I haven't tried connecting the ground wires, of the lines in, directly to the ground/neutral bar because the lines in are all too short (the reason, I assume, the electrician did it the way he did).

I have a ground wire from the ground post of my amp, directly connected to the ground/neutral bar in the panel.

That buzzing door bell transformer shares power with the line, I think, for my audio room. Can this transformer cause dc on the ac line? This is absolutely new to me, these concepts.

thanks,

John