R/E/P Community

Please login or register.

Login with username, password and session length
Advanced search  

Pages: 1 ... 9 10 [11] 12 13 ... 15   Go Down

Author Topic: Proper word clock implementation  (Read 160135 times)

bobkatz

  • Hero Member
  • *****
  • Offline Offline
  • Posts: 2926
Re: Proper word clock implementation
« Reply #150 on: December 31, 2004, 06:03:53 PM »

danlavry wrote on Fri, 31 December 2004 16:24



Due to an outpouring of an amazing number of intelligent people, I will be a permanent moderator on this site.





Congratulations, Dan! You are an incredible resource. Leshona tova et al.


BK
Logged
There are two kinds of fools,
One says-this is old and therefore good.
The other says-this is new and therefore better."

No trees were killed in the sending of this message. However a large number of
electrons were terribly inconvenienced.

Bob Olhsson

  • Hero Member
  • *****
  • Offline Offline
  • Posts: 3968
Re: Proper word clock implementation
« Reply #151 on: December 31, 2004, 08:06:37 PM »

That's great news!

jfrigo

  • Hero Member
  • *****
  • Offline Offline
  • Posts: 1029
Re: Proper word clock implementation
« Reply #152 on: January 01, 2005, 03:36:19 AM »

We're fortunate to have you as a resource here, Dan. Glad you'll be sticking around.
Logged

Nika Aldrich

  • Hero Member
  • *****
  • Offline Offline
  • Posts: 832
Re: Proper word clock implementation
« Reply #153 on: January 01, 2005, 03:41:35 AM »

danlavry wrote on Fri, 31 December 2004 16:24

Nika Aldrich wrote on Fri, 31 December 2004 16:45

Guys,
.... it appears we are clearing up a lot of miscommunication and opportunity for further miscommunication.  Because it appears that this forum is going to be turned off in the next 24 hours...Thanks to all that participated and thanks to all that worked to encourage cooler heads to prevail.
Nika


Nika,

I am sorry to see that you are back disseminating misinformation again. Due to an outpouring of an amazing number of intelligent people, I will be a permanent moderator on this site.

Dan Lavry



Well that just tells you how fast the industry changes!  My 11 day old information is apparently no longer valid after coming back from vacation.  It's great to have you as a resource and as a permanent moderator.  I'll see you in your permanent forum.

Sorry for the misinformation!

Nika
Logged
"Digital Audio Explained" now available on sale.

Click above for sample chapter, table of contents, and more.

danlavry

  • Hero Member
  • *****
  • Offline Offline
  • Posts: 997
Re: Proper word clock implementation
« Reply #154 on: January 01, 2005, 07:32:23 PM »

Lucas van der Mee wrote on Mon, 27 December 2004 18:40

Bob and Dan,

You are both “interpreting” our words...We haven’t claimed anything else...."Lucas van der Mee
Sr. Design Engineer
Apogee Electronics



Lucas,
Once again, no technical comments about the clock, instead you posted a denial.
Regarding your first point:

“l. The Big Ben is an excellent low jitter solution if you need a master clock.”

Your literature makes people think they do need one when they don’t. But aside from that I am reminded of a scene from Monty Python. A knight on the ground with limbs cut off from a battle, lay there still cajoling the other guy present to come and fight.  Here you are after all that has transpired, still trying to sell your clock on a forum dedicated to engineering issues.

Your second statement
“2. If you have to clock to a very jittery source, you’ll get better results most of the time by having the Big Ben cleaning it up first.”

How much is “very”. Also This statement hedges your previous statements.

NEXT:
“We have not CLAIMED that this is due to an external clock lowering the jitter. This is your own presumption and it is wrong.”

If I state that a door is painted white, and you say I am wrong, you are in fact saying the door is NOT painted white without having to say the words. (The door is not painted white.) On Oct, 27, 04 an Apogee rep came here taking issue with my statement that the best method to achieve lower AD jitter is to use a good internal crystal whenever possible instead of an external clock (See my previous postings)

You did, in fact, take a stand that was OPPOSITE of what you are now saying. Regarding your current sentence,

ALSO 2: "We haven’t claimed anything else.”

