Cgs synth

Ken,
thanks for your suggestion, the power supply took care of the hum!!

The low pass still didn't work, but I traced the problem to a bad pad
on the pcb. This PCB had a few bad pads on it, but the others I
noticed while I was putting it together. All of the other PCB's Ive
gotten have been fine. Something must have gone wrong in the
manufacutre of this one.
Anyway, problems are all solved. This is a GREAT sounding filter!!

thanks so much
Scott

Describe "bad pad". I've not seen any bad pads on any of my boards so far,
so I'd like to know what you mean.

Ken

Im talking about where the holes are drilled through the board, and
there is the metal pad where you put the solder.

there were three on this board. One was missing. One fell off as
soon as I started to solder it. Then the third I just found today.

The one today was for the resistor at the L/P input. The one that was
missing was for one of the three caps that are in the middle of the
board, and the other was a diode I believe.. I didn't pay attention to
where that one was.

I got the vco working. This one was my fault!! bad solder on one of
the bridges that goes across the pcb (where I installed a jumper
across two points.. dono what its really called)

but now the pulse out doesn't work and the shape doesn't do anything..
tho sound does come out of it.
I guess I'll start searching around the associated IC's and see what I
can find.

Scott

I think the technical term for the 'pad' is a *land*.

-Richard Brewster

http://www.pugix.com

c10h14no2i wrote:

>
>there were three on this board. One was missing. One fell off as
>soon as I started to solder it. Then the third I just found today.

This is usually because the pad got too hot when soldering. THe copper foil
is only glued on, and if you apply too much heat, they let go and can
fall/break off. Another thing that causes this is too much mechanical
pressure applied by the component itself - usually limited to larger
electrolytics which move when subject to some sort of physical shock,
lifting the pad off the PCB.

Ken

>
>The one today was for the resistor at the L/P input. The one that was
>missing was for one of the three caps that are in the middle of the
>board, and the other was a diode I believe.. I didn't pay attention to
>where that one was.
>
>I got the vco working. This one was my fault!! bad solder on one of
>the bridges that goes across the pcb (where I installed a jumper
>across two points.. dono what its really called)
>
>but now the pulse out doesn't work and the shape doesn't do anything..
>tho sound does come out of it.
>I guess I'll start searching around the associated IC's and see what I
>can find.
>
>Scott
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>The CGS Modular Synth home page: http://www.cgs.synth.net/
>
>Yahoo! Groups Links
>
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_______________________________________________________________________
Ken Stone sasami@... or sasami@...
Modular Synth PCBs for sale <http://www.blaze.net.au/~sasami/synth/>
Australian Miniature Horses & Ponies <http://www.blaze.net.au/~sasami/>