2. misc-audio
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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

Showing 2 responses by petg60

petg60
1,486 posts
 
Hi mtrot,
DC is induced in the line, refrigerators, heating elements....hair dryers (especially). Has nothing to do with new or old houses and lines. DC can be picked up even at nearby station and distributed to your house easily. Can only be cured with the addition of DC filtering (i have tried it it works). Apart from buzzing noises more heat is generated also.
petg60
1,486 posts
 
Hi,
DC present in line is common and is not minimized or eliminated if you have a dedicated line for Audio and does not go away if you use different wall sockets. A nearby station may also be affected occasionally and distribute DC to your home line easily. To make things more complicated not only hair dryers but dimmers, refrigerators, led power supplies, micro wave ovens load DC to a line. Few audio equipment use DC filtering, the rest are more sensitive and their transformers will produce noise and heat most of the time. I have found a way to eliminate the problem through a dedicated DC filter (made of 12x 4700mf/25v caps, one for Power amp and one for sources and preamp). Sonically they are not subtracting .
George
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