1 - A filter is frequency sensitive where a wave shaper is not. The sine converter will
perfectly track and always maintain perfect phase alignment with the other VCO waves. No
parameters in the converter need to be tracked or changed over the full VCO range.

A filter unfortunately requires changing its center frequency to *exactly* match the VCO.
The filter also introduces phase and amplitude variations. I have never been able to
successfully do this because all my filters can't track the VCO.

2 - All my self-oscillating filter sines change amplitude as the frequency changes. This
makes them useless for oscillator applications. Plus mine don't track anywhere near as
good a the A-111.

3 - Did I miss a rule somewhere that I am not allowed to use *any* additive synthesis
methods with Doepfer analog Can't I simply take 4 sine oscillators, VCA's, sequencer,
wave shapers, envelope generators, etc. and craft a cool sound by carefully summing
analog components

Why ever prefer analog at all over digital To my ears analog sounds better because it's an
infinitely continuous signal without all the undesired artifacts from discrete PCM
conversion.

--- In Doepfer_a100@yahoogroups.com , Monroe Eskew <monroe.eskew@...> wrote:
>
> I'm not trying to be rude; I just don't see an upgrade of the Doepfer
> oscillators to be necessary or worth it. I'm not against sine waves;
> they're great. But there are a few things I don't understand. I'm
> just curious...
>
> 1. Why doesn't a filter count as a "nonlinear wave shaper"
> 2. Why isn't using self oscillation on a filter such as the A121
> sufficient for your purposes This produces a natural sine wave,
> right The A121 has excellent keyboard tracking IMHO.
> 3. If additive synthesis is the game, why prefer analog over digital
>
> Cheers,
> Monroe
>
> On Dec 2, 2008, at 5:10 PM, laryn91 wrote:
>
> > No, it's NOT a filter at all. It a non-linear wave shaper.
> >
> > What I don't get is why are some so passionately *against* sine
> > waves I must violating
> > some unwritten analog commandment here but can't figure out what it
> > is. After all, most
> > vintage modular VCOs had clean sines - what's wrong with that
> >
> > All I asked was which VCO generated undistorted sines and got lots
> > of rude replies and
> > insults. My favorite is the very angry guy below who is pushing I
> > get banned from this
> > group! Yikes...
> >
> > --- In Doepfer_a100@yahoogroups.com , Monroe Eskew <monroe.eskew@>
> > wrote:
> > >
> > > I don't get it... If the upgrade just filters the triangle in a
> > better
> > > way, then an LPF should do the same work. If your real concern is
> > > additive synthesis, then perhaps you should get the digital RS370,
> > or
> > > a computer program. Or perhaps use self-oscillation on a filter that
> > > has good tracking
> > >
> > >
> > > On Dec 2, 2008, at 4:13 PM, laryn91 wrote:
> > >
> > > > I wouldn't send mine back to Germany either.
> > > >
> > > > But I would buy upgrade boards and wire them in for all my Doepfer
> > > > oscillators (110, 111,
> > > > 145, etc.)
> > > >
> > > > --- In Doepfer_a100@yahoogroups.com , Bakis Sirros
> > > > <synth_freak_2000@> wrote:
> > > > >
> > > > > ok, i could do that poll.
> > > > > Dieter, any more specific details for the poll
> > > > >
> > > > > btw, in case there was a modified Sine circuit for the A111
> > > > produced, i would be
> > > > probably not bothered to send my 8 A111's back to doepfer to be
> > > > 'converted' with the new
> > > > sine design... it would be much trouble and time lost, for me...
> > > > >
> > > > >
> > > > > Bakis Sirros - Parallel Worlds / Interconnected / Memory Geist
> > > > > 1 group owner
> > > > > www. parallel - worlds - music. com
> > > > > www. myspace. com/ parallelworldsmusic
> > > > > www. myspace. com/ interconnectedmusic
> > > > > www. myspace. com/ memorygeist
> > > > > www. DiN. org. uk
> > > > > www. musicamaximamagnetica. com
> > > > > www. shimarecords. co. uk
> > > > > www. rubberrecords. gr
> > > > > Athens - Greece
> > > > >
> > > > > --- On Wed, 12/3/08, york luethje <ybl@> wrote:
> > > > >
> > > > > From: york luethje <ybl@>
> > > > > Subject: Re: 1 Re: Sine wave discussion - Poll
> > > > suggestion
> > > > > To: Doepfer_a100@yahoogroups.com
> > > > > Date: Wednesday, December 3, 2008, 12:52 AM
> > > > >
> > > > >
> > > > >
> > > > >
> > > > >
> > > > >
> > > > >
> > > > >
> > > > > Couldn't we just have a poll My suspicion is that the practical
> > > > value of very good
> > > > analogue sine waves will be high for only some. As Dieter
> > posted, an
> > > > earlier discussion
> > > > then fizzled out and didn't result in any product modifications.
> > > > Maybe the discussion has
> > > > shown there there is indeed a lot of (commercially tangible)
> > > > interest in an oscillator with a
> > > > very good sine output. On the other hand, maybe the interest is
> > more
> > > > intellectual and
> > > > doesn't incite people to actually part with their money and buy
> > the
> > > > new design. A poll
> > > > could give us at least an indication. I suggest something like
> > this
> > > > >
> > > > > "Do you want Doepfer to modify the sine-converter in the A-111
> > to
> > > > produce a purer
> > > > sine wave The cost increase would be in the 5% - 10% range."
> > > > >
> > > > > York
> > > > >
> > > > > ____________ _________ _________ __
> > > > > From: Monroe Eskew <monroe.eskew@ gmail.com>
> > > > > To: Doepfer_a100@ yahoogroups. com
> > > > > Sent: Tuesday, December 2, 2008 3:39:52 PM
> > > > > Subject: Re: 1 Re: Sine wave discussion
> > > > >
> > > > > Couldn't we just use a standard LPF for this
> > > > >
> > > > > On Dec 2, 2008, at 11:46 AM, James Husted wrote:
> > > > >
> > > > > > 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.leinerme dia.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: 1 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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