Yes, I understand how these work. My question was more about why the explanation where noise from the first stage of an amplifier is fed back (negated, inverted, or, ?) to the input which seems much like a noise-canceling headset to me. I inferred from the sighs that the previous explanation was incorrect and (sorry) but I don't understand why that's the case.
Were the "sighs" meant to indicate that the example given was incorrect or, perhaps, just more of the same already-covered explanations? Sorry - sighs can a bit more meaningful when combined with an eyeroll.
Thanks,
Barry - N4BUQ
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----- Original Message -----
From: "G?ran Krusell" <mc1648pp@...>
To: [email protected]
Sent: Thursday, March 25, 2021 3:18:58 PM
Subject: Re: [TekScopes] How to explain how negative feedback lowers noise?
Hi Barry,
No sighs from my desk, your question is a good one. I think these modern
headphones work in the following manner, a small amount of noise comes
through the leather in your headphones. At the same time the external noise
is picked up by a small microphone in the headset, amplified by an inverting
amplifier and added to the direct noise to you ear in equal amounts. The
noise is thus attenuated. And it does work, I have one such headphone from a
well-known company.
G?ran
