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Can't tell,if my house is properly grounded

Hey guys, I have a low level hi/low buzz that is coming through my speakers, not dependent on the integrated tube amps volume. It is amplified when I turn on my Parasound JC3+ Phono preamp, but only slightly. I have the power cords going to the same outlet. I tried running their power through my Furman Elite Power conditioner but that changed nothing. I ran an independent ground wire and checked all the components in various configurations to no avail. I disconnected all the tv cable to make sure it wasn't coming from there and that solved nothing either. I turned off everything in the house I could' no change. I checked my ground outside at the rod and it is all solidly connected, however the depth of the rod is unknown.

any other thoughts before I call out an electrician?
last_lemming
jea48
2,944 posts
 



Possible Problems:

Noise in the system, a hum or buzz:

o The answer is to ground the motor and system properly. A line filter that floats the grounds will not allow proper grounding of the phono system, the phono system must be grounded!!!!!! Phono is not like CD and if this is your first table or your return to vinyl after a decade or so you must remember that phono amplification can be 1000 times higher than CD or streaming so any noise that gets into the system will be amplified much, much more. Kill the noise with proper grounding and your system will sound much better.
http://media.wix.com/ugd/5e0564_3b9b738ded8246ab8e7fe7ce2ce0c3aa.pdf

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Did you run a ground wire from the TT ground terminal/lug to the phono preamp ground terminal lug? The wire connects the TT arm as well as, I would imagine, the spindle bearing / aluminum platter to the signal ground of the phono preamp. (Signal ground, not to be confused with the earth ground.)

How about the TT AC synchronous motor. Is there any ground wire that connects from the motor to the TT?

Tonight when you try the tests I suggested make sure the TT AC motor is unplugged from the AC power.


gs5556
769 posts
 
I second Erik's suggestion of having a tech look at it. There is the possibility that a safety cap in the receptacle is leaking ac, especially the one from N to ground. If the fuse blew with that extension cord, it's possible you reversed polarity and ac went to ground through the bad cap, especially if there is an earth line choke between the safety caps. 

It's a long shot but it could explain why you're getting a groundloop even when plugged into the same outlet as the amplifier.
oscar44
114 posts
 
Am a bit confused about what has changed. Seems like hum came when you changed room...and the gear change was a switch to single ended rather than balanced cables from phono stage, and new speakers? Speakers and amp seem to check out ok, correct? But the phono cable introduces the noise? Can you go back to balanced cables to see if that matters? If not, can you adjust the gain level on the phono to see if that has any effect?
last_lemming OP
407 posts
 
Ok, I did everything everybody said, and there is no change buzz is still there.

to answer a question from above I switched the room the phono pre was in and went from single ended to xlr because the tube amp doesn’t have xlr. I have had the same issue with an old Conrad Johnson amp, where it would buzz as well.

Could the tube amp be the culprit? Bad tube?

i also noted that the buzz/hum is older on different wall outlets. 
last_lemming OP
407 posts
 
I second Erik's suggestion of having a tech look at it. There is the possibility that a safety cap in the receptacle is leaking ac, especially the one from N to ground. If the fuse blew with that extension cord, it's possible you reversed polarity and ac went to ground through the bad cap, especially if there is an earth line choke between the safety caps.

To be clear it made the noise prior to me trying to use the cheater plug that flipped the polarity. 
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