[sdiy] Suitcase synth updates

[patchell]

Generally, if you want to add level control to one of the CV inputs, I use a 100K linear
pot.  Wiper goes to CV input of the VCO, one end of the pot to ground, and the other end of
the pot becomes the input.  With a 100K pot and the 100K input resistor, you will not
exactly get a linear response from the pot rotation...but, I have never noticed it.



charlie lamm wrote:

> Wow!  The ASM-1 VCO looks great.  Thanks for the suggestion.
>
> I have a few questions that maybe someone in this group can answer.
>
> a) I assume to add level control to the various modulation inputs I should
> put a voltage divider (potentiometer--linear I would guess?) in series
> with the 100K resistors.  To give me control of a modulation source, a la
> the front panel of an ARP Odyssey.
>
> b) Does anyone know of an already made PCB for a single ASM-1 VCO?  Core,
> modified, or otherwise.  I see a 4-banger here:
> http://hem.bredband.net/bersyn/VCO/VCOPCB_l.pdf
>
> But only need a single.  And of course the ASM-1 VCO's are part of a
> bigger synthesizer PCB.
>
> On Wed, 8 Jan 2003, patchell wrote:
>
> >     This is one case where it is truely a VCO (we are talking about the 3819 aren't
> > we?)...(what we commonly call VCO's are generally CCO's, ie current controlled
> > oscilators).  But to tell you the truth...this VCO (core) is not all that much simpler
> > that the "Asm1" type oscilator, if you were to strip off exponential circuit.  The
> > ASM1 oscilator consists of one opamp, one comparator, a FET, a couple of caps, and a
> > handfull of resistors (for just a sawtooth output).
> >
> > charlie lamm wrote:
> >
> > > I really like how simple the VCO is.
> > >
> > > Can anyone suggest a suitable temp-compensated 1v/octave convertor to
> > > "slap on" the front of this?  That would make it perfect for a project I
> > > am working on....
> > >
> > > On Tue, 7 Jan 2003, Electronium wrote:
> > >
> > > > Hello all,
> > > >
> > > > I've made quite a few updates to my suitcase synth project webpage:
> > > >
> > > > http://home.attbi.com/~michaeltbrown1/e_sdiy.html
> > > >
> > > > Any ideas/thoughts/comments/suggestions/criticisms would be greatly appreciated.
> > > >
> > > > Cheers!
> > > >
> > > > Mike Brown
> > > > mike at electronium.com
> > > >
> > > >
> >
> > --
> >  -Jim
> > ------------------------------------------------
> > * Visit:http://www.silcom.com/~patchell/
> > *-----------------------------------------------
> > *I'm sure glad Merry Christmas comes just once a year
> > * -Yogi Yorgensen
> > ------------------------------------------------
> >
> >

--
 -Jim
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* Visit:http://www.silcom.com/~patchell/
*-----------------------------------------------
*I'm sure glad Merry Christmas comes just once a year
* -Yogi Yorgensen
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