Beethoven's ninth played on two tesla coils !!

[Doodlebug]

I am building a medium sized Tesla coil and found this which
gobsmacked me.......
https://www.youtube.com/watch?v=Gd8Xckc536o

The two discharges are modulated to sound different notes

[Refugee]

I bet that came over well on any AM radios that may have been on close by.

[Nick]

Dual (or even rooms of) DRSSTCs (doubly resonant solid state Tesla coils) playing midi files are pretty common - a few years ago I specialised in building miniature DRSSTCs with some novel features - the threads are all on 4hv.org

Lots of videos on YouTube for these. - they are great fun to design and build.

I also designed a pretty awesome electromagnetic can crusher built round a large low-esr  high voltage capacitor bank - also all on 4hv.org. It was scarily good at launching aluminium hard drive platters so violently that they stuck in the roof of the barn I used for testing...

HV toys are good (if you are very careful and respectful, plus know what you're doing and your limitations).

Is this a third-party design or your own?

EDIT: DDSSTCs are mono-phonic, so in this case there should only be two simultaneous notes - this video has been messed around with - there is a backing track, so it's not just the Tesla coils - they cheated!

[Doodlebug]

Nick, can I run some idea past you as you are experienced in HV etc.

I have just bought 2 GU-81m tubes (I luv big glowing valves!).
I was going to use in parallel to make a plasma speaker but had this idea.

As you know plasma cannot reproduce bass.

I am thinking of making 2 separate plasma speakers, one fed with direct audio
and the other with delayed audio.
In this way, although still lacking bass, the sounds produced
might be more  colourful and interesting to listen to.
The distance between the two plasmas could be varied to change the
echo characteristics maybe.

Any thoughts, please?




I

[Nick]

I did build a gu81 VTTC some years back but not as a plasma speaker - I have built a class E solid state plasma speaker - not my design - it was an Eastern Voltage Research one running at 4MHz.

It sounded dire - very squeeky and hissy...

They also produce enormous amounts of ozone - I wouldn't make one today...

What design are you using?

I'll have a think about your idea...

[Doodlebug]

I 've listened to much of the plasma on utube and they most all sound hissy etc  as you say,
and no bass.  
Hence my idea to try to broaden out the sound interest.
I can imagine 2 plasma players, one at each end of the room with the audio delay I mentioned.

If I could play the piano etc or Midi I might go for the playing SSTC but I do
like big bright valves, reminding me of those glowing bright emitters of days long gone.

The two GU81's were not too dear to buy .  Here's the Czech circuit I might use....
Nice and simple for me to make. (I am fully aware of the dangers with MOTs,  BTW)