[sdiy] all analog FM synthesis?

[karl dalen]

 --- Theo <t.hogers at home.nl> skrev: 
> Jurgen Michaelis (off JoMoX) DIYed a analoge FM synth, the Nuronium.
> He has some WebPages about this unit (in German) on his personal site.
> Instead of VCO he is using self oscillating moog ladder filters.
> All 6 "operators" can modulate each other (5 modulation levels for each
> operator).

However, (i add this to my previous mail) doing the same with a 
ladder design it behaves erratic at very low freq, and i dont think
he is doing trough zero with the ladder, more of the regular variant FM!

Anyway, i think its also more adequate to use a filter in FM
then oscillators if you was about to process the signal too
at the same time! However any SY99 or SY77 user can test this
and quickly see that the spectrum becomes very harsh quickly
when modulating and processing a Fm wave.

In the SY99 you can sample a wave put it trough the
filter who FM the OSC, its not that satisfying in reality,
you have to muffle the wave by lowering Cf of the filter
almost all the way down to get decent results.  

Much like it  as you define it below.
  
Reg
KD 


> And in a effort to take FM a step further (away from being intuitive to
> program) all 6 operators can also feed audio into each other. 2 of the
> operators also take external audio inputs.
> I found the Nuronium sounds most useful when using more "simple" routings.
> When everything is modulating everything, everything sounds like everything
> else.
> 
> Theo
> 
> 
> ----- Original Message -----
> From: René Schmitz <uzs159 at uni-bonn.de>
> To: Synth-Diy <synth-diy at dropmix.xs4all.nl>
> Sent: Friday, February 18, 2005 8:21 PM
> Subject: Re: [sdiy] all analog FM synthesis?
> 
> 
> Hi Dustin, Paul and all,
> 
> Paul Maddox wrote:
> > Dustin,
> >
> >
> >>i have been very much into FM synthesis lately and i was womdering if
> >>it can be done analog? what i have looked at is a design for a quad
> >>triangle VCO. with lin and log inputs. and one have a though on this ?
> >
> >
> > this has been discussed on here before (can't remember when), I think
> > someone was going to have a go at building some. The big issue, IIRC, is
> the
> > 'reversing' of the output wave when the input CV goes negative.
> 
> The search phrase would be "through zero" fm (TZFM). Have a look at my
> site, for my take on analog deep fm. (VCO6)
> 
> Cheers,
>   René
> 
> --
> uzs159 at uni-bonn.de
> http://www.uni-bonn.de/~uzs159
> 
> 
>