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Cgs synth

Index last updated: 2026-04-28 23:16 UTC

Message

Re: Smoke

2012-11-18 by fuyuhiko

Hi Ove.
Having removed both ICs and replaced those to new ones, it now works properly! Thank you very much.

One thing I wondered was on the schematic, there is no connections between 0V and ground, however, as it didn't work I connected it and seems fine.
Is there any circuit which mustn't have that connection??

Anyway thank you very much.


--- In cgs_synth@yahoogroups.com, Ove Ridé <nitro2k01@...> wrote:
>
> On 18 November 2012 10:16, fuyuhiko <hiko_goldenballs@...> wrote:
> > Hi there.
> > This is not a question for the CGS circuits but is for an ADSR envelope
> > I've been making.This is the schematics.
> >
> > [http://yusynth.net/Modular/Commun/ADSR/ADSR-V2-sch-thumb.gif%5d
> > <http://yusynth.net/Modular/Commun/ADSR/ADSR-V2-sch.gif>
> > Even though I've succeeded to make it on solderless breadboard, I now
> > suffer from smoke on the both 10Rs of the power supply. As soon as I
> > connect the power it happens.To be honest when I finished soldering
> > first time it worked but in an odd way, then I realised that I hadn't
> > connected -15V to the pin 11 of the TL074 and connected +15V to pin 5. (
> > very careless mistakes) This time there was not any smoke but since I
> > connected again.
> > I've checked all connections but no idea of how to make it work since
> > I've made the same power circuit four times.
> > Does anyone suspect any particular parts? Or should I solder it from
> > scratch again?
> > Sorry for the question that is not for the CGS.
> > Kind Regards
>
> Obviously, you have a short somewhere which makes current conduct from
> +15V to -15V. The first sanity test question is, are you sure you
> haven't swapped the positive and negative power supplies, now or at
> any point during the build? This could potentially immediately destroy
> all of the chips. The discrete transistors are also vulnerable, but
> they have big resistors in series in all directions and wouldn't be
> able to cause this kind of major failure.
>
> My advice would be to remove the 555 and the TL074 and first try
> powering up the board without them, then adding them one by one and
> see when the fault happens. If the fault happens without either of the
> chips present, the problem is different. Either just a dumb short
> somewhere, or way too small resistor values somewhere causing what is
> effectively a short, or reverse polarity of the polarized capacitors,
> C1 and C2, which would cause them to conduct a DC current. If the last
> option is the cause of your error, those will likely start emitting
> smoke as well at some point.
>
> In case like these, it's useful to have a bench power supply with
> current limiting, so you can detect a fault like this without having
> to burn components.
>
> --
> /Ove
>
> Blog: <http://blog.gg8.se/>
>
> "Here is Evergreen City. Evergreen�¿ is the color of green forever."
>

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