On 6/19/2014 10:49 AM, Tom Fine wrote:
> If there is dimmer hash in a home system, shouldn't the power
> transformer eliminate the problem by only passing low frequencies
> (60hz)? If not, I'm sure someone makes a non-ridicu-priced isolation
> transformer with a band-pass. I don't have any dimmers or anything else
> that rides on the power lines in my house. However, the place is full of
> RF from wifi, cellphones, radio and TV, etc. Never had any problems with
> RF or hash. Regarding dimmers, if you like listening to music, consider
> whether you really need dimmers. I view them as a useless cheezy fashion
> trend from the 70s. Just use the lightbulbs you need to do the job.
> Granted, it's harder in the age of non-incandescent lights, but it's
I agree, dimmers are dreadful. But some people have them.
The bad news is that some of the crud gets broadcast out into the ether
rather than into the power lines. So it can get picked up by cables and
piped into the inputs of equipmwnt -- and phono systems, alas, don't use
balanced connections. If they did, life would be simpler. As it is,
ferrite beads are useful for keeping the crus out of the audio circuits.
The dimmers might be in the house or apartment next door and still
One of my biggest challenges was building a phono preamp for my parents'
apartment on Chicago's near north side. There was dimmer crud from
adjoining apartments, but the worst problem was the antenna farm on the
Hancock Building, 0.75 miles away. Taxi radios were occasionally an
issue too, though not as much.
Worst was a pair of phono preamps that lived 10 feet from a 22kW FM
transmitter. That was a challenge.