Grounding My Equipment


Can I run ground wires from my amp and cd player to the phono ground post on my preamp (to which I've already attached the ground wire from my phono) without creating problems or risking damage to my equipment? I get a hum in my phono stage when my cd player is on (but no hum when cd player off). All equipment is plugged into a Panamax 1000 (could this be the problem -- I don't believe the Panamax plugs are "isolated" like the plugs on other ac blocks?). Thanks for any thoughts/comments.
vtl

Showing 2 responses by sean

All of your equipment shares a common ground through the interconnects. Adding another wire from component to component probably won't do much for you other than create more of a mess. The only way that this might help was if all of your equipment used a floating chassis ground, which i highly doubt. This is the best way to build gear, so obviously, most "hi-end" manufacturers DON'T use that approach : )

Have you tried verifying if your outlets are correctly wired for proper polarity ? Have you verified that your equipment is oriented for lowest ( or "most similar" ) voltage readings on the chassis ? Other than that, make sure that your power cords and interconnects are well away from each other. If it is hard to arrange them so that they are spaced apart, go to Menard's / Handy Andy / Builder's Square, etc... and pick up some foam pipe insulation. You can run cables both sets of cables through their own foam insulation tube and this will keep them at least an inch or two away from each other. The foam acts as a spacer between between the cables and minimizes crosstalk between them. Don't know if this will help though, so try spacing them out by hand as best possible first before investing in the foam pipe insulation. Sean
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PS... Foam pipe insulation costs about $1 for 16 feet of it.
Aball: By "floating" grounds, i meant that the chassis would be "Earth grounded" but not tied to "signal ground". This provides what is known as a "Faraday shield" or "Faraday cage" and reduces the noise floor of the component. At the same time, safety is NOT compromised so long as one does not "lift" the ground at the plug / outlet. Most designs DO tie the chassis to signal ground, resulting in the potential for increased noise.

As to the results that you obtained by plugging the CD into the preamp, you had a difference in ground potential in your system. This is commonly called a "ground loop". By doing what you did, you tied the grounds together and negated any difference in ground. While this is a good thing, it opens up the potential to "more directly" transmit "digital hash" from the CD player directly into the gain stages of the system. You might want to try doing what i suggested above, as it could result in a small improvement without the potential for ( as much ) degradation. Sean
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