OK. Yes, “Let’s get it straight”. Apogee is not claiming that Big Ben will improve ADs as a clock source, compared to using AD under internal crystal operation!! It does not claim to clean jitter when used as a master clock.. Only when it resends a “very jittery source.”

AND AGAIN Your back door insult to me. “but unlike Dan I do not say: “that cannot be”. I do trust the critical thinking and listening of my customers and investigated the results.”

What results? Researched It? How investigated? What measurements? Graphs? Published where? We are not about listening tests here. But then again, I previously STATED why you could not publish results. Your claim to impact the sound ahead is an impossibility. I can investigate how I can fly like a bird. A gullible person may confuse investigation with actual results coming from an investigation.

So Lucas, what do you say to all the people that interpreted your “A Cure For the Jitters” coupled with the claims of sonic improvements of ADs when driven by Big Ben as a master clock (You do not claim it any more) as a sure way to enhance conversion (relative to internal clocking?) Do you take no responsibility for it? Do you blame the dealers?

Apogee has done an excellent job of overstating the ability of this piece of gear. Your company’s marketing line, “A Cure for the Jitters” coupled with claims of sonic improvements when the clock is used as a master clock, is at best misleading. Many do not understand the many types of jitter created during recording and transmission, where the problems are and are not and what the remedies are.

It has been my goal on this thread to try and enlighten people about the clocking concept and to raise the level of understanding. You could have help the enlightenment process. Instead we get hype and “leaders with 21st century (secret) technology". And yes, taking a cheap shot by calling me an old 20th century theoretical guy. Well you are way out of your league.

The company you work for has gone a long way with advertising and a reputation made on the quality of my designs now called “legendary and legacy” on the Apogee website. I am the authority on jitter and have been in this business from tubes to ICs. Leave the lame statements home and send the measurement results with a clear description of the test setup.

Dan Lavry
www.lavryengineering.com





Logged

ammitsboel

  • Hero Member
  • *****
  • Offline Offline
  • Posts: 1300
Re: Proper word clock implementation
« Reply #155 on: January 01, 2005, 09:15:21 PM »

bobkatz wrote on Fri, 24 December 2004 03:46

A client changed his analog mixdown from direct into a Masterlink using its converters to a high end external converter running at 2496. The sound quality of his mixes went up tremendously. I say, don't scrimp on converters!

BK


OK... so running 2496 increases sound quality?

Sorry to interrupt, but this is just wrong.


Best regards
Logged
"The male brain is designed for ecstasy" -Dr. Harvey "Gizmo" Rosenberg

bobkatz

  • Hero Member
  • *****
  • Offline Offline
  • Posts: 2926
Re: Proper word clock implementation
« Reply #156 on: January 01, 2005, 10:09:05 PM »

ammitsboel wrote on Sat, 01 January 2005 21:15

bobkatz wrote on Fri, 24 December 2004 03:46

A client changed his analog mixdown from direct into a Masterlink using its converters to a high end external converter running at 2496. The sound quality of his mixes went up tremendously. I say, don't scrimp on converters!

BK


OK... so running 2496 increases sound quality?

Sorry to interrupt, but this is just wrong.


Best regards




I'm so impressed by your deductive abilities, Henrik. The high quality external converter beat the quality of the internal converter of the Masterlink, at any sample rate, actually.
Logged
There are two kinds of fools,
One says-this is old and therefore good.
The other says-this is new and therefore better."

