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.
Connecting the two ground posts may not work! The RCA ICs should be enough for grounding between the phono stage and the integrated amp. You can try it any way - let us know the result!
Jumper cables, yea, jumper cable.. I have some 2.0 fine mesh that aught to do it.. welding leads with screw clamps.. :-)
fuzztone's got it.. Just good ol copper # 20-16 and a couple of fork/spade crimpable terminal ends or eyelets and you're sittin' in tall cotton :-)
I keep a dozen alligator clip leads 12-24" long all the time.. Bread board work, kinda need it.. #22-18 and a few heavy leads #10. Good for trouble shooting noise issues too..
You've definitely created a ground loop. Everything should be to one outlet on the same line. Avoid different power lines at all cost. Ground problems are TRICKY. You might want to look into a ground block.
Very likely a ground loop complex topic why don’t you Google and read up on ground loops and then do a bunch of experiments to identify it and eliminate it also how are you driving mono block amplifiers with a phono stage and no volume control in between them seems to me you’re leaving something out of this
the hum is caused by using components on two different ground potentials you need to use all of the amps on the same outlet or you will have these sorts of problems.
Perhaps the most important consideration is not to create a grounding loop. In that regard every piece of equipment should be connected to a central point.
Sometimes it can be excessive hard when using RCA as the shield serves two purposes: the second side of the signal and a grounding path. With balanced or XLR one end of the shield can be disconnected if absolutely necessary when a groundling loop is created.
I have a similar humming/ buzzing from my speakers when I connect my Bluesound Node2i. as soon as I plug the power in the buzz starts.
when you say @speakermaster, connect to the same outlet are you referring to the same power lock?
would this be apply the same to all components? so I have turntable, phonostage and Bluesound Node2i Steamer with DAC built in.
could the issue be the Bluesound is two pole power lead (Double Insulated Product). My amp and Turntable have 3 way grounded power leads. Is there a conflict?
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.
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.
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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