Digital Signal Transmission

[fas42]

The reason why SQ is affected is because adding something with the magical name, "isolator", is no guarantee that in fact that two areas of a system are in fact, isolated. Interference from one area can travel to another area via more than the obvious routes - and until one has confirmed that indeed there is no cross interaction, using the word "isolation" has no more meaning than the word "medicated" printed on the packaging of something bought from a pharmacy.

[fas42]

8 hours ago, TomJ said:

I once connected a power bank to the streamer and the unclean electricity from the power bank was initially interpreted positively as more space.
With the isolator between my streamer and the RME ADI 2 DAC, this effect is over. Everything that is done in front of the isolator no longer has any (audible) influence on the sound.
I'm speculating now that the alleged sound improvements are actually a deterioration due to HF interference, which, if you try out intensively, have the right dose and please. This means that local files may sound better to some, as interference from hard drives, ssd readers, etc. are interspersed, but this does not correspond to the original sound.

 

I've noted this thinking many times amongst people who don't want to appreciate what's going on - they see it as a win when the sound is dulled down to the point where changing things no longer has an impact; their listening is isolated from what's actually on the recording, and a uniformity in what they hear means there are no unexpected, unwanted surprises.

 

"More space" is precisely what's on the recording - and when it's correctly reproduced, that 'space' changes with every recording, track ... how could it not be so, since the environment of the recording space, and equipment, is so different, from one to the next?  A generally pleasant sameness may be satisfying, but is not the full story ...

 

Yes, it is irritating when "everything matters!" - but that's the story of trying to maximise accuracy of playback; sometimes, things get subjectively more sensitive to interference effects on the audio journey - but that's a positive, not a negative. If the next step is a really good one, all the positives in the SQ remain; but the interference anomalies are reduced.

[fas42]

1 hour ago, TomJ said:

 The "more space" or darker background e.g. through a special LAN cable is not available on the source, but is added incorrectly. To save myself such gambling, I am very happy with the isolator.

 

This is where people like myself disagree with you ... you believe that the 'better' presentation is just a form of distortion; whereas years of experience and investigation have convinced those like myself that in fact one is getting closer to the true nature of what has been recorded.

[fas42]

I agree with the thrust of what you're saying. If the DAC is not good enough, then one solution is to buy, a "better DAC". But IME such units are still very, very expensive - a frugal buyer's solution is to add the engineering "on the outside" for more modest cost units; but it may take good understanding what one's after, to do that successfully.

[fas42]

1 hour ago, kumakuma said:

 

A solution that only makes sense IF it is technically possible to make such modifications to the DAC AND you have the required skills and knowledge AND you have no better uses for your time.

 

Every half keen audiophile does that already - except, it's called tweaking .. remember, we're talking external stuff. Hmmm, vibration might be a problem, okay, we'll explore mounting it on different platforms; power supplies aren't good enough, okay, we'll add external mains power conditioning to compensate for the lack of internal cleaning up of such; it's sensitive to the nature and quality of input waveforms, okay, we'll condition those in myriads of ways, to address the fact that the internal engineering is not robust enough to cope with whatever comes its way ... and on it goes ...

 

If you're an audio enthusiast, you want better sound ... normally 😜. Therefore, a  good use of your time is to try things to "make it better" ...

[fas42]

Just now, TomJ said:

I agree with you regarding the analogue part of the chain. But regarding the digital side the goal must be to transport the data without any influence to the DAC. And cable-sound it sound of a router should not be the target. But I can still here slightly differences of USB cable from Isolator to the DAC. This could be because different cable handle HF and noise different. Best way would be, that the Isolator would be integrated on the board of the DAC.

 

Yes, the isolation mechanism should be part of the DAC - the concept is that the converter is able to handle any digital input which is measurably correct, even though the signal lines, waveforms are as noisy as hell, with zero audible impact. That is just good engineering, and should be the end goal.

[fas42]

12 hours ago, TomJ said:

 I think many people try to use their knowledge from the analogue domain to optimize the digital side - but these are completely different technologies.

