--- Dieter Doepfer < hardware@... > wrote:

> From: "Dieter Doepfer" < hardware@... >
> To: "Bakis Sirros" < synth_freak_2000@... >
> Subject: AW: 1 last chance to vote.
> Date: Thu, 22 Jan 2004 14:14:57 +0100
>
> > -----Urspr�ngliche Nachricht-----
> > Von: Bakis Sirros
> [mailto: synth_freak_2000@... ]
> > Gesendet: Donnerstag, 22. Januar 2004 10:37
> > An: dieter doepfer
> > Betreff: Fwd: 1 last chance to vote.
> >
> >
> >
> > --- Peter Baumann < peter.a.baumann@... > wrote:
> > > Date: Thu, 22 Jan 2004 10:15:10 +0100
> > > From: "Peter Baumann" < peter.a.baumann@... >
> > > To: synth_freak_2000@...
> > > Subject: Fwd: 1 last chance to
> vote.
> > >
> >
> > ---------------------------------
> > p {margin: 0px}
> > p {margin: 0px}
> > Bakis,
> >
> > while you are discussing new LFO modules I have an
> > additional comment. A general feature with LFOs
> that I
> > would really like to see is sync to MIDI clock. I
> have
> > had e-mail exchanges with Dieter Doepfer about
> this
> > subject, but since he thinks very "analog" he
> > immediately thought how difficult this would be
> with
> > analog components. Personally I do not care
> whether
> > the LFO waves would be generated digitally or
> analog
> > (for that matter in the future when every analog
> > module that has ever existed will have been
> re-build,
> > there will be no other way to move forward other
> than
> > digital components to really break new ground. I
> am
> > thinking about flexible envelope generators with
> many
> > break points that go far beyond the traditional
> ADSR
> > slopes for instance).
> >
> > In principal, Doepfer do have this LFO
> functionality
> > with th! e MCV24 already, however the resolution
> of
> > the slopes is not satisfactory. It should be
> fairly
> > simple for them to create a digital high
> resolution
> > LFO generator that would sync to MIDI clock or run
> > free and give a selection from beat sync to
> several
> > bar sync.
> >
> > Let me know what you and the group think.
> >
> > Peter
>
> The main problem is that you need a frequency (e.g.
> for the generation of a
> triangle LFO) that is a multiple of the frequency
> (e.g. MIDI clock) you have
> available. MIDI clock is 96 per measure or 24 for
> each quarter. If the
> triangle period has to be e.b. one quarter you have
> only 24 clocks (12 up +
> 12 down) to create a triangle e.g. with a DAC. The
> solution of the triangle
> is of course not sufficient. So you would need a
> higher frequency (i.e. a
> multiple) that is in sync with the MIDI clock. A-196
> user will say: OK -
> let's take a PLL.
>
> But it is not possible to create a higher frequency
> from a lower one without
> delay and attack "problems". In principle you need
> indeed a PLL (digital or
> analog, like the A-196). But in every case it will
> take several MIDI clocks
> (after a start) until the PLL has multiplied the
> frequency to the correct
> value (the PLL has to "lock"). In every case
> problems will occur in the
> first seconds after the start. I don't know a
> solution that would help and I
> think it is not possible on principle. Only if the
> (MIDI) clock is stable
> for a while a circuit (digital or analog PLL) is
> able to create a higher
> frequency.
>
> Please look at the PLL module information (A-196).
> Here you will find a
> small discussion of the PLL problems.
>
> We discuss at the moment a Synced LFO module
> (A-143-3) that internally
> likewise requires a master clock. The main problem
> in combination e.g. with
> MIDI clock is to obtain a (stable) frequency that is
> a multiple of the MIDI
> clock. Otherwise the resolution of linear waveforms
> (triangle, saw, sine)
> will be very poor. For rectangles this problem does
> not occur as one does
> not have to generate an analog slope.
>
> Best wishes
> Dieter Doepfer
>
>
> Best wishes
> Dieter Doepfer
>
>

=====
Bakis Siros
Parallel Worlds / Polariton
Athens-Greece
1 group owner
http://www.rubber.gr
http://www.ward12.com

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