2. tech-talk
  3. 128479-46

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
4,422 posts
 
last_lemming OP  265 posts                                              02-20-2017 10:46am

What TT are you using? Cartridge?

I have a Dynavector 20x2L, and the cables are Cardas Clear Light. They have never given me trouble before. I don’ t know if this matters but the noise is coming from both speakers, but I assume if one cable was bad then that noise would affect both, but I really don’t know.


I will try swapping out cables tonight to see if that helps.

//

Did you try what I suggested, disconnect the TT phono cables from the phono preamp? You said the hum/buzz was independent of the volume control setting, so just turn down the volume control and listen if the hum/buzz is still there with the TT disconnected from the phono preamp.

If the hum/buzz is gone then there something between the TT and the phono preamp going on. IF the hum/buzz is gone then I would say the problem, issue, is not between the preamp and power amp.

If the Hum/buzz is still there then the next thing I would ask is how close is the Parasound JC3+ Phono preamp to the power amp?

Try moving the preamp as far away as possible from the power amp. Especially the power transformer of the power amp. Try turning off and unplugging the power cords of any other equipment near the preamp. Only have the preamp, power amp and TT plugged into the AC power.
ptss
1,964 posts
 
When did this problem arise?
last_lemming OP
638 posts
 
I will try removing the cables tonite. However the TT has no power and is not directly plugged into anything (VPI prime TT). 

The problem arose when I moved my TT setup to another room and switched to single ended output from the phono pre instead of my XLR cable I used previously. The speakers in this new system are super sensitive (101 db) and these noise noticeable. 
Post removed 
gs5556
1,233 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.
More to discover