Need some smart electrical people to chime in...

Jetmaker737

So I was wiping a smudge off of my Yamaha amp with the back of a finger when I noticed what felt like a slight mechanical buzz in the metal case. What's weird is I could only feel it when moving the finger along the metal, not when holding it still. After messing around a bit I discovered this same buzz on all three components, Amp, CD player, and tuner. This is my setup:




My fear was that my new amp is messed up since I could disconnect IC's from a component and stop the buzz at that component. I did a lot of swapping around of cords plugged/unplugged, IC's in/out, etc. This is my plug arrangement below. Amp cord is in one receptacle, plug strip with CD, tuner, and SBT in the other. (nevermind the wad of wires on the right. Those are not connected)




Results of all the swapping is:

1. The amp will buzz when powered on (and so will everything else). It will not buzz powered off (except see #2 below)
2. The CD player will buzz when plugged in even when powered off and even when the amp is disconnected from the CD or the amp is unplugged from the wall. The CD player will cause all the other components to buzz too. Disconnecting IC's or unplugging the CD player stops it.
3. One other thing... when everything has been powered off for awhile there is no buzz anywhere. It takes a minute for the buzz to return after powering up the amp or the CD player.
4. Note that there is no audible hum from components or speakers.

So I'm figuring this is maybe a problem with the grounding of the house electrical supply? But it seems there's some kind of capacitance contribution from the components. Any helpful suggestions appreciated. Also, is there risk of damage in running the system like this?

mhardy6647

It is AC leakage onto the chassis of the component(s).
It may be within allowable limits.

FestYboy

Break out the dvom and start probing!

pitdogg2

FestYboy wrote: »

Break out the dvom and start probing!

This but carefully^^^^^ very carefully

txcoastal1

FestYboy wrote: »

Break out the dvom and start probing!

You can measure to the electrical ground to see if it's volts or millivolts between chassis' and ground

I often feel these buzzes when working around ceiling grid....still creeps me out

Jetmaker737

I have an old analog VOM. So I would probe the chassis with one lead... where would I find the electrical ground?

txcoastal1

The ground plug in on your outlet or power strip

delkal

If your outlet is full take out the screw holding the faceplate off. And carefully stick the tip of the probe in. The screw thread is grounded to the junction box. You can also take the faceplate off and touch anywhere on the metal box for ground. But again be careful.

A ground on another outlet will work too.

Make sure your meter is set for AC volts and make sure you are only touching the insulated probe handles.

txcoastal1

delkal wrote: »

If your outlet is full take out the screw holding the faceplate off. And carefully stick the tip of the probe in. The screw thread is grounded to the junction box. You can also take the faceplate off and touch anywhere on the metal box for ground. But again be careful.

A ground on another outlet will work too.

Make sure your meter is set for AC volts and make sure you are only touching the insulated probe handles.

Many residential boxes are plastic

Jetmaker737

Well I took my old analog meter and probed from the chassis to one of the ground receptacles in the plug strip. Got no reading. Smallest scale available was 2.5 VAC.

delkal

txcoastal1 wrote: »

delkal wrote: »

If your outlet is full take out the screw holding the faceplate off. And carefully stick the tip of the probe in. The screw thread is grounded to the junction box. You can also take the faceplate off and touch anywhere on the metal box for ground. But again be careful.

A ground on another outlet will work too.

Make sure your meter is set for AC volts and make sure you are only touching the insulated probe handles.

Many residential boxes are plastic

Even then the hole for the faceplate screw is grounded. Also the "wings" where you put the 2 screws to mount the receptacle into the box are grounded as well.

Jetmaker737 wrote: »

Well I took my old analog meter and probed from the chassis to one of the ground receptacles in the plug strip. Got no reading. Smallest scale available was 2.5 VAC.

Did you check to see if you are getting 110v from the right side plug (I think that one is hot) to ground. Make sure you have your meter set to 200volts and make sure it is on AC (not DC). Be even more careful this time.

How old is your house? Are you sure the plug is properly grounded?

What happens when you disconnect everything from your surge protector and plug everything into a cheap power strip?

FestYboy

Be especially careful using an analog VOM, they draw current to operate and can toast sensitive electronics if placed incorrectly. Chassis voltage checks will not be a problem, I wouldn't recommend going inside with it though.

tonyb

txcoastal1 wrote: »

The ground plug in on your outlet or power strip

This would be the easiest place to start, and probably the most likely culprit. You have some nice gear there, a power conditioner should be in your future and get rid of that power strip.

F1nut

get rid of that power strip.

That was my first thought.

tonyb

What was the second ?

mhardy6647

tonyb wrote: »

What was the second ?

Don't rush him

EndersShadow

Well I was going to suggest @lightman1 give some advice... but you asked for "SMART" electrical people .

This also wholly rules me out as I'm dumb as a box of rock about electricity beyond the fact that a fork in a socket works 50 times better than any coffee to wake me up.

