[sdiy] Curious powersupply/power distribution problem

[Seb Francis]

Isolate the I/O with a small transformer?

Karl Ekdahl wrote:
> Hi list
>
> I have a problem, i'm making a stompbox that's being fed from a regular 9V transformer, internally i'm dividing it up to +-4.5V because i need a split powersupply. Now this is working perfectly, until someone plugs in one of those transformers that feed several stomps. At that point my ground and the other circuits grounds are 4.5V apart, problematically enough it won't work for me to (just) use opamps that can run from non-polar voltages.
>
> Now what i need to do is to make my circuit work with audio signals that aren't referenced to my ground, but in fact my -4.5V. I tried biasing each signal with +4.5V but that didn't work, to the problem belongs that i need to be able to use both AC and DC signals. 
>
> help!!!!!
>
> Karl
>
>
>       __________________________________________________________
> Låna pengar utan säkerhet. Jämför vilkor online hos Kelkoo.
> http://www.kelkoo.se/c-100390123-lan-utan-sakerhet.html?partnerId=96915014
>
> _______________________________________________
> Synth-diy mailing list
> Synth-diy at dropmix.xs4all.nl
> http://dropmix.xs4all.nl/mailman/listinfo/synth-diy
>
>
>