They're a fairly normal stacked film capacitor, but are 'uncoated'. That's what many box shaped film capacitors would look like with the plastic case removed.
Most of these were made by Siemens or EPCOS (its successor). They're still made today, here's an example.
Most of these were made by Siemens or EPCOS (its successor). They're still made today, here's an example.
That is my ignorance. It is like Vishay naked resistor.
Vishay VAR-Series "naked" Z-FOIL RESISTOR
Roushon.
Vishay VAR-Series "naked" Z-FOIL RESISTOR
Roushon.
Sprague and Siemens made stacked film parts in the 80s. The Siemens parts had a blue epoxy coat on the ends to help keep the leads from falling off when soldered, a common affliction with the stacked film parts of those days, as well as some of the ceramic multilayer caps, which were just chip caps with leads tacked on and dipped in epoxy (still are, but they're generally better made these days). At any rate, the parts shown might be old stuff from Sprague. I just picked up some old 220nF stacked film parts (probably Sprague) this weekend... Epcos still makes some stacked film capacitors - I just recently bought a bunch for a project at work. Panasonic may also still make them, though they coat theirs with their usual brick-red epoxy - check Digi-Key.
Edit - Having looked at the parts in question again, I would guess that they're old Sprague parts, as the leads aren't too well anchored in the end metallization - probably the reason for the tendency to fall off when soldered. Be careful. Otherwise, good parts with low ESR and ESL (though they are polyester - Siemens made some polycarbonate stacked film caps back then, but I believe all the currently manufactured stacked films are polyester).
Edit - Having looked at the parts in question again, I would guess that they're old Sprague parts, as the leads aren't too well anchored in the end metallization - probably the reason for the tendency to fall off when soldered. Be careful. Otherwise, good parts with low ESR and ESL (though they are polyester - Siemens made some polycarbonate stacked film caps back then, but I believe all the currently manufactured stacked films are polyester).
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wrenchhone, I think for the most part your answer is correct, except that the (old) Siemens parts I have look exactly the same.
Well, they also made parts with a blue epoxy coating on the ends - maybe those were the polycarbonate parts. There's a bin or two of them at one of the local surplus stores in my area.
Hy stefanom,
my two cents....use them in analog PSU bypass or signal decoupling, but leave ceramics in digital....
ciao
marco
my two cents....use them in analog PSU bypass or signal decoupling, but leave ceramics in digital....
ciao
marco
That depends on what you are bypassing and why. For bypassing digital spikes you probably can't beat the appropriate ceramic cap - which your unit probably already has. Note that in some cases high ESR is a requirement for this application.stefanom said:
As others have said, what you have there appear to be bog standard polyester caps. Will be low inductance and low ESR, but perhaps a bit nonlinear like polyester usually is. Fine for decoupling where these characteristics are appropriate.
All my old polycarbonate capacitors looked like that.
I never saw any polyester caps in that form.
I thought they performed very well. I could not afford (the far more expensive) polypropylene at that time.
How prices and availability have changed.
I never saw any polyester caps in that form.
I thought they performed very well. I could not afford (the far more expensive) polypropylene at that time.
How prices and availability have changed.
If one laid these down on their sides, would they make big non standard SMD caps?
Would the ESL and/or the ESL be even lower?
Would the ESL and/or the ESL be even lower?
Those are old Epcos/ Siemens stacked PC film , very good for PSU bypass (used in Kebschull pre), many old high end CDP/ DAC use them as decoupling on TDA1541. Not that good for dc blocking, sound wise that is
Inductance will be higher due to the physical arrangement.
COG ceramic SMD caps are about the best you can get.
COG ceramic SMD caps are about the best you can get.
I should have said the inductance is a problem for bypass use.
I found some interesting non-polarized audio caps for DC blocking. They are not the old style back to back polarized caps, but actually designed as non-polar. If you are upgrading an existing design they may help.
I will have to wait until I get home to get the line name since I can't seem find them in Digi-Key right now (I am at work).
I found some interesting non-polarized audio caps for DC blocking. They are not the old style back to back polarized caps, but actually designed as non-polar. If you are upgrading an existing design they may help.
I will have to wait until I get home to get the line name since I can't seem find them in Digi-Key right now (I am at work).
there are myriad of good sounding coupling caps, how good they sounds depends on your preference and the whole system of course. My trick is using what I have in my drawer and try them one by one, be it paper in oil, mkp, mks, etc. I visited junk shop now and then and grab used parts just to try, if lucky I can get good sounding caps
Last night I put them in my CDP. Parallel to ELO caps around decoder and DAC. Replacing the stock ceramics discs.
Gonna try them for few day, see if i like 'em.
Gonna try them for few day, see if i like 'em.
These stacked foil caps are good for lowish inductance, not the opposite.
These stacked foil caps are good for lowish ESR, not the opposite.
That makes them bad for decoupling where there are other capacitors nearby.
These stacked foil caps have very low leakage. That makes them good for DC blocking, not the opposite.
These stacked foil caps are good for lowish ESR, not the opposite.
That makes them bad for decoupling where there are other capacitors nearby.
These stacked foil caps have very low leakage. That makes them good for DC blocking, not the opposite.
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