Having experienced - and able to replicate at will the behaviour - the sensitivity of my audio equipment SQ to items like mobile, cell phones, I think it's more the case of someone proving to me that there can't be RF linkage ...
Yes, the D/A area is critically sensitive, and it would probably be extremely difficult to design a circuit with true galvanic separation here; however, even relatively standard DACs will perform well, IME, if enough tweaking is applied ...
The coupling exists, somewhere - otherwise the audible problems wouldn't arise. At the recent hifi show a room that had very good SQ, changed to a different digital source to the same DAC - the SQ degraded significantly, developed the classic symptoms of "digititus". Handwaving that it can't be so doesn't change the fact that ears could hear it ...
Huuuh?? I'm recognising, reacting to sound that's occurring in a listening environment - what's electronic mechanisms got to do with that?
qusp,
Just give it up with Frank already it just encourages him, and then John comes in and does the same. The fact that I could write a computer code here in Cali, on my computer, send it to you over how many copper wires through any number of fiber optic cables, have it converted back to a copper wire connection and you can receive a perfect bit for bit copy down under and use that on your computer means nothing to Frank. Somewhere between you and me he just intuitively knows that some insidious RF has been added between the bits and is just lurking in the background waiting to escape.
Frank I'll give you that there is nothing perfect in the analog world but there is a point of diminishing returns where some things are below our ability to discern them. We do not have a hidden latent ability to hear at the level of a bat, we did not develop our hearing to this level, we had other ways to integrate our hearing and sight and touch that did not necessitate that level of detection. Perhaps you are that missing link and have become that genetic outlier that has through convergence developed extraordinary powers!
Just give it up with Frank already it just encourages him, and then John comes in and does the same. The fact that I could write a computer code here in Cali, on my computer, send it to you over how many copper wires through any number of fiber optic cables, have it converted back to a copper wire connection and you can receive a perfect bit for bit copy down under and use that on your computer means nothing to Frank. Somewhere between you and me he just intuitively knows that some insidious RF has been added between the bits and is just lurking in the background waiting to escape.
Frank I'll give you that there is nothing perfect in the analog world but there is a point of diminishing returns where some things are below our ability to discern them. We do not have a hidden latent ability to hear at the level of a bat, we did not develop our hearing to this level, we had other ways to integrate our hearing and sight and touch that did not necessitate that level of detection. Perhaps you are that missing link and have become that genetic outlier that has through convergence developed extraordinary powers!
I give it to Frank that he hasn't mentioned a single example in all this time, not a single detail, on how he does his holistic system thing.
In a way, that's quite remarkable.
By ear. You couldn't possibly understand.
The key, for those of us with the wisdom to appreciate these gems, is the interaction of air currents from handwaving, hot air from pontificating, and the vacuum created by lack of data with the sound waves coming from YouTube videos played through his laptop. Mud interconnects enhance the experience. This is far more profound than the mundane tasks of actually designing, building, and testing of hifi equipment.
It's even more remarkable how I've mentioned over and over again the sort of things I focus on worrying about improving, and it seems to whistle straight through the apparently somewhat common empty spaces between the ears, of some of the people on the forum ...
True, I just focus on improving, but worrying is not my thing.
I'm truly a lousy student.
Okay. Last system fiddle was the cheap TV thing, I described exactly what I did so anyone could copy the procedure, and invited interested parties to try it, and report back. Didn't get a single response, guess that must have been my fault too ...
Implication is that there is a mighty impressive lot of engineering and scientist talent here, who already know the outcome to a simple experiment, without in fact trying it ...
Implication is that there is a mighty impressive lot of engineering and scientist talent here, who already know the outcome to a simple experiment, without in fact trying it ...
Frank,
I have done a PCB with a SMPS and the audio circuitry that fitted in the ear shell, there was no interference that was audible from the SMPS.
Do you connect your cable shield at both ends of the cable at the point of entry to your equipment? or do you follow the audiofool fallacy of only connecting one end of the shield, and/or use pigtails from the shield to some system star point?
I have done a PCB with a SMPS and the audio circuitry that fitted in the ear shell, there was no interference that was audible from the SMPS.
This I would suggest is down to your gear, your modifications and your shielding.
Do you connect your cable shield at both ends of the cable at the point of entry to your equipment? or do you follow the audiofool fallacy of only connecting one end of the shield, and/or use pigtails from the shield to some system star point?
I have only worked with audio gear as available in retail form, which have plenty of openings allowing for RFI infiltration. Unless I approached the whole exercise virtually like a military operation, I wouldn't have faith of achieving sufficient immunity - the concept of having all interconnections running through full blown metal conduits, so that effectively there is a unified chassis around everything appeals to me ...
A disturbing exercise was placing a mobile phone inside a closed microwave oven, and ringing it. Yes, it answered - so how tiny should the gaps be to really be sure ...?
Hear Hear, exactly the reason I am (still) here, and highly grateful to them for sharing their mind, knowledge and expertise.
I do listen, do read, and do assume to understand what it is I read. In case I do not, I just ask, politely.
Doesn't imply that I have to agree all the time, often it's just a mental exercise.
For example, when some talk about annealing & tensile strength, I could write about the relative thickness of the aluminum layer and the location of the neutral plane in the 1.25mm thick disc. And a couple here, just love the smell of thermoplastics in the morning.
Nèèh, boring.
More of interest is the dialogue, and a glance through another's eye perspective.
By coincidence, one of the most vital things I've thoroughly been trained for.
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Nah, not a problem. The seal gap along the edge of the door is a 1/4 wavelength long waveguide/stripline. It appears like a short circuit within the oven because the other end of the waveguide is terminated by an open circuit. So it is designed with a specific frequency in mind.
Cellphones are not the same frequency.
Here's a little detail..
Note the paragraph labeled Quarter-wave stubs, first two sentences.
Starting with an open circuit, one quarter wavelength away you will "see" a short circuit. Starting from a short circuit, one quarter wave away you have an open circuit.
Quarter-wave Tricks - Microwave Encyclopedia - Microwaves101.com
jn
From the premier AES Digital Audio Conference 1982 I quote from Barry Blesser in the keynote paper. He is discussing the residual expansion A to D, "An error of +- 1 LSB in the 8 bits can be tolerated with no final error". The problem with these is that they need very good stability and drift in the analog residual amplifier chain they are not inherently only 8 bit integral linearity. His example was 8 bit first then the residual at 9 bits.
EDIT - BTW I noticed that by 1982 the absolute necessity of dither was underscored by many.
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Indeed, it is the process of 'mastering'. More often than not, the mastering degrades the sound.
Indeed.
One thing is that most CDs masterings degrade the sound a lot.
Another thing is that not all CD players and/or DACs are created equal. Only few sound good enough to me.
On top of that, possibly, many CDs aren't manufactured to a 'good enough' standard.
As goes for CD-R's, some are unreadable on the 2nd go.
(btw, Joshua, A+ for the previous post, you went from -5 to plus 5 on the shopping list, in one go)
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