different power grids (BS or not)

[Dale W]

Now heres one for debate. Recently i returned a bad cable to my local dealer (causeing some noise problems).Anyway i get talking to the tech guy there and he tells me that he also had a hum in his mutli channel amp and believes that the problem was caused by a "dirty power grid". The hum appears at his residence but take the amp across town to his brother inlaws house and guess what no hum.Now i stood there with my mouth shut and said nothing as this is not my field of expertise. Was this guy just showboating for me or is this a possibility ?

[lynnm]

It could be a problem with the wiring in his house.

[Ray Garrison]

"...but touch the amp across town to his brother inlaws house and guess what no hum..."

Assuming you meant "...TAKE...", cause if you just touch an amp that's across town and it changes the humm in your house that'd be pretty cool...

No, he was not pulling your leg. The term "power grid" is inaccurate, as the power grid refers to the collective transmission and distribution facilities of an entire region (as in "The New England Power Grid", which encompasses Maine, New Hampshire, Vermont, Massachusetts, Rhode Island, Connecticut and part of upper New York). However, there is absolutely a possibility that the local distribution system serving your part of town and that serving some other part of town could have very different levels of hash, noise, and general nasties. This is one of the vexing problems that is preventing local utility companies from offering some sort of high speed data link via the power lines. Something that works fine for customer A is useless for customer B.

For example, if the brother in laws house is on a spur that serves only residential areas, and there's not a lot of drops, and it's fairly new construction, you could be looking at a mains that has very, very low levels of noise and distortion. If the tech guy lives in an area where his local drop is part of a system that is serving, say, an industrial park or other commercial customers, some of whom have big, old, noisey equipment that's dumping a lot of noise and hash into the neutral, you'd be amazed at how much of that works its way through the power supplies and into the sound of your system. This is one reason why some people find night and day differences when installing power conditioning equipment (Monster or Chang or whatever) and others find no difference to speak of.

Ray, ex Senior Computing Support Specialist for the United Illuminating Company, New Haven, CT

[Dale W]

Ray: sorry about the typing error, i corrected it.

So i take it from your comments it is a possible then?

I had no clue, thats why i said nothing.

Very intresting: thanx

[MrMcGoo]

Dale,

Power conditioners can, in some instances, make a major difference in sound quality and equipment safety. Noisy power cuases major problems with anything digital. My receiver has as many microprocessors as my PC.

One fellow on a different forum allegedly blew up six different high end receivers. His solution was to move to a cheap receiver.

I have never lost a component prematurely. The whole house is on a surge supressor built into the base of the power meter. I use multiiple Panamaxes in the home theater. I do not think that I have wasted any money. I cannot count the number of times that the Panamax has had to shut off the power to my system due to a sustained over or under voltage problem.

Some folks even use uninterruptable power supplies. I find no fault with their decision.

The builtin voltage meter on my Panamax routinely varies over an eight volt range. The power distribution system was designed long before the digital age. Good power conditioning is inexpensive and worthwhile in my view.

Bill

[JohnA]

It's hard to imagine dirty AC power causing hum. It can easily cause pops and clicks and if your gear's power supply is poor, I can see increased distortion since thee will be an AC ripple on the, supposedly DC only PS busses to the amps.

Several years ago I was standing in my house looking out and saw a flash in the woods. Never thought twice about it. A few days or weeks later, weird things started happening to the lights and appliances in the house (flickering, dim/bright cycling, hard starts). I started checking my house voltage. Things on one side of the breaker box had higher voltage than the other. The reason turned out to be a broken neutral back at the distribution pole (the flash). A broken neutral (ground) or a corroded connection for the Neutral/ground could easily cause a hum in one house and not another. The break could be in the house or at the pole.

I can't remember anymore if I had hum in my audio gear.

(I can't resist Ray ) I work for the country's largest electric power producer.

[BBB]

Absolutely correct John. At last I found someone else who had a problem with the neutral in their home. I had the same things happening to me as you described. In my case it was and may very well still be a corroded or broken neutral in the house. I had 3 different electricians crawling all over this place trying to find what was going on. The problem is I have 5 breaker boxes in this place and some are feeding off of others and the problem is intermittent in different parts of the house. Its a nightmare you can not believe until it happens to you. I had an electrical contractor friend over one day and he told me it was a neutral problem somewhere in the wiring in the house that could be affected by temperature, moisture or even vibrations. Oh for joy! When they started talking about cutting through walls I put the breaks on and just had some of the problem outlets rewired and had the old wiring disconnected. Its a long story and a hassle that no power conditioner could ever fix. Is there any wonder why they call me Bugsy ?