So its been my goto for years (which is why my hair is spiked )

mhardy6647

EndersShadow wrote: »

Well I was going to suggest @lightman1 give some advice... but you asked for "SMART" electrical people .

This also wholly rules me out as I'm dumb as a box of rock about electricity beyond the fact that a fork in a socket works 50 times better than any coffee to wake me up.

So its been my goto for years (which is why my hair is spiked )

ouch.

Back, kinda sorta, on topic, here are some tidbits on AC leakage that might be helpful and/or of interest to the OP. Or not.
http://audiokarma.org/forums/index.php?threads/feeling-a-tingle-of-electricity-on-the-front-of-the-receiver.689797/
http://audiokarma.org/forums/index.php?threads/what-is-the-purpose-of-this-resistor.761888/

EDIT: couple more


https://electronics.stackexchange.com/questions/60556/grounding-and-why-charge-leakage-occurs
http://www.avhub.com.au/features/hi-fi/im-shocked-why-am-i-getting-a-tingle-394771

delkal

Get a plug in receptacle ground tester. They are cheap and it will instantly show if your receptacle is hooked up and grounded correctly.



https://amazon.com/Power-Gear-Receptacle-Indications-50542/dp/B002LZTKIA

mhardy6647

Not a bad thing to have around -- but I doubt (FWIW) there's anything hooked up "wrong".

Jetmaker737

F1nut wrote: »

get rid of that power strip.

That was my first thought.

Probably a good suggestion but the power strip is not the culprit. When the CD and Amp are plugged directly into the wall the condition still exists. It's gotta be the house ground. The house is over 100 years old though much has been upgraded.

kharp1

Jetmaker737 wrote: »

F1nut wrote: »

get rid of that power strip.

That was my first thought.

Probably a good suggestion but the power strip is not the culprit. When the CD and Amp are plugged directly into the wall the condition still exists. It's gotta be the house ground. The house is over 100 years old though much has been upgraded.

Love how the OP asks for "smart electrical people" yet can confirm that the power strip is not the culprit. Did you remove the power strip completely? I'm no expert by any means, but, I am an industrial electrician (work with robots mainly) and it's the little things like this that are overlooked that can trip you up. The issue could very easily be with the power strip and back feeding in to the system. The power strip may be fine (though I'm in agreement with others and would remove it permanently) and the problem lie elsewhere, but, until you've tried you won't know. Don't assume anything. Bad components plugged in to the circuit can cause problems, and, power strips are know to be problematic.

lightman1

Just don't run your fingers across it and you'll never have a problem.

mhardy6647

lightman1 wrote: »

Just don't run your fingers across it and you'll never have a problem.

Another proud graduate of the Henny Youngman School of Medicine.

Jetmaker737

kharp1 wrote: »

Love how the OP asks for "smart electrical people" yet can confirm that the power strip is not the culprit. Did you remove the power strip completely? I'm no expert by any means, but, I am an industrial electrician (work with robots mainly) and it's the little things like this that are overlooked that can trip you up. The issue could very easily be with the power strip and back feeding in to the system. The power strip may be fine (though I'm in agreement with others and would remove it permanently) and the problem lie elsewhere, but, until you've tried you won't know. Don't assume anything. Bad components plugged in to the circuit can cause problems, and, power strips are know to be problematic.

Yes, I could confirm that the power strip was not the culprit because I had completely removed it and plugged the CD player and amp directly into the wall, as stated.

kharp1

Time to get Russ to make a house call.

txcoastal1

kharp1 wrote: »

Time to get Russ to make a house call.

Jet didn't mention anything about issues with the bushes

Jetmaker737

I do have a rat and/or squirrel problem. Can he help with that?

delkal

Jetmaker737 wrote: »

F1nut wrote: »

get rid of that power strip.

That was my first thought.

Probably a good suggestion but the power strip is not the culprit. When the CD and Amp are plugged directly into the wall the condition still exists. It's gotta be the house ground. The house is over 100 years old though much has been upgraded.

If your house is that old you definitely need that receptacle tester. You should check every plug in your house. I doubt they upgraded all of them.

mhardy6647

kharp1 wrote: »

Time to get Russ to make a house call.

artist's conception thereof.

tonyb

Jetmaker737 wrote: »

kharp1 wrote: »

Love how the OP asks for "smart electrical people" yet can confirm that the power strip is not the culprit. Did you remove the power strip completely? I'm no expert by any means, but, I am an industrial electrician (work with robots mainly) and it's the little things like this that are overlooked that can trip you up. The issue could very easily be with the power strip and back feeding in to the system. The power strip may be fine (though I'm in agreement with others and would remove it permanently) and the problem lie elsewhere, but, until you've tried you won't know. Don't assume anything. Bad components plugged in to the circuit can cause problems, and, power strips are know to be problematic.

Yes, I could confirm that the power strip was not the culprit because I had completely removed it and plugged the CD player and amp directly into the wall, as stated.

Then the easiest place to start, and cheapest, is to change out that wall receptacle. Go to home depot and get a hospital grade one at the very least.