DIY hifi source

[fas42]

Originally Posted by marce

Fas42, two points, you cannot design any equipement without measurments and the tools to perform those measurements, yes you have to listen if its audio based, look if it is picture based etc, but contary to what some gurus would have us believe, you cant design by ear alone. I think some loose touch with the fact that audio equipement designs is like any other branch of electronics it is engineering, some seem to forget this (or like to create a mystique) thinking they are a Stradivari creating an instrument, they are not they are engineers (you would hope, though wonder some times) creating some electronics to provide the best fidelity in playback equipement.

If the measurement gear was set up in a sophisticated enough way so that the readings correlated to how the ear/brain registered "quality" then there wouldn't be a problem. However, this has not be done as yet, as far as I'm aware; so the fallback is the hearing system. My own experience is that there is a plateau of quality possible with audio gear, which probably doesn't correlate well with any conventional test readings, and which is good enough for me. So far I've been able to reach that plateau on a regular basis by using engineering skills in solving theoretical and practical issues, I don't need readings from an instrument to "prove" to myself that it's better, though I'm sure that if I did plenty of times there would indeed be better numbers ..

Frank

[marce]

In other words, the fact that they are stored in different locations means that there is a different pattern of electrical activity when they are replayed. And the fact that one is played after the other "changes things". This might seem all terribly subtle, but I've dealt with headaches along these lines over many years; the physics of everything does come into it, unfortunately ...

the bits dont care thats why we have digital and why it is so prevelant these days, from source right up to the DAC, if the bit pattern is the same the data is EXACTLY the same, no difference whatso ever. Thats why we store data in digital format!!!!!!!!!
To paraphrase:
its so wrong that I dont know where to start...

[marce]

Engineering requires measurement and metrics to work to, sorry if you think different but you are wrong.

[sofaspud]

What "pattern" do you mean?
Are you saying no two playbacks are the same (from any source)?
"The physics of everything"??

[qusp]

yep, 'fact' and 'engineering' seem to be synonymous with 'hair-brained theory' and 'fumbling in the dark' respectively

[sofaspud]

I'll bet anyone that when the anti-measurement folks work, they want an accurate clock, when they buy tomatoes they want an accurate scale, when they buy gasoline they want an accurate pump, and so on and so forth. Any takers?

[sandyK]

lets say for arguments sake that you are correct, it still has nothing to do with the file, nothing at all; it would have everything to do with the playback mechanism.

Martin Colloms and many others now, do not agree with you.
Not only can 2 .wav files with identical check sums sound a little different,
3 .wav files with identical check sums can sound a little different to each other! This was also verified very recently in a U.K. based forum as a result of 3 uploaded rips of the same .wav file.

Rip 1: rather mid fi CD sound perfectly good if you did not know better , not very communicative or involving set at 50% approx score

Rip 2: makes 1 sound dulled , less detailed , less transparent , softer dynamics and bass definition

rip 2 has more musical expression better listener involvement and clarity, higher resolution without a doubt ( I have heard the master tapes)

75% approx , very natural, accurate effect, firmer clearer bass lines , greater depth and atmosphere , more extended instrumental decays

Rip 3 : The latest rip, ( with another power supply upgrade to the ripping drive ) better still in some respects, but not others, eg more convincing micro dynamic resolution in far depth plane, still more detail and focus, but

not quite so relaxed , flowing , musically involving, sounds slightly artificial and mannered , a 'spotlit' character

so a moderate loss of quality to 66% - Martin Colloms in HFC Forum

Kethel ripping results second session - General HIFI Discussion - HIFICRITIC FORUM - HIFICRITIC FORUM : hi fi audio systems forum

[fas42]

The device that performs the playback, say the PC, has a different sequence of electrical activity occurring for the two files. If one were to apply logic probes to numerous points on the motherboard and record every single logic state transition for the entire track, for the two files, they would be two quite different records. If you then accept that electrical activity in the digital side of things could possibly influence the analogue quality via all the usual suspects then you have the recipe for varying playback.

The "physics of everything" means exactly that: on the second playback the suspension of the speakers or headphones has warmed up a bit more, all the capacitors around the DAC are a touch more "conditioned". Yes, yes, this is all very subtle, but if one is busting to pick up a difference then this is how the little "clues" can be there.

Frank

[fas42]

Originally Posted by sofaspud

I'll bet anyone that when the anti-measurement folks work, they want an accurate clock, when they buy tomatoes they want an accurate scale, when they buy gasoline they want an accurate pump, and so on and so forth. Any takers?

Accuracy is not the problem, it's relevance: if buying tomatoes the scale measured the colour rather than weight then the customer would be scratching his head. Audio gear with excellent "measurements" often does not create pleasing sound, so the customer again scratches his head ...

Frank

[marce]

We are discussing the possibility of bit identical files sounding different, not any noise problems, the link provided stated that though the recorded bit pattern was the same they sounded different due to better power supploies in the ripping equipement. This would mean by deduction that somehow this noise has been recorded with the bit pattern, how, when during playback the data will pass through many intermediate storage buffers, cache, DDR etc and at each stage the data is recreated.
That is the claim, and so I would like to know by what mechanism this is happening.