Bad House Power Causing Bad Tone?

[gbono]

Does your scope have a math utility to perform an FFT on the time domain data? I'm wondering if you have some particular harmonic "profile" in your area/grid. Also wondering if you cold try using some notch filters to see if you can remove the offending "tone(s)" from the audio signal chain. Your utility company should be able to survey your line/mains power with a recording meter that will collect data they must regulate.....

[km6xz]

When point out, almost anyone can hear what was suggested. Ask a hi-end hi-fi salesman, he uses that characteristic of humans as a major sales tool. The one with the best commission will be the best sounding.

I would put away the guitar and use a low distortion oscillator and scope and spectrum analyzer. If you do not have a high quality spectrum analyzer, no problem.
If you have a sound card you can download one that has low enough noise floor and distortion to easily see anything you can hear.

Visual Analyzer Download Select the Single file 2011

The one variable that is impossible to control is having the listener in the feedback loop of playing and hearing at the same time. As I always, tone is not so important but it is under the control of the player in case they want to. The signal wave form of playing is not a sinewave so after you get used to using the analyzer you can create your own custom waveform and have it repeat exactly without human influence on the waveform. I am going to guess that something in your playing changed and no one else can hear unless point out and suggesting it is there.

[soundguruman]

Does your scope have a math utility to perform an FFT on the time domain data? I'm wondering if you have some particular harmonic "profile" in your area/grid. Also wondering if you cold try using some notch filters to see if you can remove the offending "tone(s)" from the audio signal chain. Your utility company should be able to survey your line/mains power with a recording meter that will collect data they must regulate.....

Never depend on the utility Co. to reveal defects or problems. They will hide everything. They will give you endless runaround...

You are much better off having a licensed electrician measure (with the Fluke) and document first.
if the utility still ignores you, send the documentation to the FCC. FCC will investigate if all else fails.
Yes, FCC does investigate power interference...RF or otherwise. Not just limited to Radio Interference.
The Utility is required to comply with FCC standards...this will help you a lot, in the end.

But until you have documentation, expect no help...

II. The second thing that may help, cause havoc, is the Cable TV company.
Disconnect Cable TV from your house entirely, where it enters the building.
Does the noise go away?
Sometimes you have to use a CATV isolation transformer, which separates the CATV (trunk line) ground from your building ground.
All kinds of garbage noise winds up on the trunk ground....then connects to your building ground.
(AC/RF noise travels both ways, in and out, non-directional...)

III. Palomar Engineers has some dandy Ferrite Bead Kits, specifically designed to kill power line noise, RF noise, etc...
These things work surprisingly well.
Of course, documentation of the offending frequency is very helpful, again.
http://palomar-engineers.com/rfi-kits

[Leo_Gnardo]

It ain't the meat, it's the motion. For power, it's not the voltage, it's the waveform. All sorts of "garbage" can be riding atop an otherwise ordinary sine wave. When my neighbors use a blender, can opener, power saw, etc. I can hear the motor noise in guitar amps and on the stereo. And with so many appliances picking power off the peaks of the sine wave - it gets flattened off - with less power available for you and me. SCR/Triac dimmers take "bites" out of the sine wave, leaving it looking like - it's had bites taken out of it... All of the above resulting in a crappy power waveform, audio noises, and less-than-optimum amplification.

Our friends at Audio Asylum have been debating this problem for years. There are some solutions, the best involving rather expensive wave regeneration devices. You don't have to run the whole house off of one if you get it, just your audio gear, if you want things to sound right.

Nothing new either. @ 35 years ago I used to do work at a studio in NY Westchester County where aardvark noises showed up all day, randomly from @ 8 AM to 5 PM, in the plate reverb. When the auto repair shop next door closed for the day, the noises stopped. Turns out is was their welder. So final mixes were relegated to weekends and after 5 on weekdays. At another studio in Ft. Lauderdale 1984, a tik tik tik showed up in the plate reverb whenever an EC2 surveillance jet flew up the coast. Radar.

[g1]

As it has been almost a full year since the OP posted in this thread, I'd really like to know if he ever sorted out the problem.

[Leo_Gnardo]

As it has been almost a full year since the OP posted in this thread, I'd really like to know if he ever sorted out the problem.

Oh whooops! Didnt' look at the year. Ping Daver ! What's the answer?

Nonetheless the thread was revived, maybe we can learn something, also by having a look at Audio Asylum's discussions on it and especially those who claim they've found relief, and what re wiring, re grounding, noise bypasses & fancy gadgets they used.

The power company will be more likely to look into, and maybe fix, the problem if you're say, a studio with a monthly bill in the thousands of dollars. If you have a close relative who is an executive at the power company they may put in an extra "pole pig" transformer, just for you. I wonder how many people who generate their own power, for instance thru solar panels, who have these kind of noise problems.

With another change of year only 10 days away, I'll be lucky to remember to write 2014 on my checks. Sometimes I find myself about to write - - - 1986 - - Frank Sinatra voice - "it was a very good year."

Thanx for the "like" g-one!

[km6xz]

IF (very big "if") there was a problem, it was not power line, radio, or any of the paths listed in this thread. Why? There is no way a very subtle common mode or differential source noise would be impacting several different amplifiers in the exact same way. Being so subtle as he described it, how his friend only heard it after being told how to hear it, same with the sister, it would have to have been on the threshold of perception and any tiny deviation in noise sensitivity between the multiple amps would have meant at least one would have not reproduced it and one would have reproduced it a bit more, which if it was at the BDD level, being there or not would have been noticed.
No, the whole thread was either a joke or someone who talked themselves into hearing something so always heard it and was able to get others to agree, by the power of suggestion.

The FCC will not do anything....Their budget has been slashed and they do not do much investigation of any of the services under their control anymore. Long gone are the days when unmarked radio direction finder vans did regular TVI, power line, cable leakage, unlawful power level, broadcast etc interference investigations. They just do not have the staff anymore. Even back in the day, it took 6-12 months to rule on anything.
They might send a form letter to the power company at most. Their job is primarily to find frequencies for which the telecom industry can buy at auction. Auctioning off public assets is a gift to corporations and a loss to the country. They should have had conditional leases at most. That is another privatization that lowers the value of the real former owners, the human citizens. It was like the plan that did not succeed to auction off national parks to commercial operators like Disney, Universal and the Vegas casino corporations.