Tech Stuff

On this page I will have various topics on restoration and repair work, why some parts that are coveted by the audio world need to be exorcized! or maybe a better word is EXPOSED! Among other random ramblings from my daily mumbling under my breath.. Have fun, I do!

If you would like to know more about caps here are a few links I found on the web:

and if you really wish to go technical here is a good read:

Another infamous cap "Black Beauty"

Another infamous cap “Black Beauty”
Why does my amp sound bad, maybe even no sound at all or smoke!

Why does my amp sound bad, maybe even no sound at all or smoke!

This is a new (never used) “Black Beauty” I have dozens of them, they can command a high price on Ebay.. but look at the test results!

Here we have the pictured “Black Beauty” NOS under test. Look at the leakage in micro amps. 51.4 that is one hell of a leaker..I would never put that in any of my circuits..

6 Responses

  1. those black beauties were/are very bad for leakage. polycarbonates are better. then polypropylene. they dont leak. the transfer function of those two is excellent. the metalized vdersions tend to self heal from shorts also and stay stable.

  2. You are very correct Bob, I use a myriad of film/mylar type caps in my work..configurations depond on the sonics I’m going for or best type for that circuit design

  3. I have a dynakit stereo 70…what upgrades and tube replacements. I’d need a basic wiring page to show me where to replace the black beauty. I will buy everything from you. John

  4. Hello John, Thanks for your interest in our offerings. We however do not sell parts, we provide the full upgraded package done here at our facility. This assures you get a quality working and fully tested finished product including our final personal listen before shipment


  5. It’s so refreshing to see someone from the sudio community debunk some of the outlandish myths out there. The black beauty is a perfect example. Another is the “bumble bee” caps. I wish I had a nickel for every one of the hundreds of those I’ve disposed of over the years yet seeing them go for $10 or more a piece on the auction sight is comical. Then there are the $100 power supply bypass caps and $300 cables. My brother is an audiophile . . .we can’t discuss components, as you might expect.


  6. Thanks John for the nice comments.. Oh I’m fully aware of some of the “audiophile” claims with some of the tweaks.. although a few have some merit..most do not. Yes, the Bumble Bee’s and Black Beauty’s for the most part are horrid, they were ok when new issue, but flat out go bad with age in use or not.. I could get rich selling the thousands I have around here (both take outs and NOS) at 10.00 a pop! but I can not sell them it would be dishonest. I keep them around in a big collection glass jar ( 5 gallon glass water bottle)

    Cheers, Pat~