I concur, a professional electrician is definitely your next step.
It’s a detail, but since your landlord is required to pay for the electrician’s bill, you might want to give them a heads up if you haven't already.
Did I just cook my preamp?
I have a Simaudio Moon 110LP phone preamp amplifying a Dynavector 20X2L cartridge on a VPI Classic. It feeds in to an Outlaw Audio RR2160 amp which drives Magnepan LRS speakers.
I recently moved and two months in I realized my speaker placement wasn’t quite right, so today I reorganized my listening room. This involved unplugging some power cables but I kept most of the interconnects in place. I did have to disconnect the phone stage from the amplifier.
After getting things back into place, I listened to some music using coaxial input before reconnecting the interconnects of the phono stage. When I tried to, I actually got some electric current that burned my hand slightly. This came from the back of the amplifier. I made sure everything was unplugged and tried again - this time a spark and smoke from the interconnect making contact to the back of the amplifier.
I’m so confused why this would happen, but eventually I did get everything connected. Now the output from the phono stage is just a bump every 1 second. It doesn’t amplify the signal from the TT.
My amplifier has a built in phono stage and using this I was able to verify that the turntable is still producing a signal. The built in phono stage sounds terrible, however, as thin and flat as paper. It is music, however.
When I connect the phono stage to the power, the blue light on the front illuminates for a moment and then goes dark.
Incredibly, when I was unplugging the phono preamp, I actually got some current from simply touching the exterior of the box. Something is seriously wrong and dangerous with my setup, and this box was grounded to the turntable with a ground cable, which was connected to the outlet with a three prong cable with ground.
Has anyone experienced anything like this before? I will email Simaudio and see if they’ll repair it. I’m also taking recommendations for replacements. I liked the 110LP and maybe will just replace with the 110LPV2.
- ...
- 107 posts total
@obarrett said:
I agree. You should call the building manager or Landlord. They more than likely have their own Electrical Contractor they use for the electrical work in their buildings. You shouldn’t have to pay anything. Some of the electrical is unsafe. FYI, I would remove the 2 to 6 outlet "converters" for the day Electrician is scheduled to come out. . As for the measurements in your above post.
The Hot / neutral polarity wiring is correct. Hot (small slot) to ground 120Vac is correct. Neutral to ground 0.36Vac looks good. If it were me, I would buy one, or two if needed, descent plug strips and plug all your audio equipment into it/them plugged into this wall outlet. At least until you can get an electrician to troubleshoot and fix the electrical wiring problems. / / / /
This outlet has the Hot and neutral reversed, mis wired. Therefore LG: 120Vac Is wrong, not safe. I would not use this outlet to feed your audio system equipment. To be honest, I can’t see how you can... Imo, outlet 1 ground is screwed up causing the 120Vac between outlet "1" and outlet "2" equipment grounds. The wire feeding the ground contact on the outlet is actually the branch circuit HOT ungrounded conductor. It’s not a ground conductor. Good chance the branch circuit is only a 2-wire circuit for Outlet "1". If you have a drop cord to plug into another grounded outlet, that tested correctly for Hot / neutral wiring polarity, you could confirm if it is the cause of the 120Vac measurement. . / / / / / . I was about to send this post when I noticed your latest post. Looking for info on the VPI Classic TT I found this YouTube video. Note the steel plate. Apparently, the tone arm tower base is bolted to the steel grounded plate. ??? I don’t have any proof it is though. Fact, you measured continuity between the IEC inlet connector EGC and the tone arm ground lug/ ground wire. . More reading material for you. Here is another possible example for the ground contact on the wall outlet, the TT has been plugged into,... to be Hot 120V. Assuming everything was fine with the audio system until you decided you wanted to tweak the speaker placements. IF by chance you unplugged the TT power cord from the wall outlet. (Or for any other reason the outlet could have been disturbed using it for other things plugged into it.) Assuming the duplex receptacle was not grounded. (Therein two-wire branch circuit