Wiardgroup

Actually I disassembled the patch and now that I think about it, I may have had an lfo going into the control in.  I'll experiment and report back if there is a problem.

Bryan

Bryan Cornell
Reference Librarian
Recorded Sound Reference Center
Motion Picture, Broadcasting and Recorded Sound Division
Library of Congress, Washington, DC 20540-4698
Phone:  (202) 707-7833
Fax:       (202) 707-8464
email:     bcor@loc.gov
Usual disclaimers apply.
>>> grichter@asapnet.net 12/03/05 5:17 PM >>>
Not sure what is up with that.

The basic idea is simple. If you use an evelope to sweep a filter,
as the oscillator pitch changes, the extent of envelope sweep remains constant.
So high notes have fewer harmonics than low notes.
By adding the keyboard voltage, you move the filter with the oscillator,
and produce roughly the same amount of harmonics for each note across the keyboard.

The Mini-Moog has switches for this. Patching keyboard CV to "Key In" is the same as
having both switches down on a Mini-Moog.

Possible problems are a bi-polar keyboard voltage (+/-) or envelope not connected
to filter "Control In".

--- In wiardgroup@yahoogroups.com, "Bryan E Cornell" <bcor@l...> wrote:
>
> I'm having a bit of a problem (I think) with the key input of my Boogie filter.  I assumed 
that you are meant to plug a keyboard cv in here so that the filter will follow the keyboard.  
Is this correct?  When I tried this, all my low notes were very quiet and the high notes were 
loud, resonant, and buzzy. When I unplugged the keyboard cv from the key input on the 
Boogie Filter the tone and volume were much more even across the range of the keyboard.  
My patch was simple: keyboard CV to mult so it could be fed simultaneously to the 
oscillator and the filter.  The rest of the patch was the gate out of the keyboard to an EG 
and to the VCA into which I had plugged the output of the filter.
> 
> I feel like I'm missing something fundamental.
> 
> Bryan
> 
> Bryan Cornell
> Reference Librarian
> Recorded Sound Reference Center
> Motion Picture, Broadcasting and Recorded Sound Division
> Library of Congress, Washington, DC 20540-4698
> Phone:  (202) 707-7833
> Fax:       (202) 707-8464
> email:     bcor@l...
> Usual disclaimers apply.
>








 
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That should have read bi-polar control voltage.
A the negative half of a bi-polar LFO is at -5 volt which will move the filter down 5 
octaves.
The 1 or 2 octave keyboard control voltage will not be able to compensate.

--- In wiardgroup@yahoogroups.com, "Bryan E Cornell" <bcor@l...> wrote:
>
> Actually I disassembled the patch and now that I think about it, I may have had an lfo 
going into the control in.  I'll experiment and report back if there is a problem.
> 
> Bryan
> 
> Bryan Cornell
> Reference Librarian
> Recorded Sound Reference Center
> Motion Picture, Broadcasting and Recorded Sound Division
> Library of Congress, Washington, DC 20540-4698
> Phone:  (202) 707-7833
> Fax:       (202) 707-8464
> email:     bcor@l...
> Usual disclaimers apply.
> >>> grichter@a... 12/03/05 5:17 PM >>>
> Not sure what is up with that.
> 
> The basic idea is simple. If you use an evelope to sweep a filter,
> as the oscillator pitch changes, the extent of envelope sweep remains constant.
> So high notes have fewer harmonics than low notes.
> By adding the keyboard voltage, you move the filter with the oscillator,
> and produce roughly the same amount of harmonics for each note across the keyboard.
> 
> The Mini-Moog has switches for this. Patching keyboard CV to "Key In" is the same as
> having both switches down on a Mini-Moog.
> 
> Possible problems are a bi-polar keyboard voltage (+/-) or envelope not connected
> to filter "Control In".
> 
> --- In wiardgroup@yahoogroups.com, "Bryan E Cornell" <bcor@l...> wrote:
> >
> > I'm having a bit of a problem (I think) with the key input of my Boogie filter.  I 
assumed 
> that you are meant to plug a keyboard cv in here so that the filter will follow the 
keyboard.  
> Is this correct?  When I tried this, all my low notes were very quiet and the high notes 
were 
> loud, resonant, and buzzy. When I unplugged the keyboard cv from the key input on the 
> Boogie Filter the tone and volume were much more even across the range of the 
keyboard.  

> My patch was simple: keyboard CV to mult so it could be fed simultaneously to the 
> oscillator and the filter.  The rest of the patch was the gate out of the keyboard to an EG 
> and to the VCA into which I had plugged the output of the filter.
> > 
> > I feel like I'm missing something fundamental.
> > 
> > Bryan
> > 
> > Bryan Cornell
> > Reference Librarian
> > Recorded Sound Reference Center
> > Motion Picture, Broadcasting and Recorded Sound Division
> > Library of Congress, Washington, DC 20540-4698
> > Phone:  (202) 707-7833
> > Fax:       (202) 707-8464
> > email:     bcor@l...
> > Usual disclaimers apply.
> >
> 
> 
> 
> 
> 
> 
> 
> 
>  
> Yahoo! Groups Links
>