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John Doe[_2_] John Doe[_2_] is offline
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Default Where does the hum come from?

(Don Pearce) wrote:

John Doe wrote:


https://images-na.ssl-images-amazon....AC_SL1500_.jpg

Nothing is connected to that optical input DAC. No power. No signal.
Nothing. Doesn't matter whether the antenna is connected or not.

With the powered speaker (JBL LSR305, -10dVB, volume maximum) input
disconnected, with its speaker wire dangling from its input, there is
almost 0 sound from the speaker except an extremely faint wind sort of
sound with my ear up against it.

Humming begins when the speaker wire is plugged into the disconnected
DAC.

Why is that? The DAC isn't connected to anything else. Does it act as a
receiver/antenna?

The humming sound is low enough so it makes little difference, but it is
noticeable.


Why are you plugging a speaker wire into a DAC? Speakers are plugged
into amplifiers. Are you saying that your system hums, and if you unplug
the speaker the hum stops?


I don't know where to start re-explaining. I thought that was verbose.