Cgs synth

Well, that was quick! The 10K resistor at the 1 and 2 pins of the
4011 wasn't connected to 0v solidly. Now the Sub Osc rocks hard!

For the uninitiated, even one channel makes for a very big sound!
No exaggeration is possible here - Ken's design is killer! This has
plenty of sequencer applications, too, but my grandson has to get to
bed.

Thanks again Ken!

Chub -relaxed and mightily impressed

--- In cgs_synth@yahoogroups.com, "charlesosthelder"
<osthelder@n...> wrote:

> Ack! Virtual ground! Have I forgotten everything?
>
> I'd already gotten my answer earlier, though, as the B channel

works

> well now. The A channel isn't so cooperative. There's nothing

past

> the second opamp stage. The diode tested okay and there's a

feeble

> (just over the noise) signal present at the 4011 pins 1 and 2, but
> the output is simply high at pin three. Voltages are good at all
> the devices, diodes are oriented correctly...I gotta figure this
> out. At first, I figured the 4011 was just dead, but no such luck.
>
> I've got a pot for the x2 output of both A and B. If I turn the

pot

> full counter-clockwise, the B channel drops out. It would seem I
> need extra resistance above ground on those pots. Everything else
> on the B channel is fine - actually an excellent sound! I can't
> wait to get both channels working, this is a very versatile module.
>
> Any ideas will be considered!
>
> Chub
>
> --- In cgs_synth@yahoogroups.com, sasami@h... wrote:
> >
> > >If I use switches instead of pots for the divider outputs, will

I

> need
> > >to add a 47K resistor to ground for each output to the mixer?
> I've
> > >finished this pcb but have no output except the channel B x2.
> This is
> > >sent straight to a pot and the mixer.
> >
> > No need to add anything to ground. Reason 1 - it doesn't require

a

> load.
> > Reason 2 - it's getting one anyway when it connects to the

summing

> node of
> > the mixer (Virtual ground).
> >
> > Ken
> >
>

_____________________________________________________________________

> __
> > Ken Stone sasami@h... or sasami@c...
> > Modular Synth PCBs for sale
> <http://www.blaze.net.au/~sasami/synth/>
> > Australian Miniature Horses & Ponies
> <http://www.blaze.net.au/~sasami/>