No trees were killed in the sending of this message. However a large number of
electrons were terribly inconvenienced.

ammitsboel

  • Hero Member
  • *****
  • Offline Offline
  • Posts: 1300
Re: Proper word clock implementation
« Reply #157 on: January 02, 2005, 07:05:27 PM »

bobkatz wrote on Sun, 02 January 2005 03:09

ammitsboel wrote on Sat, 01 January 2005 21:15

bobkatz wrote on Fri, 24 December 2004 03:46

A client changed his analog mixdown from direct into a Masterlink using its converters to a high end external converter running at 2496. The sound quality of his mixes went up tremendously. I say, don't scrimp on converters!

BK


OK... so running 2496 increases sound quality?

Sorry to interrupt, but this is just wrong.


Best regards




I'm so impressed by your deductive abilities, Henrik. The high quality external converter beat the quality of the internal converter of the Masterlink, at any sample rate, actually.


OK, now that cleared it all up Smile
Since you have had experience with the Masterlink, do you consider the internal converters better or perhaps equal to the ones in the panasonic DAT machines(when comparing in 16/44.1)?

Let's keep the deduction discussion out of this thread... although I would love to pick back at your deduction scheme some other time Smile

Best Regards  
Logged
"The male brain is designed for ecstasy" -Dr. Harvey "Gizmo" Rosenberg

bobkatz

  • Hero Member
  • *****
  • Offline Offline
  • Posts: 2926
Re: Proper word clock implementation
« Reply #158 on: February 20, 2005, 04:35:30 PM »

[quote title=ammitsboel wrote on Sun, 02 January 2005 19:05][quote title=bobkatz wrote on Sun, 02 January 2005 03:09]
ammitsboel wrote on Sat, 01 January 2005 21:15

bobkatz wrote on Fri, 24 December 2004 03:46

A client changed his analog mixdown from direct into a Masterlink using its converters to a high end external converter running at 2496. The sound quality of his mixes went up tremendously. I say, don't scrimp on converters!

BK


OK, now that cleared it all up Smile
Since you have had experience with the Masterlink, do you consider the internal converters better or perhaps equal to the ones in the panasonic DAT machines(when comparing in 16/44.1)?




Actually I was pretty impressed by the converters in the Masterlink. A bit grainy, a tetch bright, but not bad at all for an in the box converter. But there are of course better outboard units and when my client, who had been recording 9624 into the Masterlink converters, "converted" to the Benchmark A/D the sound became, well, better!

It's been too many years since i listened to a Pana DAT machine converter. But things have advanced tremendously in the converter ballpark for me to believe the Masterlink is anything but way superior to a Pana converter.

Another "in the box" converter that is way better than its price and price/performance ratio is very high, is the A/D in the Waves L2. Very nicely done. An A external converter, for sure. Leaving only room for the A plus external boxes.
Logged
There are two kinds of fools,
One says-this is old and therefore good.
The other says-this is new and therefore better."

No trees were killed in the sending of this message. However a large number of
electrons were terribly inconvenienced.

rsdio

  • Newbie
  • *
  • Offline Offline
  • Posts: 4
Re: Proper word clock implementation
« Reply #159 on: March 15, 2005, 04:48:54 AM »

Andy Peters wrote on Thu, 11 November 2004 17:02

Here's another example of how we can decouple clock domains.  It's the typical PCI sound card.  Standard PCI is 32 bits wide and clocked at 33 MHz.  Of course that's much much faster than Red Book audio, and is completely uncorrelated with audio.  

(Note: Contrived example not involving DMA engines!) During playback, the PC takes a buffer full of audio data from its memory and writes it as fast as possible over PCI into a FIFO on the sound card.  The PC then goes off and does something else as the sound card's "engine" reads audio data from the FIFO at a rate dictated by the sampling frequency.  The host must monitor the state of the FIFO (or wait for an interrupt); when it gets "almost empty" it bursts the next batch of data over PCI to the FIFO.

Again, as long as the buffer never completely empties, the playback engine doesn't have any problems, as its clocked by its own oscillator.  The playback engine doesn't even know that it's being fed data at a much higher speed.