 

The purpose of the waveforms are very different - the digital ones serve as the transport mechanism for digital data. But what we are really worried about is the integrity of the resulting, after D/A, analogue waveforms - and, unfortunately, this is highly susceptible to interference, electrical noise. Which the digital waveforms can carry in large quantities, or provoke other parts of the circuitry to effectively generate ... just saying this shouldn't happen doesn't make it so; the designer has to go to the effort of guaranteeing  that it doesn't.

 

Hence, knowledge from the analogue domain can be very, very useful - just putting things into different boxes, with "Analogue", and, "Digital", labels on them doesn't solve a thing - engineering has to get into bed with the players, and make sure that good enough isolation is in fact the case.

[fas42]

Just now, sandyk said:

 Even the use of pop rivets in the construction of a PC's metal case can cause some audible degradation,  including reduced stereo separation and a degraded sound stage, as well as a grainy background or what appears to be a veil over the sound. 

 

That's an interesting one! As compared to using what to bond the parts of the case together? And what is considered to be going on here?

[fas42]

20 minutes ago, pkane2001 said:

 

Of course! Got anything objective to back up this bold and exciting claim? I'm ready to weld if you do 🤪

 

My feeling is that the panels of the case, if metal, are not well electrically connected - if relying on pop rivets to do this, it most likely will fail; from paint, etc. If self tapping screws, which properly bit into the metal, were used, I suspect the variance would go away.

[fas42]

Just to throw into the debate about "what matters" - the low cost digital speakers I currently use, which has all the digital stuff coming in via the lowest cost optical link - now has achieved immunity, something I have never achieved before, from mains noise; to as far as I've been able to detect, subjectively. Now, I have had to put in lots and lots of time exploring this - and has required "extreme" isolating techniques.

 

This, Yet Again, emphasises how sensitive digital playback is to any noise which "shouldn't be there!" - meaning, any link which involves galvanic connection to another device which is a possible source of noise, should always be suspected - just putting up graphs which show magical competence in some parameter, which may or may not be relevant to what you hear, is not going to get you closer to a "final solution".

[fas42]

26 minutes ago, TomJ said:

But the problem then seems to be more about making the diagnosis. But how, without measurements? Seems to be a gamble.

 

Ah, good ol' measurements - if you are suffering pain, and I can't measure anything, then it must be in your head - the scientific community can't exist if this fundamental truth is not accepted, 🤪.

 

The pain of poor sounding playback will just go away if you keep studying graphs and charts of brilliant measurements, taken of your gear on the testbench ... take twice daily, or as needed. 🙂

[fas42]

15 hours ago, pkane2001 said:

 

A doctor subscribing to Frank's approach to diagnosing may not be my first choice :)

 

Me: Doctor, I've been having this cough....

Dr Frank: Let's remove your appendix, it's most often a problem in people of your age

Me: shouldn't we at least run some tests, get some lab results, an X-ray or two?

Dr Frank: No need, tests are for those other doctors that read textbooks and look at charts

Me, a week later: Doctor, my appendix was removed and yet I'm still coughing

Dr Frank: Ah, that's because you have two kidneys and they are unbalanced. We'll need to remove one.

Me, two weeks later: Doctor, I'm still recovering from the two surgeries, but my cough has not gone away

Dr Frank: It must be your heart, let's do a bypass

Me, a month later: Doctor, I'm feeling awful, I can barely move, have chest pain, and bleeding from all my incisions... but I'm still coughing

Dr Frank: I suspect it's your foot. We'll need to amputate

Me: I'd like to get a second opinion from one of those "other" doctors, if you don't mind

 

 

 

First time I've seen doing major surgery called, diagnosis - you may care to note that I always aim to do the bare minimum to the guts of whatever I deal with, to 'fix' it - with current actives, I have not even opened them up yet - no idea what it looks like inside. So, being radical in that sense is not part of the recipe, 😀.

