Doepfer

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
>