## Re: vco octave switches

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• hello florian, many thanks for the great explanation :-) best wishes ingo ... to the ... poti. ... resistor ... tune ... of the
Message 1 of 12 , Jun 30, 2004
hello florian,

many thanks for the great explanation :-)

best wishes

ingo

--- In Doepfer_a100@yahoogroups.com, Florian Anwander
<Florian.Anwander@c...> wrote:
> Hi Ingo
>
> > is it a simple modification? soldering is not one
> > of my biggest strengths ;-)
> Yes, quite simple.
>
> From the center connector of the poti (=slider) a resistor leads
to the
> mixing point. The less the resistor the wider is the range of the
poti.
>
> As far as I remember the value is 1 Megaohm for the coarse.
> You do not have to remove the existing resistor. Simply add a
resistor
> with lower value parallel to the existing resistor.
>
> I added an 220kOhm resistor for the coarse tune. The value for fine
tune
> I do not remember at the moment.
>
>
>
>
>
>
> Further explanations:
>
>
> PP=Poti
> Ra=existing Resistor
> Rb=new Resistor
>
>
> Before:
>
> ----PP
> PP
> PP<----RaRaRa-----
> PP
> ----PP
>
>
> After:
>
> ----PP
> PP
> PP<--+-RaRaRa-+---
> PP | |
> ----PP +-RbRbRb-+
>
>
>
> R'a and R'b appear electrical like one Resistor R'eff.
>
>
> The new value can be determined by the following formula:
>
> R'eff = R'a * R'b / (R'a + R'b)
>
> Where is:
> R'a is the existing resistor
> R'b is the new add on resistor
> R'eff is the resulting value
>
>
>
> Example:
> Old resistor=1Megohm
> New resistor=1Megohm
>
> 1*1/(1+1) = 1/2 = 0,5
>
> So the resulting value is 0,5Megaohm. This would double the range
of the
> poti.
>
>
> Florian
• Blacet s have an input which will allow you to transpose up and down an octave, depending on if the input has a +1 volt (or above) signal -or- a -1 volt (or
Message 2 of 12 , Jul 1, 2004
Blacet's have an input which will allow you to transpose up and
down an octave, depending on if the input has a +1 volt (or
above) signal -or- a -1 volt (or below) signal at that input.

I think it has to do with the type of synthesis one does. Keyboard
performaers I think really prefer this octave switching feature,
while people who do the type of music which freely goes
inbtween the 1/2 step tend to prefer a full range pot.

- P

--- In Doepfer_a100@yahoogroups.com, "selfoscillate"
<synaptic_music@y...> wrote:
>
> hello list,
>
> after all that chat about vco's, there is one thing i
> really cannot understand.
>
> the doepfer vco's (a110 and a111) have those rotary octave
> switches and i find them very handy, because it keeps you
> from tuning the vco again if you only want to transpose
> the vco for two or three octaves in order to try something out.
> but doepfer seems to be the only manufacturer who cares
> (analogue systems, blacet) there is no such switch
> and i wonder why.
>
> am i the only one who finds these octave switches useful?
> or would you say that it is a feature which is not that important?
> i know that it is no "must-have" feature for me, but it is
> a "very nice to have" feature imho.
>
> best wishes
>
> ingo
• the blacet can transpose an octave downwards? shame on me, i didn t realize and therefore never tried that. thanks for the info, peter :-) best wishes ingo
Message 3 of 12 , Jul 1, 2004
the blacet can transpose an octave downwards?
shame on me, i didn't realize and therefore never
tried that. thanks for the info, peter :-)

best wishes

ingo

--- In Doepfer_a100@yahoogroups.com, "(i think you can figure that
out)" <peter@b...> wrote:
> Blacet's have an input which will allow you to transpose up and
> down an octave, depending on if the input has a +1 volt (or
> above) signal -or- a -1 volt (or below) signal at that input.
>
> I think it has to do with the type of synthesis one does. Keyboard
> performaers I think really prefer this octave switching feature,
> while people who do the type of music which freely goes
> inbtween the 1/2 step tend to prefer a full range pot.
>
> - P
>
>
> --- In Doepfer_a100@yahoogroups.com, "selfoscillate"
> <synaptic_music@y...> wrote:
> >
> > hello list,
> >
> > after all that chat about vco's, there is one thing i
> > really cannot understand.
> >
> > the doepfer vco's (a110 and a111) have those rotary octave
> > switches and i find them very handy, because it keeps you
> > from tuning the vco again if you only want to transpose
> > the vco for two or three octaves in order to try something out.
> > but doepfer seems to be the only manufacturer who cares