[PhonoPhi]

It seems you have an assumption that incandescent lamps produce a buzzing noise....and are asking this community why...

Those light bulbs happened to became a deeply revealing contest of characteristic responses in this thread, i.e. personal vs. content vs. reading previous comments before replying.
In an anecdotal sense "deeply screwing that proverbial light bulb" (penetrating pun intended). Thank you for your duly contribution.

... I don’t think phonophi has any idea what the numbers represent, so he’s putting undue emphasis on things that don’t matter.

Before replying, I thought about Sibelius records of Kajanus, opinionatedly great comments about classical music... Heck, yeah, I could read the dB table but... could not get the numbers - a glass of merlot for you!

 

[PhonoPhi]

No that’s NOT the similarity! We don’t dismiss cable claims only on the basis that they’re not factually supported but on the basis that they contradict scientific theory AND directly contradict both countless objective scientific measurements and numerous well controlled double blind tests AND, on top of all that, the claims are unsupported!

And again, the bulb was an analogy, analogies are rarely, if ever, perfectly accurate, they’re just a means of illustration rather than objective claims of fact.


No, I’m not referring to dimmers, some of which are very obviously audible and probably go up to 50dBSPL or so. I was referring to just the bulbs themselves. And, there most certainly is an “accepted scenario” in which a 100w incandescent bulb would generate noise, in fact, according to the science, it’s unavoidable. Nyquist/Johnson noise, also called Thermal noise, is present in all electrical circuits and increases with temperature. Thermal noise is commonly the limiting factor of DACs even at room temperature and obviously a 100w incandescent bulb gets very much hotter. So 10dBSPL is certainly a believable figure even though it may (or may not) be incorrect.

G

Here we are talking science, but you are trying to equate a thermal (or fluctuation) noise in the electronic cicuitry and audible signal (identified as a noise) - different things.
I originally thought that the audible signal of incandescent bulbs could be due to AC, but did not find any confirmation for this hypothesis.
The transduction mechanism would be very interesting to understand, that is again why I asked this question - out of curiosity, without any "pun intended".

 

[bigshot]

According to phonofi, we’re supposed to assume that his theory is correct, even if it goes against objective tests and measurements, and against scientific theory. We have to join his upside down world if we want to understand what he’s saying. I’m not rushing to join him on that, I’m afraid.

I think at this point he’s just talking to hear himself talk. I guess he gets some kind of thrill running us around in circles. Again, I’m going to sit that dance out.

 

[PhonoPhi]

According to phonofi, we’re supposed to assume that his theory is correct, even if it goes against objective tests and measurements, and against scientific theory. We have to join his upside down world if we want to understand what he’s saying. I’m not rushing to join him on that, I’m afraid.

That is a good universal "anti-troll" speech (can be also used "anticommunist" or in support of "green energy" agenda, etc) that we could read ad nauseam in the science forum here....

I do dare to ask you - what is exactly "my theory", so I could try to understand better what you think.

 

[bigshot]

You don’t have a theory. You’re just talking to try to be a peer discussion a subject you don’t really understand, and you won’t lower yourself to humbling yourself enough to learn from the people around you. You see that as weakness I guess.

 

[gregorio]

The transduction mechanism would be very interesting to understand, that is again why I asked this question - out of curiosity, without any "pun intended".

I have no idea, maybe you should start a thread about it rather than going off-topic with this one? Although I’m not sure anyone in SS will be able to answer it.

I do dare to ask you - what is exactly "my theory", so I could try to understand better what you think.

You stated this: “Accepting the notion that most audiophile DAPs and DACs (with some amps) are coloured as a one of the working hypotheses could be really helpful for the discussion, in my opinion.” - Why would we accept that as a working hypothesis? It’s not as if we don’t already have plenty of data, countless measurements over many decades for example or a proven/demonstrated scientific explanation of what’s going on, that already disproves your hypothesis.

G

 

[bigshot]

^ this

 

[PhonoPhi]

You don’t have a theory. You’re just talking to try to be a peer discussion a subject you don’t really understand, and you won’t lower yourself to humbling yourself enough to learn from the people around you. You see that as weakness I guess.

I have no idea, maybe you should start a thread about it rather than going off-topic with this one? Although I’m not sure anyone in SS will be able to answer it.


You stated this: “Accepting the notion that most audiophile DAPs and DACs (with some amps) are coloured as a one of the working hypotheses could be really helpful for the discussion, in my opinion.” - Why would we accept that as a working hypothesis? It’s not as if we don’t already have plenty of data, countless measurements over many decades for example or a proven/demonstrated scientific explanation of what’s going on, that already disproves your hypothesis.

G

Do you have measurements for every "audiophile" DAC and DAP to support such strong statements?
Surely, ideally, electronic designs enable production of unexpensive "transparent" DACs. "Transparent" amps in portable devices (my sole limited interests) are already much more limited.

Instead of arguing about any ideal and general scenarios, and making bigshot unduly overexcited, let's try to get to the Apple dongle.

What are the limits of its transparency?
It won't be able to drive any IEM (transducer) perfectly (transparently), right?
How can we access and quantify these limits?

 

[gregorio]

Do you have measurements for every "audiophile" DAC and DAP to support such strong statements?

We have manufacturers specs for all of them and we have more comprehensive and independent measurements for a very large number of them.

Surely, ideally, electronic designs enable production of unexpensive "transparent" DACs.

