to the touch. It may feel slick, too. Teflon may even stretch....though I've never messed with it in quite that thin a pices. Mylar shouldn't stretch.

The measures above? Good stuff and seem to indicate mylar.

for Serengetiplains: Isn't surface area tied in there as well?
Magfan, yes, you're looking at total surface area as one factor determining overall capacitance.
A note of caution from an old fogie.

270 C and teflon do not mix well. As I understand it, teflon begins to decompose and form HF, a very bad chemical. HF symptoms can develop over 24-48 hours, which makes it particularly insidious. In my experience, expect sore throat and a sudden onset of arthritis in your soldering hand. Also in my experience, if the exposure is very small, symptoms disappear in a few days or a week. But why tempt fate? Read the MSDS.

With a teflon dielectric, I like to keep soldering temperatures below 250 C, and even then I like to solder at eye level, so that harmful vapours go up. Good air flow doesn't hurt much either.

Read that MSDS.