That clarifies everything. I'm not too scared of it, i've done a little bit of electrical investigation on cars and a little on homes but I just like being very clear when I do stuff with it!
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?
any other thoughts before I call out an electrician?
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- 42 posts total
GOOD NEWS!!! So I found a proper cheater plug and tried putting it on the tube amp only - buzz completely gone whether the phono pre was on or off. So it appears the amp was to blame and the phono preamp just amplified the problem. So now, hopefully, when my new Decware integrated tube amp comes in it wont exhibit this buzz/hum, if it does at least I know its not the AC line. I want to thank everyone who spent their time an energy helping me out! I learned a bunch and tracked down my problem. |
last_lemming OP 277 posts 02-21-2017 5:47pm The voltage measurements look great. Neutral to ground AC voltage of 50 millivolts is ok. With that said though IF there is an internal problem with the preamp and the neutral conductor is bleeding off somehow to the equipment ground conductor would a 50mv difference of potential, voltage, cause the hum you are hearing? Per NEC code the safety equipment ground and service entrance neutral conductor is intentionally bonded, connected, together at the main electrical service panel and not at point there after. If a difference of potential is present, (50mv), and a closed circuit exists, will current travel through the circuit? Yes, imo. Someone like Al, ( almarg ), could answer that question. Hopefully maybe Al is following this thread and will chime in. Curious what scale on the multimeter did you use when you checked the neutral to equipment ground voltage? The lower the scale the more accurate the reading. // How about the other test? With the preamp plugged into the AC outlet but powered off, not in standby if it has a standby feature, do you get hum/buzz through the amp/speakers? I believe if the preamp has AC line filtering it is done near the IEC inlet connector ahead of the main power on/off switch. I am not 100% sure of that though. Check to see if you get the hum with the main power switch turned off on the preamp. . |
GOOD NEWS!!!The cheater plug on the amp did break the ground loop circuit, but that does not prove the amp is at fault. It could still be the preamp causing the problem. So now, hopefully, when my new Decware integrated tube amp comes in it wont exhibit this buzz/hum, if it does at least I know its not the AC line. Time will tell. Good luck, Jim |
- 42 posts total