[fas42]

3 hours ago, asdf1000 said:

 

Rob Watts talks about RF all the time for years now on Head-Fi forum. He describes it like a "fungus" that gets to all parts of a DAC. Increases IM distortion 

 

"Fungus" is a good term to use - the sense of relief when all 'fungus' is extinguished is, umm, palpable 😀 ... many people never reach this point, so don't understand what the fuss is all about ...

[fas42]

4 hours ago, pkane2001 said:

I think surgery often follows a radical diagnosis, such as excising a volume control, but I’m not a doctor ;)

 

If one is very careful not to hear differences, when some experiment is made, to test whether some factor may relevant - because to do so threatens one's carefully built up set of ideas - then most things are probably radical. If one does not suffer this affliction, then that person can determine that indeed the volume control is a weakness - then, either grin and bear it; or, do something to improve matters ... which might be to remove that part from the circuit.

[fas42]

2 hours ago, TomJ said:

If noise is the cause of all the evil and the effect cannot be measured, why is the cause not simply measured ("Noise")?

Why not stated the noise level for products done by measurements , but always only talked about sound-enhancing "Low Noise" products without giving any values?

 

Because it is hard to give meaningful measurements - its effects could be measured, but no-one has clear ideas on what precisely to measure. On the cause side, it would be possible to make all sorts of measurements of various types of noise; but actually pinning any of these measurements on what is subjectively heard would be difficult - one could wave one's hands and say that the lowest numbers are probably going to mean the best performing device; but this would just be guessing.

[fas42]

8 hours ago, pkane2001 said:

 

If one is very careful to look for objective evidence, one can avoid the influence of beliefs, ideas, charlatans, or misleading advertising copy.  This is why science was invented. It would really help if instead of claiming lots of things that you "believe you hear" you'd spend at least some of the time trying to prove it. Prove it to yourself, not to me. Claiming that you "hear it, therefore it must be so" style of discovery has gone out of favor at about Renaissance time, and for a good reason.  As illustrated in the transcript of my conversation with Dr. Frank, that approach can result in a permanent loss of major body parts ;)

 

 

 

 

Paul, Paul, Paul ... you're deep in the objectivist's whirlpool, I'm afraid ... all science has to be ultimately based on observation, of the world as it is. Anything else is just another ride of self-delusion, which may be very difficult to get off ...

 

I learnt something 3 decades ago which has been absolutely consistent, to this day. Which is, that audio playback can be immensely involving and satisfying - but that status of performance is very, very fragile; the slightest impairment, somewhere, can collapse the illusion. I can prove to myself at any time that my ideas are sound, by going and listening to a nominally high performance, well measuring setup - which is, subjectively, awful. It stinks of a distortion signature; it's flawed as a mechanism for listening to recordings.

 

The absence of those distortions is all that matters. As is the absence of pain, as a human. Much of the world operates on the basis that "this has worked as a means of solving an issue; therefore, we'll keep using it" ... if everything that didn't have the highest level of rigorous proof as being effective was ditched tomorrow, by decree - the world would be in a very, very, very bad place, very fast ...

[fas42]

9 hours ago, TomJ said:

 

I also doubt, for example, that the noise level will be lowered that much compared to a standard switch with LPS. That would be easy to prove. But I always only get the answer, I have to believe it and trust my ears.

If the producer could prove something here, they would have more customers. Do they not want this?

 

 

 

Can a doctor prove to you that the medication that he prescribes for you will solve your pain issues, by quoting what the manufacturers test results were? I'm afraid in the murky world of audio there are so many variables, that feeding you with numbers might make you feel more comfortable - but has little to do with guaranteeing outcomes.

[fas42]

Just now, pkane2001 said:

 

There's observation and there's scientific observation, Frank. What you're describing is the kind that leads to self-delusion and amputated extremities. 

 

Right, there's observation by "normal" people - and then there's observation by "scientific" people ... the latter is obviously of a far higher standard, I can tell ... 🤪.

[fas42]

2 hours ago, semente said:

Wouldn’t life be a lot easier if we weren’t able to measure a lot of stuff? And cheaper?

