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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
sniper9999
6 posts
 
Dear JAllen, it is not difficult to differential teflon from mylar, sophisticated equipment is not necessary. You just need to set a soldering iron to 270 deg. Celsius, and poke the tip onto the film, teflon can stand this temperature and mylar will melt like butter.
I am also interested in this cheap copper teflon and will buy a pair for evaluation from an authorized dealer here. Will let you know the results very soon. Stay tuned!!!
serengetiplains
3 posts
 
I purchased some Psvane capacitors a few weeks back and immediately returned them after measuring them. I have a QuadTech capacitance meter that measures DF to six decimal places. Teflon capacitors normally measure about 0.000100 DF ("100"), with the better among them measuring 20 and lower (I measured one at 6 just today). The Psvanes measured 5500, 5500 and 3500 for the three caps I measured. One dielectric that measures that terribly is mylar. Given the small size of the Psvane capacitors for a 600VDC rating, combined with the very poor DF measures, I assume they were mylar caps. (Physical size of a capacitor is determined by the thickness of the plate and dielectric. Dielectric thickness is determined by target voltage and dielectric constant. The dielectric constant of mylar is 3.5, which is almost twice that of teflon, which allows a mylar capacitor to be smaller than an equally rated teflon cap.)
jallen OP
502 posts
 
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
sniper9999
6 posts
 
To be fair I would purchase the caps from an authorized dealer, later today.
magfan
1,583 posts
 
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?
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