When I finally settle, I should go hunt down my grandpa's old Nakamichi player that was collecting dust at my parent's house. Not sure if it still works, but man, it was sure cool from a user-experience perspective.
(I'm all for embracing the theatrics for the joy of it all)
(I'm all for embracing the theatrics for the joy of it all)
Thanks Waly I stand corrected, I'm not immune to doing stupid things. BTW Jaz Coleman and Test Dept are doing something in Paris Friday wish I could be there. Old school TD is missed here.
L'Étrange Festival - XXIInd edition - September 7 - 18 2016 - L'Étrange Musique
Been done about 10yr. ago. My idea was to record a complex symbol something like a pseudo-random noise of length 44100 or 1 second on infinite repeat. The SPDIF data will then be self similar on a length of 44100 and synchronization is no longer necessary. Comparing a stream of symbols on the bit by bit level should be easy.
Hi Scott,
You're going to hurt your old noodle thinking this stuff up. If you can get to C2 TP, just monitor it. A good frequency counter in add the pulses mode might give you an idea of what's going on and when. The early CD players did have that as a test point.
Having said this, a lot depends on the player. Not only mechanism quality, but it's state of calibration and wear. The new machines use servos for the adjustments. So they have some additional things to look out for.
Best, Chris
You're going to hurt your old noodle thinking this stuff up. If you can get to C2 TP, just monitor it. A good frequency counter in add the pulses mode might give you an idea of what's going on and when. The early CD players did have that as a test point.
Having said this, a lot depends on the player. Not only mechanism quality, but it's state of calibration and wear. The new machines use servos for the adjustments. So they have some additional things to look out for.
Best, Chris
Sounds like an engineer talking. In Radiation Oncology, we always did something called end-to-end testing. That's because if we miss something along the way that was completely unexpected and theoretically couldn't happen, people would die. And sometimes we found stuff that was unexpected, although not usually. Still had to do it, and do it multiple times to build confidence the 1st time wasn't a fluke.
Not easy, but not too hard if you're clever.
I've done it, with noise, sine waves and music. And I keep saying that any of you can do it to. But (almost) no one cares.
The software is fee or trial, the hardware isn't expensive (SPDIF input card).
It just takes a bit of care and time.
While Sony and Philips are still successful (even today you have to sign a NDA) to prevent their books from being freely availible, there is the free ECMA-130.
Or as Philips licensing puts so nicely, ECMA-130 approximates the yellow book. 🙂
Unfortunately i still haven´t really understand for which numbers you are looking.
Is it something like the ideal situation, starting with a nearly error free disc and looking what happens down the transmission path?
Or, do you want to know what happens in reality (means everyday life) where discs got scratches, fingerprints, temperature cycles, are eccentric and are played with disc mechanisms slightly deadjusted?
One of the key factors is the term "experienced listener" as that usually means, people listening to various music daily over extended time periods in a professional way. And even for those, see for example the ITU-R BS.1116-x, intensive training under the specific test conditions and with the specific EUT is recommended.
As there is no magic to "ABX" any experimenter should carefully think about the test protocol to use. At the beginning you must have clear hypothesises that will be tested. And then work your way down til the specific conditions are fixed.
As you have said the last time, positive and negative controls are mandatory, but we all know that in the audio field test with these controls are quite rare.
Clearly written hypothesis are quite rare too.
You missed my point. If you read reviews, then people indicate that there are changes that are more likely to be down to frequency errors or crosstalk changes, which errors on the digital side cannot cause. Pathologically bad DACs such as the AudioNote maybe, but anything normal it just can't happen. Really bad jitter is audible (orders of magnitude above reality and created in DAC not in the transport). But I can't see how a transport can change soundstaging or presentation.
"Orders of magnitude above reality" is something we put already to rest the last time (a couple of months ago). Audibility is hard to evaluate from numbers as it depends on the spectrum too, but listeners might be able to detect "jitter" around or even below 1ns and cd players and transports sometimes had measured "jitter" even above that.
A DAC may create jitter by itself, but every device has a so called jitter transfer characteristics which means handles incoming jitter in different ways.
Putzeys and Grimm think that especially soundstaging could be influenced by even low frequency jitter (usually called "wander" ).....
I don't think I missed your point. The whole sequence I described was to either find out what people report hearing, or prove to their satisfaction that there is no difference. Either find the cause of the complaint, or have the complaint retracted. I did leave out some details, since they would depend on what was found along the way.
