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Everything sounds the same


mansr

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2 hours ago, marce said:

Look at the dates, things move on...

Why do you always look for something to support the negative view, why not post some real info on how it cna be done, look for some of the positive information. Jeez if I worked like this I would never get a job done, because a lot look impossible when you start, so you don't go it can't be done, you start with reading the active devices data sheets and planning out the critical signal flows, both local to circuitry and accross the board between blocks of circuitry...

You don't look for reasons why it cant be done, that's giving in before you start.

 

2009? The latest book from the author you suggested I read, in the previous post ...

 

I was reacting to your comment that it was "well documented" - when in fact there is much material pointing out the common design errors made, and mistaken ideas clung to. IOW, it's not trivial to ensure an absolutely clean separation between the areas - and the USB link for audio seems to be a prime area for issues to arise, going by the number of, yes, negative comments about the performance of the standard design methods.

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The man has many faces.

And still that is not him.

 

 

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5 hours ago, PeterSt said:

 

The man has many faces.

And still that is not him.

 

 

A quick search would find who he is... The fact its got Ti (Texas Instruments) all over the presentation would possibly give you a hint.

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21 hours ago, fas42 said:

 

2009? The latest book from the author you suggested I read, in the previous post ...

 

I was reacting to your comment that it was "well documented" - when in fact there is much material pointing out the common design errors made, and mistaken ideas clung to. IOW, it's not trivial to ensure an absolutely clean separation between the areas - and the USB link for audio seems to be a prime area for issues to arise, going by the number of, yes, negative comments about the performance of the standard design methods.

Disagree, do this every day, just recently done two boards with microwave (analogue), 24 bit DAC's, digital and SMPS's... work perfectly, USB is a doddle by comparison... But then this is audiophile audio so normal rules don't apply...

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Just now, marce said:

But then this is audiophile audio so normal rules don't apply...

 

What could be odd without real notice at first glance, is that you'd always have two channels fighting each other (I tend to direct to possible oscillation). Besides that we usually have more than one clock domain - same thing.

 

Question about the latter (no 7500 to be earned) : how would you approach the virtually required two different oscillators for 44.1 vs 48 base ?

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XXHighEnd (developer)

Phasure NOS1 24/768 Async USB DAC (manufacturer)

Phasure Mach III Audio PC with Linear PSU (manufacturer)

Orelino & Orelo MKII Speakers (designer/supplier)

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10 hours ago, PeterSt said:

 

The man has many faces.

And still that is not him.

 

 

 

Steely Dan even wrote a song about him. 

One never knows, do one? - Fats Waller

The fairest thing we can experience is the mysterious. It is the fundamental emotion which stands at the cradle of true art and true science. - Einstein

Computer, Audirvana -> optical Ethernet to Fitlet3 -> Fibbr Alpha Optical USB -> iFi NEO iDSD DAC -> Apollon Audio 1ET400A Mini (Purifi based) -> Vandersteen 3A Signature.

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7 hours ago, PeterSt said:

 

What could be odd without real notice at first glance, is that you'd always have two channels fighting each other (I tend to direct to possible oscillation). Besides that we usually have more than one clock domain - same thing.

 

Question about the latter (no 7500 to be earned) : how would you approach the virtually required two different oscillators for 44.1 vs 48 base ?

I'd refer ti Ti and the such for options...

http://www.ti.com/lit/an/scaa088/scaa088.pdf

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9 minutes ago, PeterSt said:

 

Yes, and that wouldn't result in an audio product whatsoever. Not even back in 2008.

 

Are you suggesting that TI way “back in 2008” wasn’t interested in audio or rather that they, then, didn’t consider audio in need to high speed design techniques? 

 

9 minutes ago, PeterSt said:

Say that this shows that knowing a few things about signal integrity is only related for 50% or less to audio. The remainder plainly fails.

And no TI or AD etc. papers and articles are going to help out. Also do notice that these are commercial papers, and the first time I'd pick the referenced chip etc. from such a paper yet has to come. One can learn quite a few things from those papers, though. Especially how not to do it. But furthermore and more importantly, the data is there. So we can use those papers for hints.

