Author Topic: A/C line noise  (Read 6063 times)

Offline papabearjew

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A/C line noise
« on: May 14, 2013, 10:57:42 PM »
Hi all,
I seem to be picking up some sort of noise that I suspect is coming through the A/C line. It is not constant. Sometimes I'll notice it when the clothes dryer cycles or when I operate my electric lift chair (recliner).  Sometimes I'll hear a popping sound through the speakers for no apparent reason. I do listen to music a lot...pretty much all day long. I have a Carver C-5 preamp feeding a Phase Linear 400 amp...both modded by Vintage HiFi. Any suggestions for an affordable solution?
Thanks,
Brad

Offline Slim-Shaddy

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Re: A/C line noise
« Reply #1 on: May 14, 2013, 11:39:18 PM »
2 prong to 3 prong converter
I am confident that an SL-1200 is capable of outperforming turntables of much higher expense with minor modification.

Offline papabearjew

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Re: A/C line noise
« Reply #2 on: May 15, 2013, 12:01:44 AM »
@Slim-Shaddy,
I know the adapters you are referring to but don't understand the suggested application.  Can you please elaborate.
 I am really pushing to get this resolved before June 18th if at all possible.
Any help is greatly appreciated. Tom pointed me in the direction of posting this on the forum.
Thanks,
Brad

Offline Rockman Rock

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Re: A/C line noise
« Reply #3 on: May 15, 2013, 12:22:38 AM »
Dimmers and motors including reclining chairs can send noise into power line and EMI/RFI into the air. If on the same AC circuit I don't think there is any escape except for filtering or running separate circuit. I've seen simple plug in filters and filter powerstrips but you'd have to make sure they have enough capacity to pass the current required by your amp.

For EMI/RFI, you need tin foil hats. I have a recliner here that if plugged into my separate audio AC circuit it will cause problems with digital playing but not analog. Could be the non-shielded Cat5 inside wall picking something up. Maybe it sends DC spikes into the power line, I dunno. All is well if the chair is plugged into different circuit.
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Offline Slim-Shaddy

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Re: A/C line noise
« Reply #4 on: May 15, 2013, 12:26:07 AM »
The 3 to 2 prong this was something I used when I was in a band and the guitarist was getting shocked. Not sure if it would help, but it's a very cheap solution if it works.
I am confident that an SL-1200 is capable of outperforming turntables of much higher expense with minor modification.

Offline Rockman Rock

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Re: A/C line noise
« Reply #5 on: May 15, 2013, 12:32:30 AM »
Just to add, whenever I or a friend has a problem with AC wiring I bring my little AC wall tester with. Plugging it into the outlets will quickly tell me if hot/neutral are reversed and show ground integrity. I picked this up at one of the home supply stores.

I have lifted grounds with the three/two prong adapters for testing but hate to leave them lifted. If something shorts it is bestif it has a path to follow.

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Offline Rockman Rock

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Re: A/C line noise
« Reply #6 on: May 15, 2013, 12:43:26 AM »
Funny story, kind of. Our first house after renting a couple years. An old post war bungalow. Dear wife tells me she gets a bad shock if she is doing dishes and touches cabinets. I was like no way. They were old Geneva painted steel cabinets with a stainless sink. I wet my hand, put it on sink and grab cabinet, yee ha!  Old knob and tube wiring, metal box, no ground wire, hot shorted to box off light switch, chrome metal wall plate covering switch touching Geneva metal cabinets. Only ground was you touching sink and cabinets. I believed whatever she told me after that.
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Offline schwarcw

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Re: A/C line noise
« Reply #7 on: May 15, 2013, 10:23:42 PM »
Rich,

We're going to start calling you Sparky LOL!
Carl

Offline Rockman Rock

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Re: A/C line noise
« Reply #8 on: May 15, 2013, 11:28:49 PM »
I have this habit of testing for bad grounds by touching stuff. My first ModWright 9.0SE pre amp had a bad hum. I touch pre amp and amp, noise goes away. They failed to grind powder coat away before attaching ground lug in the pre amp. I don't encourage anyone checking for bad grounds that way, especially if you have a pacemaker. >:D
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Offline OCCD

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Re: A/C line noise
« Reply #9 on: May 16, 2013, 12:13:20 AM »
The 3 to 2 prong this was something I used when I was in a band and the guitarist was getting shocked. Not sure if it would help, but it's a very cheap solution if it works.


The Guitarist was getting shocked... sparky...    >:D :o :o :o There can be only one sparky here.  I remember that day...   Ed, is the amp OK????...
« Last Edit: May 16, 2013, 12:16:07 AM by OCCD »
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