Mini Dac TDA1543 X 4 NOS - Page 54

I have been to http://mother-of-tone.com and one of the pages there, this one specifically: http://mother-of-tone.com/conversion.htm ; does a fantastic job of explaining what a "NOS" DAC (i.e. a R2R style DAC) is and does, and how it works differently and, in the opiniion of many, better (or more true to analog) than "newer" Sigma-Delta DAC designs.

 

 

That site does make the odd glaring error, so don't rely too much on it for details. The gist of it is correct though - multibit dacs (not merely R2R which are just one subset of multibit) sound more like the original than newer S-D type DACs. This is not just people's opinions, the two technologies sound different - in tonality and in dynamics.

 

From the link... "The worst sound can be achieved with 1-bit modulators, as found in DSD, respectively SACD. "

 

'ok'

Fortunately we are not partial to that on this forum...

We Dutch have a rich nautical tradition, with sayings like: "The best navigators are standing on shore." I hope you get the jist?
Edited by ]eep - 3/3/12 at 7:06am

Nope, you lost me. Send me PM if its something you'd prefer to keep off the thread.

I mean, if you're such an expert, where is your engineering diploma, website info or experience? And you are not allowed 1 mistake! If not, maybe you could consider a somewhat milder tone and less arrogance.

I do not mean you are not allowed to say anything. But please take up a more positive attitude. It is so easy to be a critic, but hard to be an artist.

I have done some reading now on the mentioned site and I must say: it is very insightfull (something wise ppl acquire after spending some time on this planet) and refreshing. Like this: messages and distortion. It seems we have a little too much distortion right over here.

Where do I say something arrogantly? Just point it out please. I do have engineering experience - if you (or anyone else for that matter) ask me about that I'll tell you. For example I managed a team of people in electronics and software design for a fairly well-known company in consumer audio for a number of years. I also have a blog - if you'd like to know the URL, just PM me and you'll get some idea of my experience in electronics if you read that. I do have an EE degree too, 1st class honours from a well-respected UK university. Does any of that help?

I don't mean to argue. I respect you. But it's the way you state things without any proof or links that kind of irritates me. Actually? No. It's not who you say you are, it's what you do. Convincing is done by reasoning.

You are talking about someone (a German dipl-ing, an education which is held in the highest esteem anywhere in the world) making 'glaring errors' without saying what they are thereby disqualifying someone you don't know anything about who has a lot more to show for himself than you (again, no disrespect towards you). I only have an ing-degree in construction (which includes acoustics btw) so I'm disqualified in this matter anyway. But I do have 30 years experience in hifi and I do know how to listen.

The HF-rolloff you speak of is totally irrelevant. 1dB is the hearing threshold for discerning sound pressure-level differences at 1000Hz , human hearing reaches to 20kHz at a young age, 15kHz at best at my age with hardly any discernment at all as to loudness at that frequency. So 3.9dB difference at 22kHz is moot. Also does no-one state anywhere how much HF-roll-off is at 20kHz (which would be the point where it starts to mean anything) or how much at the extreme of my (or your) hearing.

Look at this:

See what the dynamic range of a healthy young person is at 20kHz (20dB) compared to 1kHz (130dB)? And I'm not even talking about the range of music (orchestral range in the graph).

This is how 'linear' our hearing is! Again, this is for a young person that hasn't ruined his hearing with his ipod, headphones, concerts etc.

This is how our absolute hearing threshold changes with the years.
The Absolute Threshold of Hearing (ATH) is the volume level at which one can detect a particular sound 50% of the time. If one has a low absolute threshold, it means that he is able to detect small amounts of stimulation, and thus is more sensitive. If one has a high absolute threshold, then he requires more stimulation and thus is less sensitive.
The following are curves of the ATH for several age groups over frequency. Zwicker approximated these curves from experiments on a number of subjects:


When we speak of 20-20kHz in hifi, see how 1-dimensional this statement is? Because it is (ab)used by marketing to convince us to buy irrelevant expensive junk.
So when you speak of a high frequency roll-off of 3dB at 20kHz that is a 0-dimensional statement (not to say unsubstantiated or erroneous; it should be 3.9dB at 22kHz with no reference to how steep the roll-off is, 6? 12? 18? 24 dB/oct?).
Edited by ]eep - 3/4/12 at 10:16am

You're tilting at windmills here. I have not so far mentioned anything about roll-off at 22kHz and why would I? That in the range of ultrasonics.

 

As for the glaring errors on that website - here's one to be going on with. The writer conflates 'multi-bit DAC' with 'R2R DAC'. So then when he goes on to claim that Philips made R2R DACs, he's in error. They didn't. They made some of the best (if not the best) multibit DACs but none were R2R. Want to argue that as a fact? Here's another - he says that the PCM1704 has 'true 24 bit noise-free resolution' - the datasheet disagrees with this claim. So are we to believe BB/TI engineers or the website author?

Hi guys,

 

I agree that getting greater clarification on things, including specific specifics, is always good and helpful. I'm not necessarily sure that the author of mother-of-tone.com was necessarily aware that the Philips DACs, while multibit, weren't R2R. At any rate, the virtures of multibit DACs over Sigma Delta seem fairly clear by that article, and thats the purpose of why I posted it. Splitting hairs and fighting about things doesn't lead to greater collaboration or understanding. Now I'm not telling you what to do or what to think, I'm simply making an observation.

 

I think a lot of what both of you have posted is interesting and helpful, and good for illuminating the confusing topology of the DAC world, and appreciate it.

 

There's always going to be an assumption or an inaccuracy(ies) here or there, it doesn't have to be the end of the world.

Not that it's relevant to this thread, but I sometimes wonder how our non-linear hearing interacts with the frequency response of a linear speaker or headphone.

 

Sure, reality is linear, but mixed and synthesised composition is not.
 

THAT. = A very compelling concept.

Not to split hairs here but no, reality in general isn't linear. Linear is a special case and almost always an approximation just to make the math easier (like no longer impossible).

I mean white noise from a TV in reality is linear, but yeah it depends how far away you're standing from the TV lol.

 

Yeah and kudos to you and the writer for pointing this out. Its not so widely known and deserves more publicity that S-D converters do indeed add colouration to the sound which does not show up on their squeaky-clean FFT plots in the datasheets.