 

A lot is related (indeed) to those papers being obsolete in no-time. You can already see it by datasheets coming up with new versions of them and e.g. different bypassing methods (like for OpAmps). Same chip, but new datasheet and way better application. That is audio.

 

Like for the PCM1704? Does TI have an updated data sheet?

 

 

9 minutes ago, PeterSt said:

And since there is no education for audio, "we" need to do it ourselves.

General message Never think you know a lot when you weren't there for real ...

 

 

Rather than dismiss that presentation fromTI out of hand, please point to specifics where it is so wrong.

 

TI actually has come out with a wide variety of IC directly targeted at audio, including high end — indeed you use them,  they also have a wide variety of USB IC so tell me why they wouldn’t be in the best position to know?

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27 minutes ago, jabbr said:

Are you suggesting that TI way “back in 2008” wasn’t interested in audio or rather that they, then, didn’t consider audio in need to high speed design techniques? 

 

Um ... that paper is about audio. Did you even open it ?

And next read it ? (yes you can do that in a minute or five without missing too much)

 

28 minutes ago, jabbr said:

Like for the PCM1704? Does TI have an updated data sheet?

 

Same thing or else similar. Did you read it and next did you read the specs of your Phasure DAC ?

And ? do they match somewhat ?

BBZZZZzzzzzzzz

OK ?

 

30 minutes ago, jabbr said:

please point to specifics where it is so wrong.

 

You can do it ... you can do it.

 

31 minutes ago, jabbr said:

 

TI actually has come out with a wide variety of IC directly targeted at audio, including high end

 

Hahahaha. You mean the EOL ones, right ?

So No. And No, I won't give examples either. You know it or you don't.

Hint : And again I bought those all.

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XXHighEnd (developer)

Phasure NOS1 24/768 Async USB DAC (manufacturer)

Phasure Mach III Audio PC with Linear PSU (manufacturer)

Orelino & Orelo MKII Speakers (designer/supplier)

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35 minutes ago, jabbr said:

Rather than dismiss that presentation fromTI out of hand

 

Wait again. You seem to mix up two presentations. One is a presentation and the other is a paper. I dismiss the paper.

Anything else ?

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XXHighEnd (developer)

Phasure NOS1 24/768 Async USB DAC (manufacturer)

Phasure Mach III Audio PC with Linear PSU (manufacturer)

Orelino & Orelo MKII Speakers (designer/supplier)

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Just now, jabbr said:

No you can do it, I’m not making fun of the guys name or phone number 

 

Get real. Have lunch. Whatever.

 

What's up anyway ?

Lush^3-e      Lush^2      Blaxius^2.5      Ethernet^3     HDMI^2     XLR^2

XXHighEnd (developer)

Phasure NOS1 24/768 Async USB DAC (manufacturer)

Phasure Mach III Audio PC with Linear PSU (manufacturer)

Orelino & Orelo MKII Speakers (designer/supplier)

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Just now, mansr said:

@PeterSt Please stop fucking up my thread.

 

Fucking threads can be fucked.

I have fun with it.

 

You don't understand it either ? not unexpected.

 

If you have nothing serious to do, start laying out where it went wrong. I'll read about it tomorrow. Thanks.

 

Lush^3-e      Lush^2      Blaxius^2.5      Ethernet^3     HDMI^2     XLR^2

XXHighEnd (developer)

Phasure NOS1 24/768 Async USB DAC (manufacturer)

Phasure Mach III Audio PC with Linear PSU (manufacturer)

Orelino & Orelo MKII Speakers (designer/supplier)

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1 hour ago, marce said:

I'd refer ti Ti and the such for options...

http://www.ti.com/lit/an/scaa088/scaa088.pdf

 

This is how I’d criticize this paper:

 

While this technique is one of several that can be used, the close-in phase error at 60-70 dB/Hz @ 100Hz is not close to the best than can be obtained eg 90-120 @ 1Hz ... a lower phase error technique is to use knowledge of which clock family is to be used — which is obtained from the USB driver — and directly select the correct clock family and integer divisor

 

?‍♂️

 

Nothing personal

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