Andy, you've overlooked an important difference between your computer PCI example and an outboard D/A: There is feedback in the computer, but not in the outboard D/A device.

In a computer, the disk does not read itself, nor does memory automatically transfer itself.  There is software which monitors the FIFO and accesses disk or memory on demand.  This is called a "pull" model of data flow.  It is easy to decouple the output clock in a "pull" model.

With outboard D/A, driven from a CD transport or any other digital audio source, there is no feedback.  The D/A cannot ask for data if it is starved, and missing even a single sample would be bad.  This is a "push" model.  The digital audio is sent out at the assumed clock rate.  All the D/A can do is lock to the incoming clock rate and attempt to de-jitter, or lock to its own clock and risk FIFO overflow or FIFO underflow.  Only an infinite FIFO size can correctly handle the latter, in the absence of some kind of feedback to the device sending the digital audio in the form of flow control.
Logged

crm0922

  • Sr. Member
  • ****
  • Offline Offline
  • Posts: 272
Re: Proper word clock implementation
« Reply #160 on: March 19, 2005, 02:07:42 AM »

Fascinating discussion...

Did Apogee ever *directly* answer the questions as Dan posed earlier?


Quote:

I. QUESTION: WHICH SOLUTION PROVIDES LESS JITTER AT THE AD LOCATION?

1. A REASONABLE FIXED CRYSTAL
2. BIG BEN DRIVING A CLOCK INTO A CHASSIS EQUIPPED WITH A PLL VIA A 10 FOOT CABLE?

II. QUESTION: CAN ONE EVER CANCEL OR REDUCE A RANDOM NOISE AT ONE END OF A CABLE WITHOUT KNOWING WHAT KIND OF JITTER ACTIVITY IS OCCURRING AT THE OTHER END?
(can one cancel, remove or reduce the receiver and PLL noise, some of it unknown, some totally random, by driving it with a clean low jitter clock? Driving it with any clock?)


I think it is necessary that they clear the air about these questions, as their comments in this thread, as well as those in their marketing materials, make it seem as though the answers would be in direct conflict with scientific fact.

This is, at the very least, a disservice to their customers and to potential customers.  I have a friend who just recently contacted me and suggested he might purchase a Big Ben to "improve" his RME converters.  He must have gotten the idea that the Big Ben would result in improved clocking from somewhere.

I was just hoping to see some more flame throwing, actually.

Just kidding.

Chris
Logged

jimbo-baby

  • Newbie
  • *
  • Offline Offline
  • Posts: 16
Re: Proper word clock implementation
« Reply #161 on: March 20, 2005, 07:28:27 AM »

i really feel for dan here...it's extremely moral and brave to defy the 192kHz thing as a converter designer, while it would obviously be easier and probably more profitable to "keep up with the joneses" and compete with the other manufacturers. not only that, but he'd also avoid all the hastles of arguing for hours and hours with people who know alot less than him, not only on that subject, but also on others such as this clocking one, on a forum which i'm sure he intended for technical discussion, and not the kind of bad tv soap style feuding which is going on here. i know people are entitled to their opinion but this is supposed to be a place where opinion is properly backed up. if you can't back up your statements, why argue with someone who can? i would love to see a proper reply from the apogee guy, but i've got the feeling i won't. i'd like to thank dan for being good enough to share his knowledge on this forum, and can only wish that his level of integrity would rub off on other audio designers/companies.

jimbo
Logged

crm0922

  • Sr. Member
  • ****
  • Offline Offline
  • Posts: 272
Re: Proper word clock implementation
« Reply #162 on: March 20, 2005, 03:15:06 PM »

jimbo-baby wrote on Sun, 20 March 2005 07:28

i really feel for dan here...it's extremely moral and brave to defy the 192kHz thing as a converter designer, while it would obviously be easier and probably more profitable to "keep up with the joneses" and compete with the other manufacturers. not only that, but he'd also avoid all the hastles of arguing for hours and hours with people who know alot less than him, not only on that subject, but also on others such as this clocking one, on a forum which i'm sure he intended for technical discussion, and not the kind of bad tv soap style feuding which is going on here. i know people are entitled to their opinion but this is supposed to be a place where opinion is properly backed up. if you can't back up your statements, why argue with someone who can? i would love to see a proper reply from the apogee guy, but i've got the feeling i won't. i'd like to thank dan for being good enough to share his knowledge on this forum, and can only wish that his level of integrity would rub off on other audio designers/companies.

