How are Mallory 150 Polyester Caps vs Orange Drop Polypropylene?

I'm about to purchase coupling caps.

The little yellow Mallory 150's are polyester. The bigger Orange Drops are polypropylene.

I've read somewhere that polyester caps are bad. Is this true? Why?

The Mallory's are half the price, and smaller too, so I was leaning towards those, but not if polyester is terrible.

Thanks

Really nothing wrong with polyester, especially for vintage amps. I'd suggest splurging on CDE WMF polyester film-and-foil capacitors from Mouser. The orange drop is a better cap than the Mallory, but not due to the polypropylene - it is film-and-foil, vs. metallized construction, which is a nice upgrade.

jon_s said:

Really nothing wrong with polyester, especially for vintage amps. I'd suggest splurging on CDE WMF polyester film-and-foil capacitors from Mouser. The orange drop is a better cap than the Mallory, but not due to the polypropylene - it is film-and-foil, vs. metallized construction, which is a nice upgrade.

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Amen to that. . . . I couldn't have said it better myself!

The Mallory PVC Series are also film-and-foil (up to the 1000VDC rated caps), and the shield end is marked. Note that they're radial type caps and some mistakenly call them 'orange drops'. Sadly, the PVC Series has been discontinued and they're getting harder to find in the 'normal' values used in vintage tube amps.

The Illinois Capacitor MWR Series is also a very good cap for vintage amps. It's construction is metallized polyester film.

I used CDE WMF Series and Mallory PVC Series in my Scott LK72A restoration, and was VERY pleased with the results.

CDE (Cornell Dubilier) was making the Mallory PVC Series caps for a long time, and continues to produce Mallory brand caps such as the 150 Series.

Based on the construction-type documents I have from Vishay, the 715P orange drop is polypropelene, whereas the 716P high performance cap is polypropelene film and foil.

. . Falcon

Orange Drop 715P and 716P are Polypropylene, Orange Drop 225P is Polyester.
Mallory 150 caps are used a lot as guitar tone caps, and in guitar amps.....they have a "softer" sound than the Polypropylene Orange Drops.
Many builders use 225P Polyester Orange Drops also, to get a more "vintage" (softer) tone.


Steve

OK thanks for the advice on the CDE's, but those WMF caps, at 600v, are $8.50 each at Mouser. That's more than I paid for the amplifier. No way am I spending $100 on caps lol. I'm in the $1.00 each sorta price range.

Well these are decent.....and in your "price range" too?

Dayton Film and Foil Polypropylene capacitors......from Parts Express.

I used these as coupling caps (0.1uf/400v) in my Magnavox 8802 (6V6 PP) tube amplifier.