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.
The deductible is too high, the v2 of the 110LP new is only $600 and renter’s insurance would give only the actual/market value of the used one I have, which is considerably less than $600. it’s not really a problem, I’m just grateful to be alive. If I had touched the tone arm of my turntable at the same time as I was touching my CD player, I would’ve died, even if both were turned off |
https://youtube.com/shorts/t1jazBAT3M4?si=uweJOKoK0xRxrYDH In your video, when you measured for voltage from the receptacle ground contact to the heat radiator the test probe connection to the receptacle ground contact was poor. The 120Vac reading was not a solid contact connection. You should have used the OEM power cord ground. Insert the mm probe into the center ground contact. That also frees up your hand and you can focus your eyes on the probe connection to the radiator valve and the meter. . WARNING: I hope you saved the plastic outlet cover plate you removed from the receptacle. When you remove the 2 to 6 outlet extender everything metal you see is HOT 120Vac to anything grounded. Don’t put your body between them. ** EDIT: On second thought. Don’t remove this one. Just leave it be. . Also in case you haven’t thought of it. You are going to have to move the speakers and audio equipment out of area the electrician will be working. Take some pictures first of the equipment where it normally is sitting. Just in case he asks. The Electrician needs a minimum of 3ft working space in front of the wall outlets. The more the better. A happy Electrician is a productive Electrician.
Did you watch this video? Reverse Polarity Bootleg Ground Testing . |
Old rubber cloth covered insulated copper wire. This is why I advise a non electrician do not pull an outlet out of a wall or ceiling box in a really old apartment building, or an old house. The building Landlord has mess. An expensive mess. And more than likely the whole building’s wiring is in the same shape. Just a guess the electrician didn’t find a bootleg ground jumper wire on the neutral contact side terminal screw to equipment ground terminal screw on the Hot / neutral reversed polarity outlet. (outlet 1.) I doubt he found a jumper on any of the outlets. The rubber/cloth insulation deteriorated over the years causing the bared copper wire to contact the wire support bracket. There was a 50/50 chance whether the Hot wire or the neutral wire faulted to the steel bracket / box. It’s kind of amazing that both didn’t fault to the box. Dead short. Neutral fault to the box it’s an earth grounded box. Hot fault to box, a HOT 120Vac to ground box. The odds are good that there are other outlets in the apartment the electrical wiring is in the same condition Did the electrician say what type of branch circuit wiring it is? It could be BX steel armored cable. It probably comes through a hole in the back of the box and the clamp holds it in place. In the third picture I thing I can see the cut end of the armor. I see brick on walls in your photos. Just a guess the building is constructed of brick. ??? Did the electrician say what wiring method he will use to rewire the apartment? The only thing I can see is install surface mount Wiremold. Wiremold steel raceway. 500 / 700 series Start on page 47. I’m really curious, find out who manufactured the electrical panel that feeds your apartment. . |
