Just bought some of those Russian paper/oil caps off of ebay

[aletheian]

Here are some pics of on e dissected. I didn't learn too much since I don't know what oil impregnated paper looks like, but there are layers of aluminum foil and waxy looking paper.

[aletheian]

here is another pic

[tomtt]

somehow i felt that oil+paper would drip when disasembled

let me check...

http://www.cs.joensuu.fi/~jkettune/Cats/Shite.jpg


i cant tell

cap porn....
(click on pic)

http://www.ektypus.de/nos_kondensatoren.html

[Ivan Mironenko]

Its just metallized paper capacitors. Nothing special, except they are very cheap

[aletheian]

Originally posted by tomtt
somehow i felt that oil+paper would drip when disasembled

That is where the line blurrs. as i understand it...TECHNICALLY, an electrolytic capacitor is paper in oil... aluminum plate material with a paper dielectric either impregnated or coated in electrolyte. They are called "dry" even though some of them contain moist material. Some caps are immersed in oil... like in olden days, and I dadre say that oil FILLED capacitors like motot runs would possible drip. But many paper and oil caps are made with kraft paper that has oil or wax mixed with the pulp before it is pressed, so I dunno how many HI-FI caps are that way, and how many are actually saturated afterward in "oil".

[aletheian]

Originally posted by Ivan Mironenko
Its just metallized paper capacitors. Nothing special, except they are very cheap

Gotcha... well that's actually cool, I can use them in the place of the mylar/paper Balck cats and black beauties that I have been using. The Cats had inductive leads anyway, but I just looked the other way on that because I liked they way they sounded.

[Sheldon]

Why would ferrous leads be inductive? I'm no expert, but I needed to check inductance for an application. The formulae for calculating lead inductance don't have any term for different wire compositions, only length and diameter.

Sheldon

[anatech]

Hi Sheldon,
It depends on the frequency as to whether the lead inductance is important. Generally not at audio frequencies, unless the circuit responds at high frequencies as well.

-Chris

[aletheian]

As I understand it... and I am no expert... inductance can be boiled down to the capacity to store the magnetic field of a signal, so it has a reactance, like a capacitor does, but backward at a perticular frequency. So a copper clad steel lead will suffer from the 'ol skin effect, where the signal reacts to the different resistances of the two materials at different frequencies, resulting in reactance in the audio band... well into the audio band , sucking the low end, depending on the length and composition of the wire. The loweer the frequency, the less skin effect, so that is why the bass suffers in clad steel wire.

another consideration id parasitic oscillation that heppen outside the audio band. If the inductance is minimised, so is the ability of the lead to cause a ringing when it's Q is excited in conjunction with capacitance.

There is also apparently hysteresis losses in ferrous materials... energy wasted because of magnetic fields and whatnot, but I don't know anything about that stuff, I just nod to the experts

[Jaka Racman]

Hi,

If I were you I would worry more about possible polychlorinated biphenyl content in those caps than about ferromagnetic properties. PCB was used in my country up to the early 80's in capacitor manufacture and we had quite an affair because of the unadequate waste disposal by the factory.

I do not imply that those caps contain PCBs, but if they are NOS, that is possible.

Best regards,

Jaka Racman