Plasma speakers anyone with info?

What anyone prefers is OK by me! My entire professional career in semiconductor processing / fabrication has been spent around an absolute AlphaBet soup of Chemistry. I will NOT have any Fluorine or Fluorinated compounds in my house.
With the possible exception of Floride Toothpaste!

While I believe in, and practice good sound, I won't take any chemical risks. Even Helium, an 'inert' gas and technically non-toxic (no chemical reactions) is an asphyxiant.

http://www.solvaychemicals.us/static/wma/pdf/9/8/4/1/Sulfur_Hexafluoride.pdf

Above link is for MSDS (Material Safety Data Sheet) on SF6

What info are you after? From your very brief post it sounds as if you want info on where you can buy a working unit.

Only TWO companies make and sell plasma tweeters - Acapella and Lansche. Both are German. Acapella used to sell the plasma tweeters individually but I think they now only sell them as part of their speakers. Lansche is the same, but they closed the door on tweeter sales many years ago. Unless I am very much mistaken, you will not be able to buy these from the factory.

I think that Brian Ackerman from AAudio Imports is a member of Audiogon, so he may be able to advise you on whether you could buy one.

Your other route is to DIY a pair. I have seen circuit diagrams on the web. My own skills are very modest - I can't even put together a doorbell kit from Radio Shack let alone tackle a project like this!!

Going on specs alone the Lansche is more desirable. The plasma flame is twice the size of the Acapella, consequently it can go lower - 5kHz for the Acapella, 2.5kHz for the Lansche. Neither unit tolerates low frequencies beyond the stated crossover point very well, so steep filters are necessary. The Acapella has a crossover built in - the point and slope are configurable by changing internal components. Not sure about the Lansche.

If you want to know what they sound like - I have a pair of Acapella Violons.

Amfibius' information coincides perfectly with mine. I would have a source for the a-Capella tweeters in Europe. No commercial interest on my side. If you are interested drop me a mail and I'll give you a contact address.

I heard the Plasma I at a hotel suite at CES in 1979. They sounded incredible - but the technology is what mesmerized me.

Best part of this was listening in on a conversation between Dr Hill and Dr. Oskar Heil - the inventor of the FET and the Heil Air Motion Transformer. Dr Heil showed up just after me, and the 3 of us listened for a while - Heil's first time listening to them or meeting Dr. Hill. The next hour was a long passionate conversation on the physics of sound from 2 of the pioneers. A pretty good day for a 19 y.o. kid.

It was Heil Plasmatronics. They burned a helium. $7k a pair in 1976. I actually heard them at a store called Absolute Audio in Santa Ana. Fabulous sound. The best speakersvI have ever heard. No cones to produce sound above 600 hz. Hence no distortion from lag time of paper cones . It was strange watching a flickering purple gas emit music. Impressive. The inventor is a laser physicist. They took them off the market as they posed a slight health risk.