Fw: [sdiy] I have found that SSM2210 transistor arrays give better performance in my latest oscillator design.

[scottnoanh at peoplepc.com]

"Using  Rossum  compensation, the VCO tracks really well until one gets to
between 60 to 15360 Hz, but it goes goes quite sharp from 60 to 30 Hz:  29
cents =-(.  Tuning that out leaves the oscillator going sharp starting at
around 960 Hz or so."

Confusing sentence, sorry, long day.  Meant to say:

Using  Rossum  compensation, the VCO tracks really well  between 60 to 15360
Hz, but it goes goes quite sharp from 60 to 30 Hz:  29 cents.  Tuning that
out leaves the oscillator going sharp starting at around 960 Hz or so.

Anybody had to trim high end sharpness out of a VCO?  Or is there a way to
compensate for the low end (the 30 to 60 Hz).

Thanks,
Scott



----- Original Message -----
From: <scottnoanh at peoplepc.com>
To: <synth-diy at dropmix.xs4all.nl>
Sent: Saturday, June 24, 2006 10:34 PM
Subject: Re: [sdiy] I have found that SSM2210 transistor arrays give better
performance in my latest oscillator design.


> OK, here's something I've never seen mention of: tuning out sharpness at
the
> high end of a VCO.
>
> Using  Rossum  compensation, the VCO tracks really well until one gets to
> between 60 to 15360 Hz, but it goes goes quite sharp from 60 to 30 Hz:  29
> cents =-(.  Tuning that out leaves the oscillator going sharp starting at
> around 960 Hz or so.
>
> Has anybody had an expo converter go sharp at the top end?  If so, how
does
> one compensate for that?
>
> Thanks,
> Scott
>
>
> ----- Original Message -----
> From: "René Schmitz" <uzs159 at uni-bonn.de>
> To: "Paul Perry" <pfperry at melbpc.org.au>
> Cc: <synth-diy at dropmix.xs4all.nl>
> Sent: Saturday, June 24, 2006 8:01 PM
> Subject: Re: [sdiy] I have found that SSM2210 transistor arrays give
better
> performance in my latest oscillator design.
>
>
> > Hi Paul and all,
> >
> > Paul Perry wrote:
> > > I'm not an EE, but I'm suprised there isn't some clever
> > > way to (exactly or approximately) cancel out the Rbe.
> > > Anyone? I'm sure EDN would publish it...
> >
> > Well there is: Rossum compensation. (and variants...)
> >
> > Cheers,
> >   René
> >
> > --
> > uzs159 at uni-bonn.de
> > http://www.uni-bonn.de/~uzs159
> >
> >
>