Thanks Ken, All the correct voltages are going to the correct pins (-15v to pin 7 +15v to pin 14) I may have put the 3900 that burned up in backwards ?
I checked all the component values and diode orientations this morning.I still have to go through and check continuity throughout the circuit.
I've noticed both sections outputs exhibit the same behavior which is a negative offset around -6v with nothing feeding the inputs.I checked pin 9 in the stepped section and if i feed a slow ramp and clock the sample input i get a varying voltage between -6 and -13v but always stays in that range.
I checked all the component values and diode orientations this morning.I still have to go through and check continuity throughout the circuit.
I've noticed both sections outputs exhibit the same behavior which is a negative offset around -6v with nothing feeding the inputs.I checked pin 9 in the stepped section and if i feed a slow ramp and clock the sample input i get a varying voltage between -6 and -13v but always stays in that range.
--- In cgs_synth@yahoogroups.com, sasami@... wrote:
>
> Also check you don't have your power rails swapped about.
> If you have used CA3401 instead of a lm3900, and it's seeing 30V it will go
> pop too, as they are only good for 15V rails, unlike the lm3900.
>
>
> >Hey guys, I just put together the SSG and it's not working so i tried to
> switch out the lm3900's after giving the board some continuity testing and
> looking over the board briefly, i still need to do a lot more
> troubleshooting but what i wanted to ask about was this,
> >when i switched the lm3900's out it froze my system up as if there was a
> short in the power supply.I did some tests to see but couldn't find a short
> anywhere so i put the old ones back in and system powered back on fine so i
> switched them out with brand new ones i had and it cooked them within
> seconds of powering up.
> >
> >Like i said i still have a bunch of leg work to do to figure out why it's
> not working but am confused that some of the lm3900's would create what
> appears to be a short and the others seem to have no effect ?
> >
> >Thanks, Tony
> >
> >
> >
> >------------------------------------
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> _______________________________________________________________________
> Ken Stone sasami@... otherunicorn@...
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>