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Blow dryer causes audible buzz from power amps in two audio systems...

but only at one speed.  My wife's hair blow dryer causes the amps in both my bedroom system and family room system to audibly buzz.  It only causes the buzz when the blow dryer is on its low fan speed.  Strange.  The bedroom system is close to the master bathroom, where she uses the blow dryer.  But the family room is on the other end of the house and I assume on a completely different circuit.  Now, it does not cause any problem with the audio that the amps are producing.  It is just an audible buzz you can hear coming from the amp. Does this mean there is something wrong with the wiring in my house?  The house was built in 1987.
mtrot
Post removed 
lowrider57's avatar
lowrider57
5,397 posts
 
How will throwing out the current hair dryer help? They all have variable power settings.

isochronism
2,893 posts
 
Please no one suggest throwing the wife out....   but possibly would she get's a buzz cut?
millercarbon's avatar
millercarbon
12,531 posts
 
Appears no one so far has ever wired a house or paid much attention to how its wired. Takes about 90 seconds and a flat blade screw driver to see for yourself what is going on. If you’re worried about your wiring mtrot this will be worth it for peace of mind alone.

Three great big utility cables bring power into the panel. Two are connected to the breakers, one to each row of circuit breakers. Think of these as one being the 120v positive half of a 60 Hz sine wave, the other being the 120v negative half. Connected together they give 240v.

Easy enough if you want to flip a breaker off and pull it, which if you do you will see two great big copper bus bars. All 120v breakers connect to just one of these. All 240v breakers connect to both.

The third big cable is utility ground. Notice the utility ground is connected to a great big bus bar. Notice all the hot black wires come off each 120v breaker. Notice all the white wires connect to the same utility ground bus bar. So each of these seemingly separate 120v circuits runs from its own individual hot breaker through the house and your outlets and completes back at the same utility ground.

Might want to read the above sentence one more time. Because this is kind of hard to sink in. Because people have this false notion that circuits are separate when they are in fact all wired together. Pull the cover and see for yourself.


erik_squires
15,877 posts
 
This happens due to DC being inserted. It happens when the device takes high current from one cycle, but not the other. A number of things may do this, especially dimmers and high efficiency bulbs and LED power supplies. 


You could possibly fix this with isolating the bathroom circuit back to the main panel, but there's' no guarantee. 


The most certain fix is using balanced power conditioners, but they are expensive and not worth it for short periods of time. 
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