Well, you're not the one who is confused. The question I don't know the answer to is whether the confusion elsewhere is genuine or deliberate. In any case, perhaps the next question will be what the correct hfe for a transistor should be.
I haven't played as much with those, but AC receptacles can make a large difference. Wait, do you mean something different than changing the plugs?
I suppose so, but I'm always up to discuss differences in our findings too!
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Nah. Actual issue! The primary for a power transformer is wound close to the core. If the innermost winding is tied to the neutral on some and the hot lead on others they both will couple capacitively to the core which is either connected to ground/common or capacitively to the secondary. This will cause a current to flow on the shield of the RCA interconnects. As the line leakage is capacitively coupled it is a high pass filter. The AC mains noise as shown before basically drops by 3 dB per octave from 60 Hz. Throw in Fletcher Munson weighting and the noise peaks just about where your sensitivity peaks in the midrange.
For some numbers I measured about 1 uA leakage in off the shelf transformers. With an IEC standard load of 20,000 ohms that would be 20 mV for a grounded frame unit!
Also note the close spacing of the harmonics by the midrange means you hear it as noise not buzz.
We disagree again, the phase relationship is fixed not random in the simplest case the spectra of a pulse train (highly likely considering dimmers, etc.) definitely easily differentiated from noise.
Noise as in extraneous signal that should not be there/unwanted or noise as in thermal or random. I think it is clear from the description which is being talked about.
It seems you disagree only to be argumentative.
THx-RNMarsh
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It sometimes depends on the coupling to ground..... The C to grnd is not the same.... asymmetrical.
THx-RNMarsh
No, I'm interested in facts. Produce a signal comprised of 60/50Hz and their harmonics only with amplitude decreasing at 3 or 6 db per octave that sounds like random noise and I might agree with you. When I set the volume to normal listening level with no input I hear nothing at all, what's the problem? Someone somewhere in time made a pathologically bad amp/pre-amp so what?
I think building the expertise for competent analog electronics design has been fun, exercising it pleasing to me
but that doesn't mean I ignore psychoacoustics, transducer/recording/speaker limitations - I'm pretty sure that the electronics for adequate fidelity isn't anywhere near the first order limitation in home recorded music reproduction
when people start talking about, say, "natural holographic imaging" of amp or DAC I remember reading mixing engineer's blogs and books about how it is "painted on" in the studio:
9 Psychoacoustic Sound Design Tricks To Improve Your Music
but that doesn't mean I ignore psychoacoustics, transducer/recording/speaker limitations - I'm pretty sure that the electronics for adequate fidelity isn't anywhere near the first order limitation in home recorded music reproduction
when people start talking about, say, "natural holographic imaging" of amp or DAC I remember reading mixing engineer's blogs and books about how it is "painted on" in the studio:
9 Psychoacoustic Sound Design Tricks To Improve Your Music
This is one of the bits of silliness prevalent in audio mags---the valuation of minimal crosstalk as somehow translating into better imaging. What rubbish! The threshold of localization as a sound coming from one of a stereo pair of loudspeakers, as coming entirely from that one channel is...wait for it...a level difference of 13dB! AT BEST (and absent any time delay effects, which are far more important if present). And this is before we consider intentional cross-feeding, which of course makes crosstalk measurements of a conventional sort ludicrously irrelevant.
That fact (obtained from Toole in a quick query) came to my rescue when I was arguing in a phone call with a very Harman-negative individual at Compaq, who insisted that a crosstalk measurement be cause for redesign in a super-cheap powered loudspeaker. What made it additionally ludicrous was that the actual crosstalk signal was mostly distortion arising on the amplifier chip getting into the other channel, not the fundamental.
After some barely civilized exchanges with Mark B., the guy's boss Jay Smith said (imagine the Texas drawl here) Well I like to say sometimes it's time to shoot the engineers.
I said Well Jay. I have the gun aimed at my head. How do things look on your end?
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