SergeModular

Hi!

I'm not really sure about the VCA content of the quadrature
oscillator [QUO] because I haven't had to fix any. I know it has a
real VCO in it and it must have the two VCAs on the outputs. The
[QUO] has its own dedicated PCB, which is not stacked. It is the
same type of oscillator needed in a frequency shifter. In fact, it
is one of the three boards used in the frequency shifter.

It uses the traditional matched transistors and tempco in the expo
converter rather than the "oven" used in the [NTO] and [PCO]. The
[NTO] is a stacked module. It contains the basic oscillator board as
used in the [PCO] and another board containing the waveshaper and
other features unique to the [NTO].

There is a really cool triangle quadrature oscillator design in
Juregen Haible's frequency shifter project.

check it out:
http://www.oldcrows.net/~jhaible/tonline_stuff/hj_fs.html

I hope this helps everyone's curiosity. It's about all I know about
the [QUO]. I hope I haven't revealed any trade secrets!

-Nick Librecht


--- In SergeModular@yahoogroups.com, "phix_it <phix_it@y...>"
<phix_it@y...> wrote:

> Thanks Nick,
> I stand corrected ( though If you would be kind enough to
> share a little MORE info that what it's NOT I'm sure many, like
> myself would appreciate it.) Looking at the description in the
> catalog I see the two outputs have voltage controlled gain. This
> would imply the need for 4 VCA's (2 for the actual oscillator

circuit

> and one each for the two output gain controls)
> Having said that a more informed guess would be that the

Quadrature

> Oscillator uses the Quad VCA PCB with a piggyback control board.
>
> BUT !!! as before I stand to be corrected. :)
>
> Cheers....Dean.
>
>
> --- In SergeModular@yahoogroups.com, "keeperofthewogglebug
> <keeperofthewogglebug@y...>" <keeperofthewogglebug@y...> wrote:
>
> > The Quadrature Oscillator is NOT "a Variable Q VCF set to
> permanently
> > self oscillate." It has its own unique PCB.
> >
>
> > -Nick Liebrecht