Polycarbonate as coupling caps?

[KrankKall]

I dug up a pair of ERO MKC capacitors, with the correct values, for an amplifier I am considering building.
I am NOT familiar with polycarbonate, nor have I ever used it before.
Are there any opinions. pro and con, as to the use of polycarbonate?

THANKS and y'all have a great 4th of July!

Steve

[jlsem]

It's one of many suitable polymers for coupling caps. There was probably a time in recent audiophile history when it was considered a ne plus ultra upgrade.

John

[the_manta]

MKC-Caps are among the best considering temperature drift. But dielectric absorption is worse than MKP. But in the AF Range this is completely regardless. There are much, really much worse dielectrics like paper in oil, wax etc.
There is no problem using these MKC's. They'll work fine.

[jacco vermeulen]

Originally Posted by KrankKall

ERO MKC capacitors

size advantage (and cheap nowadays)

[KrankKall]

Thanks everyone for the information, it is greatly appreciated!

Steve

[piano3]

Is it true what is said about caps with polar dielectrics working best with a relatively high DC voltage across them?

[AndrewT]

the polycarbonate film of the type used for capacitor production became obsolete (they for whatever reason stopped making it).
As a result polycarbonate capacitors became obsolete. They were among the best available at reasonable cost. Far cheaper than Polypropylene at that time (80's to 90's) and yet almost as good. Far better than any of the MKT and MKS that have been used since.

I would not be surprised to hear that a few specialist cap manufacturers are still making polycarbonate capacitors but using old stock film or unsuitable film for current production. Be careful buying "new" polycarbonate capacitors.

[jlsem]

Polycarbonate has been largely replaced by polyphenylene sulfide which has the same operating temperature range but lower dissipation factor and higher insulation resistance.

John

[jackinnj]

Originally Posted by jlsem

Polycarbonate has been largely replaced by polyphenylene sulfide which has the same operating temperature range but lower dissipation factor and higher insulation resistance.

John

Polyphenylene sulfide caps are available as surface mount. You can stack a bunch of 'em and get 10u in a wee bit of real estate.

Polycarbonates are great for timing and sample/hold.

The late Bob Pease had a great cap treatise which is on National Semi's website.

[richwalters]

Originally Posted by AndrewT

the polycarbonate film of the type used for capacitor production became obsolete (they for whatever reason stopped making it).

Pure and simple.......Environmental reasons. However all this environmental protection stuff is a hyprocrisy as Tants continue to be used by the million in mobile phones....

Note of caution.....I recently repaired a tube amp which had a polycarbonate cap across the mains input and oozed.....NO!! they aren't reliable in this application. polycarbonate caps aren't suitable as X rated.

richy