My completly-HUM Free LM4780 setup

[lykkedk]

Hi.

I would just contribute, with (after long time stroggling) - Well at least in my setup... a completly HUM Free setup / connections !

After trying a lot of setup's including PWR-stargnd / linein-stargnd... and all those trick's, i finally found that the HUM, was comming from my twistedpair RCA inputs.

Well, i tried using shielded cable, and Humming suddently stopped, now it was only very low. When disconnecting one- end of the shield at the RCA side, all humming is gone now I think it might be due to a little gnd-loop ind the shield of the cable.

Well take a look at my picture.

Jesper.