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dbowker
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My experience with Mysterious Hummmmm

OK- this is a little related to AlexO's post about the Hydra 8, but mostly just about how weird electricity can be, and how difficult it is to ever completely isolate your audio system from the rest of your house. This a longish post but I think will be instructive if you stay with me.

So here's my setup, which I wrote about before. I have a dedicated outlet that incorporates the PS Audio Soloist In-Wall Power Conditioner. My amp goes right into this outlet via an upgraded power cord (Harmonic Technology Pro AC-11). I don't think the Solist does a whole lot in the way of actually regeneration or anything, but it's very well made, has spike and surge protection, is UL listed and does have some minor noise cleaning. It's rated to a full, unrestricted 20amp output. When I had it, and the dedicated line, put in it was truly like an overall system upgrade. To me, like replacing all wires with better ICs and speaker cables. I heard stuff I had never heard before whether it was my digital end or analogue. It all sounded much more detailed and open with no attendant brightness and dead silent backgrounds.

OK- so that's all good, right, and I never have to think about what's happening with the rest of the house electrically again! Wrong!

About two months ago I started hearing this very noticeable HUM coming form my Krell KAV400i integrated amp at random times of the day or night. I mean noticeable from my listening chair 8 feet away- not just with ear up to the amp! Now I know the KAV has this huge toroidal transformer so obviously something was getting into the electrical system, and that thing was doing it's job to fix it I guess, but it was annoying and worrying at the same time. Plus I was like, WTF? I thought it was isolated? What could be getting IN to a line not a part of the rest of the house?

So I had my electrician back for another unrelated job and he points out that, although my circuit is isolated in the sense that nothing other than my audio system is using it's juice, the GROUND still is connected to the same central ground as everything in the house! What?! Doh! And further more, he says short of putting two more 8 foot copper ground bars buried in my yard just for said audio system, there is no way to truly take the circuit out of the loop. And by the way, everything in the house including pipes, vents and whatever else is ALL attached to this grounding system!

Hmmmm. That sucks...and it makes me question just how much you can isolate power, no matter how expensive your re generator is, 'cause it's still going to be grounded to that whole complicated mess. And I definitely don't want to think about what it'd be like if you lived in an apartment or dorm!

So now I'm trying to rack my brain as to what suddenly changed- of course I think it has to be our heating unit. Two months ago is when we started using it a lot, and the hum was not constant so maybe it was something to do with that. It wasn't--- and the only way I was able to start to pin it down was have the electrician turn off each breaker in the house, one at a time with me on the phone at my amp, until the amp went silent again. So, in the end it was two steam humidifiers upstairs that were the culprits. They were worst when set to LOW, which I take to mean the resistance between HIGH and LOW sends out a bunch of spurious noise into the electrical system. Simple, but difficult to find and not exactly obvious. Since then a tech at Krell said to me it's not the first time he's heard of humifiers casuing problems with their amps humming.

Luckily, it wasn't something more complicated or necessary to the household, and now when I want to really sit down for some listening it's a simple thing to make sure they are both off... Anyway- the process by which I was able to solve this was very instructive to me and hopefully might help someone else here as well. Happy listening.

bobedaone
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Re: My experience with Mysterious Hummmmm


Quote:
And I definitely don't want to think about what it'd be like if you lived in an apartment or dorm!

No, sir, you do not. I installed all new outlets (HG for the audio) and use a power conditioner, but I know it's still compromised.

On the plus side, I live on the ground and my floors are concrete. However, I live above the hot water heater and washer/dryer. It's give-and-take.

Elk
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Re: My experience with Mysterious Hummmmm

Electricity is indeed weird, fascinating stuff.

Congrats on finding the source of the problem.

KBK
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Re: My experience with Mysterious Hummmmm


Quote:
Electricity is indeed weird, fascinating stuff.

Congrats on finding the source of the problem.

The interesting point..is that Ben Franklin got it wrong.

He had a coin toss to get it right (joke), ie 50-50 chance. He called one post the positive terminal and the other the negative.

Now, many or most electrical textbooks are done his way, with regards to the direction of flow as an electrical function.

Then there is the second textbook, identical as the first..but with the electrical flow directions reversed.

This is because Ben Franklin got it exactly wrong and the flow is in reverse, and the energy flows out of the ground. That textbook is called the 'Electron Flow Version' of the given electrical scholastic text. Some say it makes no difference in electrical design, as they say it makes no difference what the polarity is in Einstein's work (Einstein says he might have got the polarity wrong) but it definitely does.

For example some think, when they design gear or routing of energy..that they are 'shunting down the drain' when enacting a high quality grounding system..but really..all they are doing is creating a excellent high quality pathway for conduction, if they analyze the electron flow considerations. Totally different viewpoint on the integrity, quality and reasons for grounding is the end result. Same as the analysis of polarity change in Einstein's work, if analyzed with the right eyes.

Sometimes, due to a circuit layout and design, a ground is just a ground - but in some circuits, it can take on a life of it's own. Sometimes it's best to commit to the mental exercise of thinking of it as being some giant resonant multi-chambered horn..and just exactly what end are you blowing into to activate the thing? And, depending on what end..what is the result?

Elk
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Re: My experience with Mysterious Hummmmm

Does any audio circuit designer not accept this?

When solving a circuit diagram you must consider the direction of flow. When contemplating grounding schemes you must consider the effectiveness of the ground plane, etc.

Of course there are always hacks, but this sounds like pretty basic stuff.

KBK
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Re: My experience with Mysterious Hummmmm

It is basic, but for some reason, some don't seem to get it. You can look inside the gear and see that, plain as day.

59mga
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Re: My experience with Mysterious Hummmmm


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... but this sounds like pretty basic stuff.

Yes, you guys are correct...this is basic theory. But all too often people forget the basics. As they say: When all else fails, read the instructions.

mjalazard
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Re: My experience with Mysterious Hummmmm

You may want to consider the Granite Audio Ground Zero:
http://www.graniteaudio.com/zero/index.html
This device has worked well in my system.
If you have any audio-visual (cable) connection to your system, there is agood chance that this can also be the source of the hum.
Jensen makes the Iso-Max CI2RR which really helps as well.
Good luck on losing the noise.
Mike

dbowker
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Re: My experience with Mysterious Hummmmm

Thanks NFS- I did consider that device, although as I said in my post, I found the source)s) of the hum: humidifiers set on Low in another part of the house. Easy solution----turn 'em off when listening to the music! No hum at all now.

The lesson I learned was if at all possible find the actual source of the problem, and get rid if it (again if possible). If that fails then it might be time to look to solutions like granite audio ground zero.

mjalazard
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Re: My experience with Mysterious Hummmmm

"The lesson I learned was if at all possible find the actual source of the problem, and get rid if it (again if possible)."

dbowker, your statement above rings true for most all situations...especially audio!

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