Do not mess w HF if you do not know what you are doing! |
I am afraid some distributors have been deceived about this product, along with consumers. I would like to hear about what Grant Fidelity and Parts Connexion have to say on this matter at this point. Both have great reputations to protect. I wonder if competing entities have evaluated them...Sonicap, V-Cap, Rel, Audience, etc. I would love to hear their comments but understand the reluctance to avoid a net verbal brawl.
Great info. sniper9999, thanks, jallen |
Sniper9999 do you feel at liberty to disclose which authorized dealer you purchased these from? |
The Psvane caps I got from the authorized dealer is definitely NOT teflon, the DF is soooo high, and sonically it lacks teflon's clarity. Another fake product from China. |
HF....also known as HydroFluoric Acid is REALLY bad news. In the body, it attacks CALCIUM which is pretty much what bones are made of. Thus, the potential arthritis makes some sense.
There are both liquids and gasses which have HF in them.
People exposed to hi-doses....such as people who work in the semiconductor industry, get calcium shots. This is some painful shit.
HF is used to etch silicon.
Teflon is used all over the semiconductor processing industry. Cassettes and ways to move wafers while exposing them to liquid acids are almost uniformly Teflon, though Polypropolene also is used since it is solvent proof. |
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. |
Magfan, yes, you're looking at total surface area as one factor determining overall capacitance. |
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? |
To be fair I would purchase the caps from an authorized dealer, later today. |
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 |
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.) |
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!!! |
Not sure how to post pictures in the forum - but here are the links of the pictures posted to our website.
http://shop.grantfidelity.com/Psvane-Copper-Foil-Teflon-Film-Caps-0-47uF-600V-pair.html
click on image to enlarge.
I have seen many many knock-off products in China including Solen caps - but if someone actually counterfeit Chinese caps now, high end audio is about to become a mine field :)
Rachel @ Grant Fidelity |
Where did your friends buy the Psvane caps? Can you post their pictures?
I have just cut open one cap from our stock and these are the pictures - I am no plastic expert but the film does look like teflon, to my eyes.
I put the pictures out for everyone to see, maybe some plastic expert can share some opinion.
How did your friend(s) measure the film coming to a conclusion 'measured like mylar'?
We have been dealing with the people at Psvane Audio for tubes and caps for years. I met the owners and it has never come across my mind even remotely that they could outright lie. Our tube amp tech have these installed into 845 amps and have been running it over 6 months with no problem at all.
If a seller refuse to take return of caps with broken lead, that's understandable. Failed in 30 days? That should be covered by warranty. |
