[sdiy] Hi All

[harrybissell]

Hi Ray

I built some VCA using the LM13700 very similar to what you have done.
I found that with the VCA cut completely off, the offset of the output buffer
causes a little 'thump' which I could not entirely trim out.  I suspect that if
you used an opamp buffer, it would be better.

I see there is no AC coupling, is that a problem with the offset. I see some
in your scope photos, but that could be the scope setup as well.

Now I use the CA3280 for a VCA. It is dead quiet... and soon dead unavailable :^(

H^) harry

Ray Wilson wrote:

> I suggest you breadboard half of the circuit (one VCA) and see if you like
> it. They're not that big (3" x 4") and you get two VCAs on a board so they
> might be useful in a poly modular. But "ideal" I just don't know :-).
>
> Cheers
>
> Ray
>
> ----- Original Message -----
> From: "Cole Groff" <chonald at gmail.com>
> To: "Ray Wilson" <raywilson at comcast.net>
> Sent: Friday, October 28, 2005 8:37 PM
> Subject: Re: [sdiy] Hi All
>
> I'm very interested!
>
> Would these VCAs be ideal for a polyphonic modular?
>
> Cole
>
> On 10/28/05, Ray Wilson <raywilson at comcast.net> wrote:
> > Some people say gettnig LM13700s is hard but they are still in full
> > production so I don't find it hard at all.
> >
> > Ray
> >
> >
> > ----- Original Message -----
> > From: "Cole Groff" <chonald at gmail.com>
> > To: "Ray Wilson" <raywilson at comcast.net>
> > Sent: Friday, October 28, 2005 8:05 PM
> > Subject: Re: [sdiy] Hi All
> >
> >
> > That sounds great.
> >
> > Is it hard getting any of the components?
> >
> > Cole
> >
> > On 10/28/05, Ray Wilson <raywilson at comcast.net> wrote:
> > > I plan to check them on +/-15V and publish any necessary changes.
> > >
> > > Cheers
> > >
> > > Ray
> > >
> > >
> > > ----- Original Message -----
> > > From: "Cole Groff" <chonald at gmail.com>
> > > To: "Ray Wilson" <raywilson at comcast.net>
> > > Sent: Friday, October 28, 2005 2:54 PM
> > > Subject: Re: [sdiy] Hi All
> > >
> > >
> > > Hrmm, is there anyway these would work with a +/- 15V power supply?
> > >
> > > I would buy some if they did.
> > >
> > > Cole
> > >
> > > On 10/28/05, Ray Wilson <raywilson at comcast.net> wrote:
> > > > Hi Everyone.
> > > >
> > > > A shameful promotion...   VCA PC Boards for $12.00 each.
> > > >
> > > > http://www.musicfromouterspace.com/analogsynth/DLLVCA001/DLLVCA001.html
> > > >
> > > > Cheers All
> > > >
> > > > Ray
> > > >
> > >
> >
> >