Vintage caps identification (with pics).

[Dingleberry]

Hi.

I was cleaning out my stashes and found some caps that I don't have clue about them.

Are those clear coated caps polystyrene/styroflex caps or just regular random film caps?
And what kind of caps those yellow block shaped caps?
Some film caps?

I know that that one 100nf is mustard cap and 680nf ERO MKT 1813
is a Roederstein metallized polyester cap. That should be good for cathode bypass cap and the mustard probably good for any audio purpose.

If any of you know anything about those yellow caps please be free to share your knowledge.

-T

[David Root]

The aluminum cans all look like polystyrene to me. The rectangular yellow cap next to the 47nF styrene (not the ones with Phillips on them) looks a lot like what Ampeg used in the '70s, at least in the SVT.

[Structo]

Yes I have a few of the polytyrene like you have there.
I want to try them in the treble and bright circuits to see how they sound.

I wonder what that green one is on the bottom.

I find it fascinating all the materials that they have made capacitors out of over the years.

They've come a long way since the old Leydon jar.

[Dingleberry]

The green one is 680nf ERO MKT 1813
It is a metallized polyester cap made by Roederstein.
From sixties or seventies. Got them from my Dad! He's a cool guy.

Should be probably good for cathode bypass position for example in Marshall-type amps, as far as I know.

-T

[Aurora]

The yellow block cap is metallized polycarbonate film caps.......

[Noel Grassy]

^Yup.
Found in early fuzz faces.

[Dai H.]

The yellow block cap is metallized polycarbonate film caps.......

hi, do you have a source for that somewhere? I'm asking since I'm trying to figure out which ones that look like those are metal. poly. and polycarbonate.(Or, is that specifically referring to the one with "MKC" marked on it?)

re: the "100nK KT", KT = polyester. The 47nF125V I would guess is polystyrene. Just because a cap is transparent looking, it does not mean polystyrene necessarily. Some polyesters, metal. poly. are clear, I have some polypropylene that are transparent but gold (coloured copper foil), which might appear to be polystyrene but are not. Polystyrene also, is not always in the "clear" package. Some are boxed, some are yellow, some are black. Some old ones seem to have a piece of paper with the markings in them.

[Noel Grassy]

Dai,
I don't have any idea of those cap's make-up. I just meant older Fuzz Faces
used a yellow cap with hot stamped I.D. markings. I have a few of them in
the 2.2µf 400V size and they are almost as big as a bar of soap! Just as
clean sounding too. Probably make a nice HiFi amplifier with them in
there.

I'm guilty of presuming any cap in an xparent package is Polyprop, and
the like. It's foolish I know now.

Noel Grassy.

[Dai H.]

Noel,

the Fuzz Face ones, I think those were(are) metal. polyester AFAIK. The thing I'd like to know is if the "341" means metal poly., the series no., etc. The earlier ones (to my knowledge) have stamped markings, but later they are (embossed?)--where the lettering is indented into the cap. One general clue seems to be metallization. Seems metallized films are more volumetrically efficient to the point where today, metal. polyester caps can be quite small for their capacitance.

[dynaman]

We must shop at the same mall......

[Dingleberry]

Wow dynaman. That's cool. "Cap-bonding". It's nice to see that I'm not the only cap-a-holic here...

-T

[Cliff Schecht]

You guys think you have a good cap collection? You guys haven't seen my stash! I need to cut down on what I have, it's starting to take up too much room and a lot of the stuff I have is pretty useless or "expired" (by date and/or ability to operate safely). You guys of course will get first dibs when I start selling stuff off or giving stuff away. (the safely operating stuff that is).

People like to dump their old electronics parts on me because not too many others dwell in the past like us audio guys and a lot of what we use is pretty application specific. A lot of the Stancor iron I have was given to me simply because it's bulky and heavy and takes up too much space. Of course I gladly take it .

I did recently stumble upon a huge collection of Western Electric silver mica caps too which have me intrigued. I've heard others describe them as mellow and I'm pretty sure I have just about every value I would ever need for an amp. The only downside is the caps are rated for at least 1kV so they are all HUGE. I might try them in something goofy though, who knows how they might sound. They look like the ones below, but the bigger ones are a darker Bakelite type color.

[img:400:300]http://www.cliftonlaboratories.com/user ... ate185.jpg[/img]