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Re: [TCML] tcs as musical instruments...

Yeah Mike, good points indeed. But hey, it's not like Tesla Coils are trying compete with speakers and such. The fact is it's just a fun thing to do midi on DR. To like play some Zeppelin on a Tesla Coil. Granted it's not fidelity, but it's still cool to do it. And some songs come out awesome where others really suffer. It just depends on the notes and frequencies. Phils controller has a volume adjustment during midi that I find fabulous. I've learned that more volume equates to more RF cycles and thus better sound. One problem with that is more volume also means longer spark lengths and in an environment where you have no more room, oops.. I covered up my rafters with chicken RF grounded today.. well, basically it ended up as a giant target.. sure rafters are now safe but spark formation is blah..... Jeff Larson mentioned maybe just forming poly around the rafters and stuff.. I think I'll try that route...

Anyway, I tried to play some Jimmy Hendrix today with the rafter chicken wire thing.. It kind of sucked, but hey... we learn by doing..... not by arm chair cowboy'ing Tesla Coils... this midi kind of sucked. One thing about midi, the coil is at the mercy of the midi itself...

http://www.youtube.com/watch?v=3JTw287YtAs&list=UUKTGJZAkKZlDLVS7g-9dIsg&index=1&feature=plcp <http://www.youtube.com/watch?v=3JTw287YtAs&list=UUKTGJZAkKZlDLVS7g-9dIsg&index=1&feature=plcp>

Take care,

On 3/31/2012 12:23 PM, Michael Twieg wrote:
There's not a huge amount that can be done to change the tone produced by a
DRSSTC.  The peak-to-RMS power ratio they put out is very high, giving a
sound that has many strong harmonics.  This is especially bad at low tones
but not so bad at high tones.  This phenomenon is determined by the physics
of how arcs form and give rise to sound; the breakout of an arc will always
be sudden and powerful, and there's no real way to soften it (I have to
mention that Steve's QRSSTC designs do this somewhat, but so far the QRSSTC
doesn't seem to be suitable to music due to it low rep rate).  Simply put,
highly distorted sound is built into the physics of the DRSSTC.  And while
polyphonics are possible (either using one large coil or several separate
coils), the result will always be underwhelming because the combined output
will be polluted with tons of harmonics.

Amplitude modulated CW coils are capable of generating very low distortion
sound, but they are monstrously inefficient, I kind of wonder if you could
get a decent tradeoff between distortion and efficiency by operating a
amplitude modulating a CW coil like a class B or class C amp.  But I
imagine it would still end up being too efficient for real performances.
And CW coils are generally less impressive visually, compared to high power
DRSSTCs which produce very long arcs which act much more "lively" than the
arcs or plasma "flames" generated by CW coils.


On Sat, Mar 31, 2012 at 5:16 AM, Finn Hammer<f-h@xxxx>  wrote:

Jim, all

I almost choked on my porridge this morning as I read this mail of yours,
and my first thought was: "Where have you been these last 8 years?"

The idea of using a DRSSTC as a musical instrument was originally mine,
as you ought to know, and I presented it to Steve Conner at breakfast at
the Derby Teslathon back in 1994. He liked the idea, and modified a
Roland synth. so that it would act as a combined MIDI interpreter and TC
controller for all 6 channels.
http://www.youtube.com/watch?v=L9Jjsv2zr-c [
I went on to create 6 identical DRSSTC's and the rest is history.

This was a time where both Daniel MCauley and Stephen Ward went public
with comments like "We don't think there will be any interest in the
harsh sound from a pulsed TC"

Meanwhile, the Bach video was recorded, with a cheap snapshot digital
camera, so although the microphones clipped, and the echo in the
industrial hall was total, the sound was awesome.
Here you have _real_ 6 note polyphony, 1995 style, never done before or,
for that matter, by anyone after:
http://www.youtube.com/watch?v=VOXygoQkXsQ [

You brushed up on the lack of volume at low frequencies, here is Thumper
@68Hz. the key to volume lies in input voltage, a parameter it should not
be too hard to controll.
http://www.youtube.com/watch?v=l-FAdM_5E-s [

Different voices are easy to produce, just sit down with the synth and
press the different instruments, some good some awfull, I particularly
like the stuff from 0:58 to 1:19 and forward
http://www.youtube.com/watch?v=Vrtu4uolTVc [

Simple pulse trains can produce interesting sounds like this V-Twin
revving up:
http://www.youtube.com/watch?v=W0scx1WD3sU [

And the sound of a MIDI saxophone is also interesting:
http://www.youtube.com/watch?v=ANiKSPtwTVc [

So you see, pulse trains, envelope curves controlling the ON-Time and
input voltage controll for macro volume changes, It's all been done, and
is just waiting for some young whizzkid to perfect.

Cheers, Finn Hammer still lurkin'

----- Original meddelelse -----

Fra: Jim Lux<jimlux@xxxxxxxxxxxxx>
Til: Tesla Coil Mailing List<tesla@xxxxxxxxxx>
Dato: Lør, 31. mar 2012 03:47
Emne: [TCML] tcs as musical instruments...

As I was driving to my daughter's rehearsal this afternoon, I thought
about Bart's videos (and all the other musical TCs).. and realized
we should think about what kind of instrument a TC is, and my best
is that it's sort of like an organ that can play only one note at a

There's not much in the way of dynamics. You have to have enough
to get a breakout, and the sound from a small spark is not a lot
different from a big spark. So it's like a pipe organ in that way.
get big changes in volumes by adding ranks of pipes.

Can it do polyphony.. I think so, in a limited way. You're basically
generating a pulse stream. And I could logically "OR" two pulse
streams, one at "C" and one at "E" for instance, and I should hear
notes. Easy to test with some .wav files

How many octaves range does it have.. you can go pretty low, but the
loudness will drop off. The bang size is roughly constant, so the
acoustic power as the rep-rate goes down goes down with frequency,
Weber-Fechner law means that lower frequencies "sound" less loud for
same power. What's the top frequency, maybe a couple octaves above
middle C?

Can we make a TC put out a sound that's different than the sort of
we normally get. Perhaps, if you send closely spaced double pulses?
What does something that is, say, bang, 1 ms, bang, 9 ms, bang, 1ms,
bang,... sound like.. Yes, about 100Hz, but there'll be some
harmonic structure that would sound different. Then there's all the
techniques from early synthesizers: Two pulse trains at the same
frequency, one with a bit of FM on it (a sort of vibrato/tremolo

But here's the intriguing thing.. I've always wanted to build a setup
with multiple TCs that can do real polyphony. Originally, I had ideas
of multiple rotary spark gaps a'la a Hammond organ and tone wheels
(someone actually did this at the turn of the 20th century, I have

And, because I'm a spark gap kind of guy, I started building a
triggered gap.

but these days, the DRSSTC is SO much more controllable.

If you could control the RF phase (which I would imagine you could,
clever timing), you could phase multiple coils so that sparks would
preferentially strike between toploads.

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