 

Why complicate when there’s a simplistic measure for DAC performance called SINAD which tells us all we need to know (that all DACs sound the same)? With pink panther ratings.

 

Yeeah ... measurements are an aid in some of the development of devices - but as a means of evaluating whether some setup delivers, in the areas that matter, they are close to useless ...

[fas42]

Just now, pkane2001 said:

 

Are you seriously doubting it? Give you an example:   

 

observation by "normal" people = Earth is flat (I can see this with my own eyes looking out the window)

observation by "scientific" people = Earth is a spheroid planet rotating around a star that's part of a galaxy that itself is part of a local galaxy group that's part of a universe containing billions of galaxies

 

Which one do you think is of a "higher" standard?

 

How about this ... go to a restaurant, everyone has the same meal - then it is evaluated. You have a food critic, an owner of a restaurant chain, a master chef, and a winner of the physics Nobel Prize as the group of 4 eating - whose evaluation has the greatest weight?

[fas42]

2 minutes ago, TomJ said:

My hobby is not to look at numbers - I dont wont to spend my time in testing thousands of devices in thousands of combination. and when i am done to here from someone else there is a 1001th device to test.

I want to hear music in the finest way.

Its like pkane2001 mentioned: its like in the middle age.

 

The whole thing reminds me of a story from my studies. I really wanted to use a radiosity program that was only available for linux. Since I wasn't a Linux user, I went to the Linux group at my university with the hope of getting help. But these guys weren't interested in helping me and sharing their knowledge. Instead, they felt cool to have a knowledge that others don't, so they made a big secret. I just thought "fuck you linux-nerds" and got myself a program for Windows at great expense.

 

 

Yep. With you on that one. Can't think of the word that describes that attitude - but it is infuriating.

 

There are no easy answers. Full stop. Every rig that is put together is a gamble - in that it might deliver special sound straight away, or it might not. If I had the money, and I wanted someone else to do the work, I would contract someone to assemble a rig - and they wouldn't get paid a major chunk of the money until it performed to a standard I wanted.

 

 

[fas42]

3 minutes ago, pkane2001 said:

 

Let's put it this way: I'd trust the scientist to determine if there's any poison in my meal much more than I would a master chef. 

 

Right, and here's where the scientific approach does come in - if the majority agree that there is something not quite right about the food, which is not to do with how it was handled in the kitchen, but they can't put their finger on it - then the scientific methods climb on board, and sort things out.

 

So, there are two different types of evaluation coming into play - neither is superior; both serve a necessary function.

[fas42]

7 minutes ago, pkane2001 said:

 

No. Whether or not the majority agrees, the scientist can determine if the food is poisoned. Reality is not based on a majority vote of "normal" people and certainly couldn't care less what they think of the food. It's either poisoned or it's not.

 

Okay, losing you now ... 🙂. The important thing, with the meal, is whether it was of a high standard or not. That it was poisoned is an entirely different issue.

 

The reality that mattered at the time of the eating was the quality of the experience. The only people who might be obsessed about the poisoning issue would be those food testers that dictators, etc, carry around with them 😀.

[fas42]

34 minutes ago, pkane2001 said:

What do you think distortion is? Poison! :)

 

Everything is distorted! The very best system, that even I 🤪 could dream of, has distortion - what counts is whether that distortion, poison if you want to call it that, is significant to the listening experience!

[fas42]

4 minutes ago, Confused said:

It’s always wrong to blame the meal.  Get your fork working in the right zone and your taste bud brain system will compensate for any anomalies in the food and let the true magic of the meal shine through.

 

Yes, mood plays a part. And of course, good ol' red wine climbs on board as well, 😉 ... but one can stand fully apart from the 'distortions' of mood and drugs, and decide whether the food was as prepared as well as as could be reasonably expected - in the cool light of day.

 

The meal has to stand on its own. If it has a flavour imbalance, or a mistake was made in one step, then there's no getting around this - you can try covering this up with over application of a 'tubey' sauce, say - but those who know how good the raw ingredients can come together will just be irritated by this - this is where experience comes into it, so strongly.