wiring. Old worn out 2 wire outlet was changed out to new 3 wire grounding outlet by a former tenant. No wire is connected to the EGC ground terminal Outlet opening is 1 gang flush rough-in steel switch box. Hot and neutral are revered on the outlet. Therein the Hot conductor is connected to the neutral side terminal on the outlet. Neutral conductor is connected to the hot contact terminal screw side. On a regular grounding type duplex receptacle, the EGC contact terminal screw is on the same side as the neutral contact terminal screw. It is possible the duplex receptacle was not tightly fastened to the wall recessed rough-in box. Odds are it is not. It is possible if the outlet was disturbed by, Unplugging the power cord and or plugging the cord into the outlet, the HOT neutral contact terminal side and the EGC ground terminal is now contacting the side of the steel 1 gang box. The side of the steel box is electrically energizing the ground contacts of the duplex receptacle. This one you could safely check. Remove the outlet plastic plate. Once removed look at the neutral contact side of the outlet. Does it look like it is against the side of the steel box? If yes, do you a plastic tea or milk container you can cut out a rectangular piece of the plastic? Slide it between the outlet and the steel box. You can cut a rectangular piece for the other as well. Slightly tighten the two 6/32 screws that fasten the outlet to the box if needed. Replace wall outlet cover. Check the ground contact to see if it is still hot. No need to reply to either post, unless want to.. If you have any further questions, you can always PM me using the Audiogon messaging system. Jim |
Hey Jim, the reason why I didn’t have an issue before is that I wasn’t using outlet 2 before. Everything that needed a ground was in outlet 1. Only after I moved things around could I access outlet 2. thanks again to you. Thanks also to you Devin. If I actually have a reverse polarity bootleg ground I will be so angry. You guys saved me more than money. |
Reverse polarity OR bootleg ground alone won't manifest until something else goes wrong. It's the combination of the two that is potentially lethal, because any grounded (3-prong cord) piece of equipment you plug into such an outlet sees its chassis, cover (and anyone who touches it) energized. Please do post your electrician's findings. Curious now! |
@obarrett said:
FYI, outlet 2 has an earthed ground. Well, the mm measurement says so. A plug in circuit tester would say so. A Bolted Hot to the EGC ground fault might tell a different story. Using outlet 1 you didn’t/don’t have a ground. The ground contact on the outlet is HOT 120Vac with reference to an earthed ground. All the metal enclosures of the audio equipment were HOT 120Vac referenced to ground. Even audio equipment that didn’t use an earthed EGC. The TT power cord is a 3 wire cord. When plugged into outlet 1 it fed the branch circuit HOT 120Vac to the TT IEC inlet connector EGC prong. That in turn fed HOT 120Vac to metal parts of the TT and to the tone arm ground, *(by the way the tone arm was HOT with reference to an earthed ground), to >> the phono preamp enclosure, which made all the RCA jacks outer ground shells HOT 120Vac that contaminated all the other metal enclosures through the interconnect cables signal ground conductor. Why you never got an electrical shock or had problems with your audio system equipment? There was not an earthed ground introduced into the equation. So, for the same reason a bird perched on a high voltage power Line doesn’t get shocked. Now the Squirrel is a different story. He will jump onto High voltage power Line and run down the Line without a care in the world. It’s his dismount from the high voltage power Line to the top of the metal earth grounded pole transformer is his fatal problem. If only he had jumped instead of stepped.
FYI, I am pretty sure the heat radiator shown in the video is earthed grounded. Had you been able to touch it with one hand, (in the summer months), and touched any of the HOT 120Vac metal enclosures of the audio equipment with the other hand there is a chance you would have been electrocuted. Therein dead. DO NOT use outlet 1, until it is wired correctly by an electrician. . I suggest you try another test. Plug an OEM power cord into outlet 1. Insert one of the test lead probes into the IEC female ground contact. Turn mm to V and touch the other test lead probe to a bared (unpainted) metal place on the heat radiator. You can also use the LoZ setting on the mm as well. Post back the measurement. . |
- 107 posts total