Mixturtrautonium (more details)

[Martin Czech]

Nice to see that someone cares about playing style in these rompler
days. Such a wire makes a difference.  I have Trautonium pieces on CD
(Synthesizer von gestern or synthesizer of the past, if you like), do
you have the original Oskar Sala stuff from Erdenklang label?  Do you
recommend buying it then ?

By the way, Sala seems to use also two footpedals.
Do you want to use something like that, too ?



> One ramaining problem:
> I don't have any idea of who to build a subharmonic 
> oscilator with 1/2,1/3,1/4 ... and/or 1/24th freq of the 
> master oscillator, generating sawtooth waves, all with the 
> same amplitude. 
> My only idea is using a microprocessor, but
> Oskar Sala build his instrument in the 30th, with tubes
> (Surely without microprocessor).
> Any ideas ????????????????????????????????????????????
> 
After so many questions some help:

It is simple. (Sala's patent works with syncing the relaxation oscs,
it's all tubes. Today we don't need that). Your top osc needs to have
saw and sqa wave.  Divide the squa wave by 2. Add the saw wave. Turn
the amplitude down by 0.5. Voila! Saw wave with 0.5 times the frequency.
Now you understand the basic principle. It is all about generating
a n step staircase for the saw with frequ. 1/n.

Digital:
Now divide top osc. sqa by 2/4/8.  Draw all these pulse trains on a piece
of paper, the top saw wave below. It is now easy to guess the logical
combination of those signals which give pulse waves so that adding the
pulses to the saw will give 1/2 1/3 etc.

Analog:
J.H.'s voltage controlled divider uses analog staircase patterns (a
short current spike into an integrator makes a staircase, from LM3900
app. notes). You need a comparator to reset this thing after the last
step.


By the way: the sound on Sala's recordings is also influenced by pitch
and frequency shifting devices.

Keep us informed!

m.c.