Doepfer

The part of this circuit that does the conversion seems pretty  
straight ahead and looks simple enough to make as a stan-alone module.  
If one was needing to make sines and had a triangle VCO already (that  
made a decent Triangle wave) then a converter module would work fine -  
a bit esoteric for mass production though.
-James

PS - sorry to all for starting this thread with my Z3000 post. I had  
my questions answered a long time ago.


On Dec 2, 2008, at 10:38 AM, laryn91 wrote:

> Sorry, I missed the "will" part :-p
>
> I had this link to the Aries VCO in one of the posts on this  
> (endless) thread. This is an
> excellent tri-to-sine converter (I can't hear any additional  
> overtones). Better than the more
> common 3080 converter and significantly better than your diode  
> converter. Aries claimed
> to produce <1% THD.
>
> http://www.leinermedia.net/aries/AriesSchematics/AR-317s.gif
>
> I'm not sure why you found adding a slightly filtered triangle  
> sounding wave useful when
> there's already a triangle wave output. My suggestion is if your  
> customers are not
> interested in a clean Sine output, use the panel real estate for  
> something more useful.
>
> --- In Doepfer_a100@yahoogroups.com, <yahoo@...> wrote:
> >
> > You find my answers written inline.
> >
> > Best wishes
> > Dieter Doepfer
> >
> > > -----Ursprüngliche Nachricht-----
> > > Von: Doepfer_a100@yahoogroups.com
> > > [mailto:Doepfer_a100@yahoogroups.com]Im Auftrag von laryn91
> > > Gesendet: Dienstag, 2. Dezember 2008 17:20
> > > An: Doepfer_a100@yahoogroups.com
> > > Betreff: [Doepfer_a100] Re: Sine wave discussion
> > >
> > >
> > > > And we will point out in the module information and user's  
> guide of
> > A-110
> > > > and A-111 that the sine outputs should be called more precisely
> > "sine-like".
> > >
> > > Dieter,
> > >
> > > It's probably just me, but where do you point that out for the  
> A-111?
> >
> > I wrote that "we will", not that "we did". That's the future tense  
> from what
> > I learned in scool - but I'm not a native speaker.
> >
> > > >If you want a perfect sine you need a VCO with a sine core.
> > >
> > > Instead of an impossible "perfect sine", how about just a sine  
> with no
> > *audible* overtones
> > > (<1% THD) like Arp, Moog, Aries, Polyfusion, EML,etc. used to  
> make? That
> > would now
> > > make the A-111 useful for additive synthesis and FM.
> > >
> > > All you need to do is copy their simple but superior
> > > triangle-to-sine converter design. ;-)
> >
> > Though I can't believe that they really reach <1% THD (but indeed  
> I never
> > measured it): do you (or anybody else in the group) know the  
> circuitry of
> > these converters. Are they made with diodes, OTAs or the JFET  
> circuit (these
> > are the three triangle-to-sine converter principles I know). I  
> don't have
> > the schematics of these VCOs.
> >
> > We would have offered a VCO with a more perfect sine in the past.  
> But it
> > took more than 12 years (the A-111 is available since spring 1996)  
> until
> > someone complained about the poor sine. I'll see what we can do.  
> Maybe we
> > offer a small tri-to-sine converter board for the A-111-1 that can  
> be used
> > instead of the simple diode converter.
> >
> > There was a similar discussion about 2 years ago (~ September  
> 2006) and Tim
> > Stinchcombe suggested an improved sine wave converter based on the  
> JFET
> > principle. We have built a prototype of this converter in 2006 but  
> the
> > discussion fell asleep very soon and it seemed that nobody was  
> interested
> > anymore. We could dig this design and offer it as an addendum to  
> the A-111-1
> > or equip all new A-111-1 with this board. The additional charges  
> would be in
> > the 15 Euro range (about 10 electronical parts mounted on a small  
> board).
> >
> > Best wishes
> > Dieter Doepfer
> >
>
>
> 



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