jimbo


Agreed.  It seems that apogee spent a lot of time complaining about Dan's rhetoric and little time defending their claims here and those in their advertisements.

One of their ads has an engineer claiming the first thing you should do when you buy a DAW is add a Big Ben to improve the sound.  If this is technically impossibile, if jitter is the cause of clock-related bad sound, then that certainly seems like borderline false advertising.

I would like to see this defended if Apogee is ever to be considered a serious pro audio innovator.

Chris
Logged

Touchwood Studios

  • Jr. Member
  • **
  • Offline Offline
  • Posts: 78
Re: Proper word clock implementation
« Reply #163 on: March 21, 2005, 10:53:27 AM »


I use an external clock in my studio for clock all my different pieces together. The only differnce in what I hear is that there are no random clicks and pops (bad clocking).
Logged

Max

  • Newbie
  • *
  • Offline Offline
  • Posts: 45
Re: Proper word clock implementation
« Reply #164 on: March 21, 2005, 01:06:35 PM »

crm0922 wrote on Sun, 20 March 2005 20:15

jimbo-baby wrote on Sun, 20 March 2005 07:28

i really feel for dan here...it's extremely moral and brave to defy the 192kHz thing as a converter designer, while it would obviously be easier and probably more profitable to "keep up with the joneses" and compete with the other manufacturers. not only that, but he'd also avoid all the hastles of arguing for hours and hours with people who know alot less than him, not only on that subject, but also on others such as this clocking one, on a forum which i'm sure he intended for technical discussion, and not the kind of bad tv soap style feuding which is going on here. i know people are entitled to their opinion but this is supposed to be a place where opinion is properly backed up. if you can't back up your statements, why argue with someone who can? i would love to see a proper reply from the apogee guy, but i've got the feeling i won't. i'd like to thank dan for being good enough to share his knowledge on this forum, and can only wish that his level of integrity would rub off on other audio designers/companies.

jimbo


Agreed.  It seems that apogee spent a lot of time complaining about Dan's rhetoric and little time defending their claims here and those in their advertisements.

One of their ads has an engineer claiming the first thing you should do when you buy a DAW is add a Big Ben to improve the sound.  If this is technically impossibile, if jitter is the cause of clock-related bad sound, then that certainly seems like borderline false advertising.

I would like to see this defended if Apogee is ever to be considered a serious pro audio innovator.

Chris



If you read through the entire thread from the beginning, you will understand that this all began with some remarks about Apogee by Bob Katz in reference to some of Dan's statements. It was only after these initial disparaging remarks toward Apogee were made that we felt compelled to respond.  Our position on this has always been based on results and data compiled through listener experience and we question the rigidity of the dogma espoused here based on said experience. Dan had deleted a number of our responses in this regard, so we have opted not to continue this discussion in his forum. If you really do care about this issue and not the rhetoric being thrown around by a couple of folks with absolutely no experience on the product, do the listening.

As for the ad, understand that these are unpaid endorsements in the user's own words. Obviously, his and many other engineer's experience differs from some of the opinions on this forum, hence our comments in this very thread.

Regarding serious pro audio innovation, Apogee's record speaks for itself, and I would suggest doing a bit of research on the subject before making such statements.
Logged
Max Gutnik
Apogee Electronics
Pages: 1 ... 9 10 [11] 12 13 ... 15   Go Up
 

Site Hosted By Ashdown Technologies, Inc.

Page created in 0.026 seconds with 19 queries.