From: Patent Tactics, George Brock-Nannestad
about 30 years ago I used to read Scandinavian HiFi magazines, and I remember
that there were special problems in Norway, because you could not get a
decent ground. The ground resistance would change from location to location
due to the rocky ground, which meant that even if one wire from the 10kV-240V
transformer were called zero and was grounded, it would not be the same
ground when the cable came to your house. The variation may be due to changes
in ground conductivity in dependence of humidity. If I remember correctly,
one solution was to have an insulating transformer (1:1), with a local ground
at a centre tap in the secondary, and to run your hi-fi from that.
Grounding problems may certainly influence the signals, and by removing the
headroom in one direction, they may cause overload and distortion.
I am sure things have not changed and there must be local HiFi people who can
> I have sometimes problems with "ground" hum from the power on my set-up.
> The problems are most often with my 78 rpm turnable playback system
> consisting of a Rek-O-Kut turnable, Pro-Ject pre-amp, Packburn 323A and
> Rek-O-Kut re equalizer and de-hisser. It is not quite permanent.
> BUT; when it sometimes appear it seems like it also make the music signals
> sound distorted, especially at the end of the records.
> May such hum also have something to say for the music signals, like
> distortion, maybe, or will it just cause that "famous" "ground" problems
> sound from the loudspeakers?
> All the best