[Dale W]

See i knew this topic would spark some intrest thank you all for your imput:

JOHN : do you work in the generation of eletricity or disturbution side ? I'm very intrested in power engineering as for the actual production of electricity. I made a return to college at age 35 and completed my 4th class power engineering certificate and then the 3rd class. I then aquired 500 hrs of high pressure steam time, enough to write the provincial exam for the forth but i'm still short steam time for the 3rd class, but i've written the first two out of four provincial exams for the 3rd. Here in alberta we have some of the largest coal fired power plants in the world, some are 15 stories tall with massive combustion chambers. I'm trying to aquire a position at one of these generation station as i can't get enough of working on or with this type of equipment.The automotive industry has been good to me for the past 20 years, but my true passion is with power engineering.I get goose bumps every time i fire a boiler and warm up a steam turbine to bring a generator on line. The ones I've worked with are olny small 100kw units but it's still fun to spin up a impulse turbine and get the generators humming.600kpa is all i'm certified to operate on my own but even thats a blast.

BILL: I run two monstercable ht3500 line conditioners and have a seperate ground fault interupter breaker just for my stereo equipment. Your right !! better safe than sorry .

[JohnA]

Dale,

I work in Fossil Engineering for all 11 of our coal-fired and 5 combustion turbine sites. I have even been to Operator School to "run" the simulator of one the 200 MWe units. The school puts on a class every so often for engineers. A few years ago, they started sending all of us to the real Operator school, because Management feared a strike. It was cool. I only got half way through before the conflict was settled. I have a HUGE fascination for machines, from small ones like handguns and clocks to 1300 MWe turbines and 3500 psi boiler feed pumps. It's so bad, I took a tour of a coal-fired plant in Australia while I was there on holiday. I shouldn't have told that when I got home.

Besides learning all I can about the plant, my job is civil engineering for the yard operations at the sites.

[Audio Flynn]

John I figured you for a "Toolie" on the edge.

I am pretty much automotive exterior plastics engineer, my good friend is Safety belts and airbags. Gave me a book to read I need to find a copy of.

It is called "Toolies how to know if you are one and how to avoid being one if you are not"... or some crazy title like that. The book was a hoot for any engineer or techie to read.

The other community of humans was called the 'arts and craftsies' as I recall.

I go on holiday and look at bumpers molded of the competitors material as I walk through parking lots to see if any exhibit brittle failures from minor fender benders.

I have issues as well.

[djk]

"It's hard to imagine dirty AC power causing hum"

Oh ye of little imagination!

The guy across the alley from you is on the same transformer you are. He owns one of those 300W halogen floor lamps. It has a Hi/Lo switch. In the Lo setting it switches a diode in series with the lamp so it runs off half wave rectified AC. This causes an imbalance, or net DC current component to flow through the transformer on the pole. The same one that feeds your house.

You own an AArdvark 99 power amplifier with a toroid transformer. Toroids don't like DC on the primary. It makes the core HUMMMMM.

Oh, by the way, that expensive power line conditioner won't help you with this.

http://www.hifi-notes.com/images/offsetkiller300i1.jpg

Note the three diodes in series, with another three diodes in series connected in reverse parallel. It also has a 2 ohm (cold) inrush current limiter. The common mode filter and MOVs are optional.

[Dale W]

AUDIO FLYNN : Hey back off on the pure PP and EP your making my life at work a living hell. lol

nothing wrong with the olefine family ( ha ha ha ).You build them i'll figure out a way to paint them.

[Dale W]

JOHN: I'm the same way , i don't own anything that i havent taken apart to see how it works. (inculuding my dishwasher, really pisses off my wife). I watch very little tv but spend most of my free time reading tech books on any topic.

with the warmth of my klipsch gear in the background.

Right now i'm very intrested in hoover crafts and want to find a two seater that needs to be restored. I grew up in the very north part of manitoba and use to ride in these with my dad. Back on our farm we have a old snow plane that i also want to bring home and restore some day.

signed : Can't leave well enough alone !! Dale .

[LOADEDTUNES]

DALE : you are truly a freak in need of some couch time. lol !! Thanx for sending me the info on that threshold amp,i do believe i have it wired correct now.

I firmly believe garbage can be transmitted though ac lines. My gear goes crazy when the wife fires up a electric knife or mix master.

[lynnm]

Quote:

I grew up in the very north part of manitoba and use to ride in these with my dad.

What town did you live near ? I lived in Thompson for a couple of years.

[Prana-Bindu]

Try this experiment, and also do it with your power conditioning equipment installed: pick a track of music with which you are intimately familiar; play it during the day on a weekday several times (over several weekdays?) and really get to know how it sounds; then play it late at night a few times (3:00 or 4:00 in the AM). Notice a difference? I did.

[Dale W]

LYNMM : TOO COOL !!!!

Thompson was the place. My dad was the service manager at mystrey lake moters and we lived at #24 davis bay.I lived there from 1969 to 1974 and moved to alberta at age 10.

I would love to take my kids and go back to visit some day. we use to park our trailor at paint lake all summer. Great place to grow up if you love the outdoors as i do. When i moved to alberta i was one tough kid who was use to being chased to and from school by the local indian kids. I'm sure i've been in more fights in one day than most guys in there whole life.

Things have likly changed a lot since then. I was born and raise in southern manitoba in a small town called RESTON. Our family farm is just outside reston and i try and return to the simpler way of life when ever i can.My whole family is either farmers or mechanics so i learned at a early age how to fix my own stuff.