Half-a-brain loonies and internet geeks

[SteveTheShadow]

Now this is interesting!

I use a pair of homeplugs that use the mains wiring as an ethernet network for the Squeezebox, one by the computer and the other plugged into the same power strip as the DVD player, the TV and the Cable box.

That puts me beyond the pale, so I suppose any opinions I might have or might have expressed regarding hi-fi equipment and its sound quality or lack of can be completely dismissed as nothing more than the rantings of a fool My credibility was pretty tenuous on here before this revelation...now it must surely have been shot to pieces.

Steve

[Marco]

LOL!

Steve, not everyone is a lunatic like me with a dedicated music room and will go to the same extreme lengths with a hi-fi system and the mains, not to mention whatever else is necessary. 'Normal' folk live in the real world where living rooms have 'stuff' and children in them getting in the way, along with the hi-fi, so just continue building your very nice speakers, etc, and ignore my ramblings

You are anything but a fool

Marco.

[tfarney]

Tim, there *will* be (measurable) noise present in your system as a result of your digital computer gear (it's the same with my CDP and DAC), but your ears won't hear it as such: it will be translated as distortion, manifesting itself on music signals, and thus the sound reproduced by your hi-fi system (heard through headphones or whatever) even if you don't realise it - there is no getting away from this unfortunately. That's why filters are designed for the purpose and these can be shown through measurements to demonstrably remove the noise created as described above, the only thing is that most filters in doing so remove some of the music, too, hence why I, for example, don't use them and simply optimise my room and my system in such a way that any noise generated by the aforementioned items is minimised as far as possible.

Well, Marco, all I can say to all of that is that someone is going to have to explain to me, with some credible science and some good references, how it is that noise in my system, which is below the threshold of human audibility, can somehow attach itself to my music, hiding its very noise-ness, and manifest itself as a distortion of the sound field or frequency response or whatever. I heard the noise. I separated components into separate circuits. The optimization, without filters, you speak of above. The noise dropped below audibility. Yet you tell me it is there, quite audible, riding the notes like little parasites, transformed into something else entirely?

You're going to need some serious science to back that up, my friend. I don't trust your ears on this one, and neither should you.

By the way, I sell the aforementioned filters. They are designed to remove noise, not musical distortion. The noise they remove only distorts the music to the extent that it is audible enough to mask certain frequencies, but in all but the most extreme examples, the opposite is the case. And they remove the noise from the power supply (not the one in your amp, the one in your wall), before the music is even in the loop, so it is quite impossible for them to filter some of your music too. Perhaps I misunderstand. Are you talking about some other "filters?"

Tim

[Marco]

Tim,

Well, Marco, all I can say to all of that is that someone is going to have to explain to me, with some credible science and some good references, how it is that noise in my system, which is below the threshold of human audibility, can somehow attach itself to my music, hiding its very noise-ness, and manifest itself as a distortion of the sound field or frequency response or whatever.

RFI and EMI (effectively forms of noise) are known phenomena and exist in your mains supply so therefore adversely affect the performance of audio equipment connected to said supply - you can look up exactly what they are (and their effect) on the Internet

You can partially filter out RFI and EMI in your mains supply, caused by computers and such like, and as far as our interest in hi-fi systems go, anything emitting an electromagnetic field near sensitive audio circuitry, but normally it comes at a price - and that price is the removal of some of the music signal with it. I can't speak for your filters as I haven't tried them, but they'd have to be different from every other ones I've tried, which all 'sit' on the sound in a negative way.

Marco.

[tfarney]

Tim,



RFI and EMI are known phenomena and exist in your mains supply - look up what they are (and their effect) on the Internet

You can partially filter out RFI and EMI in your mains supply, caused by computers and such like, and anything emitting an electromagnetic field near sensitive audio circuitry, but normally it comes at a price - and that price is the removal of some of the music signal with it. I can't speak for your filters as I haven't tried them, but they'd have to be different from every other ones I've tried, which all 'sit' on the sound in a negative way.

Marco.

I'm familiar with noise in power, Marco. I'm also familiar with where it is introduced to the signal chain, which is prior to the introduction of any musical signal, or even any digital information. This is where it is filtered -- when and where there is nothing but electrical power. No music. No data. Just voltage and noise. If filtering it there "sits" on the sound in a negative way for you, I can only conclude that you miss the noise.

Tim

[Marco]

Indeed. I think you know full well what I mean, though

It's all very well filtering the mains at source (before the music signal) but that doesn't stop equipment in the replay chain later (a computer in your case, for example) putting electrical noise back onto the mains supply as a result of the function of its SMPS when switching kicks in.

The only way to cure the noise is to remove the source of the interference: in your case, your computer. Personally, I wouldn't have one near my hi-fi system. When I invest in a computer audio set-up, the PC or laptop will be kept in a totally separate room, away from the rest of my gear and on a different electrical circuit. I will simply use some high quality low-loss cable to hook it all up.

Tim, we could go round and round in circles all night debating this and in a real sense get nowhere. I *know* what I hear; if you choose to dismiss that then it is your prerogative, but there will never be an occasion in hi-fi when after thorough listening that I don't trust my ears implicitly, whether in the absence of scientific reasoning or not, because they are bloody good and have never let me down yet!

Marco.

[tfarney]

You misunderstand me. If you hear noise introduced further into the signal chain, by computer or cd player or toaster, they're your ears and you must trust them. But if filtering power, prior to the introduction of an audio signal seems to somehow remove some part of that audio signal for you, well, your ears have managed to violate not only physics, but the time-space continuum.

Again, perhaps we're talking about different filters. Are these fitlers of which you speak in the audio signal chain somewhere?

Tim

[Marco]

Yes, we appear to be talking about different things!

What I'm referring to are simply filters which plug in-line with the mains supply, normally near the point of a mains power strip, although I don't use such things. The ones I've installed there so far have all had a negative effect on the sound.

Marco.

[tfarney]

Yes, we appear to be talking about different things!

What I'm referring to are simply filters which plug in-line with the mains supply, normally near the point of a mains power strip, although I don't use such things. The ones I've installed there so far have all had a negative effect on the sound.

Marco.

No, if I understand what you mean by "mains" I think we're talking about a slight variation on the theme. The filters I'm thinking of are typically built into the power strip, but in more or less the same place. Are these filters somewhere between the power outlet on the wall and the first audio component? Are they designed to filter noise from power before that power reaches your system?

Tim

[Marco]

Are these filters somewhere between the power outlet on the wall and the first audio component? Are they designed to filter noise from power before that power reaches your system?

Yes, and they are normally plugged into a power strip or wall socket, which the system is connect to.

Like I said, the ones I've tried so far installed at that point in the mains supply have all sat on the sound, apart from one which Anthony TD designed and brought to me a few months ago, and which I'll be looking into in more detail, but the likes of Russ Andrews Accessories stuff, Vertex AQ, and countless other types I've tried, have been crap.

Marco.