Yes and have done for a long time.

"Transparent" amps in portable devices (my sole limited interests) are already much more limited.

But then of course that’s the amps and this thread is not about amps, it’s about DACs! But in general, amps are transparent too.

[1] What are the limits of it transparency?
[2] It won't be able to drive any IEM (transducer) perfectly (transparently), right?
How can we access and quantify these limits?

1. That’s a good question and it depends on various factors. Such as: The type and frequency distribution of the noise/distortion and the noise floor of the recording and listening environment. As a general rule of thumb though, transparency is achieved when noise/distortion artefacts are lower than about -70dB relative to peak level. Although it maybe very much less than this for some types of distortion and somewhat greater in some extreme scenarios.

2. In the (off-topic) case of amps, their performance can be affected by the load presented by HPs/IEMs but that’s an issue of the individual HPs/IEMs, which is off-topic for both DACs and amps! Someone using a HP/IEM that presents a load the amp is not designed to accommodate is user error, rather than a fault/colouration of the amp.

G

 

[bigshot]

Do you have measurements for every "audiophile" DAC and DAP to support such strong statements?

Do you have measurements for a single current DAC or DAP that isn’t transparent?

If a DAC or DAP isn’t transparent, it wouldn’t be converting digital signals to spec. How well do you suppose that would go over in their advertising?

DACs and DAPs are designed to be transparent. If they aren’t, they must be broken.

 

[hakunamakaka]

 

[PhonoPhi]

Do you have measurements for a single current DAC or DAP that isn’t transparent?

If a DAC or DAP isn’t transparent, it wouldn’t be converting digital signals to spec. How well do you suppose that would go over in their advertising?

DACs and DAPs are designed to be transparent. If they aren’t, they must be broken.

If you can listen and support the dialog, I can tell that

1) I would be interested to know how to measure, as I stated.
2) Surely, I have several USB DACs that colour the sound by some DSP, etc. I can name them, if you are curious,
3) I am perplexed that it is hard to grasp that at least "audiophile" products are designed and produced to sound differently (imagine if Hollywood produces the very same love story --would there be any sales, sorry for an oversimplified analogy).

Now, the question is how to distinguish and quantify this "colouring", and starting with the Apple dongle may help.

We have manufacturers specs for all of them and we have more comprehensive and independent measurements for a very large number of them.

Yes and have done for a long time.

But then of course that’s the amps and this thread is not about amps, it’s about DACs! But in general, amps are transparent too.

1. That’s a good question and it depends on various factors. Such as: The type and frequency distribution of the noise/distortion and the noise floor of the recording and listening environment. As a general rule of thumb though, transparency is achieved when noise/distortion artefacts are lower than about -70dB relative to peak level. Although it maybe very much less than this for some types of distortion and somewhat greater in some extreme scenarios.

2. In the (off-topic) case of amps, their performance can be affected by the load presented by HPs/IEMs but that’s an issue of the individual HPs/IEMs, which is off-topic for both DACs and amps! Someone using a HP/IEM that presents a load the amp is not designed to accommodate is user error, rather than a fault/colouration of the amp.

G

A good point about recordings, we can assume them to be as perfect (for the noise) and as demanding for the frequency range and dynamic range; as well as assuming "perfect ears".

My question again is how to gauge, test, measure "transparency" or deviations from transparency.

For the Apple dongle, can we estimate the range of the load impedance that should work (I could not find these typical specs for instance) and go from there.
If transducer parameters is "off topic" - what we would have to discuss - to drive an ideal load, it is much easier to be "perfect" or "transparent".

 

[bigshot]

We already went over a lot of this.

 

[PhonoPhi]

We already went over a lot of this.

I am not sure what, how and where you "went over a lot of this".

If you have the numbers for the Apple dongle - that would be great to know and use for me and hopefully many other people.

 

[gregorio]

1) I would be interested to know how to measure, as I stated.

I already mentioned the null test.

2) Surely, I have several USB DACs that colour the sound by some DSP, etc. I can name them, if you are curious,

Sure, there maybe some DACs out there that incorporate some DSP functionality besides their actual task of converting a digital signal to analogue. Obviously though that is some other functionality and it should be bypassed or set to flat if you’re testing the actual DAC.

Amps, IEMs and now digital EQ, you want to prove your false theory about DACs by discussing everything that could be involved in an audio reproduction chain EXCEPT the actual DACs you’re theorising about?

3) I am perplexed that it is hard to grasp that at least "audiophile" products are designed and produced to sound differently (imagine if Hollywood produces the very same love story --would there be any sales, sorry for an oversimplified analogy).

Yes, there are many audiophile, pro-audio and consumer products specifically designed to sound different, an EQ/tone control being an obvious example. A DAC on the other hand is designed to accurately convert a digital signal into an analogue one, hence why it’s called a DAC. How is it that this simple and obvious statement perplexes you so?

Now, the question is how to distinguish and quantify this "colouring", and starting with the Apple dongle may help.

You mean that’s your question, not “the” question because that question was answered many decades ago. In fact, we even developed the tools to manipulate this “colouring” around 80 years ago. And, we can quantify it by measuring deviations from a flat/linear response.

I’m not sure how starting with an Apple dongle helps. Maybe understanding what a tone control does would be a better place to start but if you want the measurements of an Apple dongle you’ll find them here, knock yourself out:

https://www.kenrockwell.com/apple/lightning-adapter-audio-quality.htm

G