Cgs synth

Hi All,

New to this group, live in Holland and working on MOTM/Oakley/CGS
system.

Got a Steiner VCF PCB coming my way and got two questions (cross posting
to SynthPanels group):

1. What are my best options for mounting it on a Schaeffer panel, I
figure there's more than one way (Stooge bracks/pot bracks?) can someone
maybe make a breakdown of the best/less good/worst options?

2. Concerning the gain stage, is it advisable to ad an overall gain pot
or will a resistor/link do? I like tsomneevich design in the SynthPanels
files section, would this be a matter of adding an extra hole, under the
hp in for example?

Krimo





[Non-text portions of this message have been removed]

Krimo wrote:

>Hi All,
>
>New to this group, live in Holland and working on MOTM/Oakley/CGS
>system.
>
>Got a Steiner VCF PCB coming my way and got two questions (cross posting
>to SynthPanels group):
>
>1. What are my best options for mounting it on a Schaeffer panel, I
>figure there's more than one way (Stooge bracks/pot bracks?) can someone
>maybe make a breakdown of the best/less good/worst options?
>
>

I use a Stooge 3-pot short bracket, which is long enough for Ken's PC
boards. The Steiner VCF board is narrow, so you even have room to mount
two of them side by side on one bracket. The only boards I mount by pot
brackets are Oakleys that are specifically designed for this type of
mounting.

>
>2. Concerning the gain stage, is it advisable to ad an overall gain pot
>or will a resistor/link do? I like tsomneevich design in the SynthPanels
>files section, would this be a matter of adding an extra hole, under the
>hp in for example?
>
>
>

I second John Loffink's suggestion here:

>Output "level" jumper/resistor: I put 180K in the level position, in
>addition to the 47K already in the op amp feedback path, or just put 220K
>total in the 47K position. This gave the maximum resonant oscillation
>amplitude without clipping and brought the normal non-oscillating output to
>a better level.
>
>
>
>

While many CGS modules provide for a variable output level, my view is
that it is better to have a fixed output level. Attenuation should
occur on inputs. Save a panel pot and put in a fixed resistor.

-Richard Brewster

I used a single 390K fixed resistor. Now you have tons of gain; then
attenuate the gain at the input stage.

BTW, I am adding VC attenuators via "Mike Irwin" VCA's to the audio
inputs....I will put the details up on my site when I am done (I am
almost done now...LP and BP are already working) and put a link
here....so far experiments are encouraging.

--CL