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Ground Wire

The tonearm cable is plugged into RCA input of the phono stage. The tonearm ground wire is connected to the ground post of the same phono stage. The first RCA L/R outputs of the phono stage are connected to a pair of mono blocks. There is no hum I could hear coming from the speakers connected to them. The second L/R outputs of phono stage are connected to the line input of the integrated amplifier that drives a second pair of speakers. That's where the hum is quite audible. That integrated amplifier also has the ground post. I wonder if I could get rid of the hum by connecting the phonostage's ground post with the ground post of the integrated amplifier. What kind of wire should be used to connect two ground posts of two different preamplifiers? The units are at least 8 feet apart. 
esputnix
fiesta75
1,378 posts
 
Are you using a ground block or power conditioner? By outlet, he means the same wall outlet and if possible the same plug in that wall outlet. I know I'm not @speakermaster, but trying to help. This does apply to ALL components. It does not matter if it's 3 prong or 2 prong plug. All 2 prong plugs nowadays should have one lug larger than the other, so it can only be plugged in one way.
lewm
13,019 posts
 
What fiesta just wrote.If you're using a fancy power block of some kind, it is at least remotely possible that in the power block, each plug or set of plugs is isolated from all the others.  If the block is poorly designed, I can at least imagine that might promote ground loops.
Also, "using XLRs" is a waste of money and effort, if the associated components are not internally balanced circuits.  If they ARE balanced, then use XLRs, by all means.  This issue comes up all the time in this forum.
fiesta75
1,378 posts
 
For ground loops you should ONLY use a high grade power block. This is the last resort. You are absolutely correct about XLR's. You should always put all components into one outlet. Even some outlet boxes can have 2 sources.
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