As far as people suggesting reasons for their complaints, they think they hear something and are searching for any explanation that could account for what they hear. If they are convinced some simple explanations are unlikely, or get a lot of push-back from engineering types, then they will consider more obscure mechanisms that engineers have more trouble refuting.
Maybe I'm not being clear. I worked a a field where people where dying, and to try to save them we were going to kill just part of them using lethal force capable of doing more than just killing one part of them. Failure to resolve a real problem or a merely perceived problem was simply unacceptable. Some of the problems were very difficult with no way to measure the exact cause. In some cases, the problems or perceived problems required cross-disciplinary approaches. Sometimes it required a mix of various engineering areas along with some human psychology. (Human factors are always in issue anyway.) In the case of disk drives sounding different, we may not have a good way to measure our way out of the problem with electronic instrumentation. Consider if you needed to find bombs or something, and all you found that worked were bomb sniffing dogs. If you have to find the bombs, you use what you have. There is no other choice. For CD drives, if only humans seem to be able to hear the problem, you may have to recruit one or more humans to serve as test instruments, albeit not highly reliable ones, and just deal with the complications that presents. For that you will need to gain some cooperation. This is where part of the psychology comes in. Trust me, I have had to do this kind of stuff at times, and so far I always found the problem and fixed it or got the complaint retracted. Doesn't mean I won't fail on the next one, of course. Now, there is a price to pay for this, and for a long time I thought there wasn't. My health started to decline and finally got so bad I had to retire. Very slowly my health is getting better, and only now it seems more evident that work stress was a very substantial part of my own problems.
Mark, that sounds like a very rough job to be in. Not sure I could do that kind of thing even for a day, and to say it is stressful is probably the understatement of the century!
But, back to audio. Of course we are all curios about causes of differences etc. But wouldn't be the first order of day to somehow determine that yes there is indeed a difference, repeatable and all that.
Depending on the outcome we can formulate a plan of attack. I mean, if the outcome is yes, there is a difference, we would set up a tech investigation to find the possible cause(s). If the outcome is no, there isn't a difference, the follow-up action would be very different.
At any rate, the expectation that people would change their opinion whatever the outcome, is quite optimistic, rather unrealistic!
Jan
But, back to audio. Of course we are all curios about causes of differences etc. But wouldn't be the first order of day to somehow determine that yes there is indeed a difference, repeatable and all that.
Depending on the outcome we can formulate a plan of attack. I mean, if the outcome is yes, there is a difference, we would set up a tech investigation to find the possible cause(s). If the outcome is no, there isn't a difference, the follow-up action would be very different.
At any rate, the expectation that people would change their opinion whatever the outcome, is quite optimistic, rather unrealistic!
Jan
Cyrus CD t review | What Hi-Fi?
This is a transport review. It won an award for best £500 transport.
How can a transport affect the soundstage? they liked the signature version even more Cyrus CD Xt Signature review | What Hi-Fi?.
I fully undestand the stress of mission critical design. I once wanted to go into medical stuff before my career took a different turn. But I realised that I might not have the right temperament for it.
Rats are really good at bomb finding BTW. Amazing but true 🙂
This is a transport review. It won an award for best £500 transport.
How can a transport affect the soundstage? they liked the signature version even more Cyrus CD Xt Signature review | What Hi-Fi?.
I fully undestand the stress of mission critical design. I once wanted to go into medical stuff before my career took a different turn. But I realised that I might not have the right temperament for it.
Rats are really good at bomb finding BTW. Amazing but true 🙂
A good dac receiver will remove transport jitter. I thought we had put that to bed?
Not like you to put forward an untested 'belief'. Bruno is a great engineer but also a good marketer. He is also good at hiding which he is at any point. I would welcome some testing of this belief but have not seen any.
Down to what freq is the room practically anechoic?
Running the same tests in an ordinary listening room and showing the results in pairs will be particularly illuminating.
After all, the strong design feature of this loudspeaker is to minimize the speaker-room LF interaction effects.
I can understand this.🙂
Tell that to a woman and you will see pity in her eyes ( “Ts, ts…How these poor creatures still manage to survive!”)
We are not ‘multitasking compatible’.😀
George
Could only find this... but it was a breif search.
http://www.grimmaudio.com/site/assets/files/1088/clock_jitter_spec-1.pdf
Found this as well, interesting read...
http://www.hypex.nl/docs/papers/AES123BP.pdf
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