External Clocking - is it all that?

madtheory wrote: »

Ya, but the master is always the internal oscillator.


All the Digi HD stuff And pretty much any converter built since around 2004, give or take.

I can't keep up with the rate of posting and editing!

Bob Katz's book is a little out of date on the issue, I haven't seen the revised edition so I dunno what he says about it in that. Given the omnipresence of PLLs, I'd say that no current firewire box takes its clock ref off the firewire bus.

Note that Dan Lavry has had some very heated arguments with Apogee folk online, about their claims for their cables and their clocks. Funnily enough, it was always Mr.Lavry that had the science argument, and Apogee the subjective line...

Jesus we are posting at a ridiculous rate:D. If you are correct and that all HD stuff has these converters, then you will have an interesting day when you hook up an external clock to this. According to your theory there should be no difference, correct? We'll wait and see, for you to post back with your opinions.

I agree the Bob Katz book is probably outdated now with the rate of technology.

I am not a techie but your opinion seems to suggest that all converters in audio equipment these days more or less is jitter free. I'd love if that was the case.:p

Could you post a link to the Dan Lavry/Apogee debate

teamdresch wrote: »

I believe the line is that a converter should have less jitter when clocked internally than when an external clock is used, not that PLL means no jitter.

Good point. I still hold to my own experience of Protools HD, which according
to madtheory has PLL converters, It sounds markedly better when clocked to an external clock.

All of this depends on the quality of your clock source and that if the external one is more solid than the internal one it surely must be better.

We await madtheory's test.:eek:

Christ! The posting rate is phenomenal.

PaulBrewer wrote: »

But if the clock it re-clocks to has less jitter does that get lost in the process? Is that the central point of your argument?

Pretty much, but with PLL the rule is, internal is always better. I'll dig out links to Lavry's white paper, and the Apogee debacle...

Paul, can you email me when your demo Big Ben is back in the shop?

madtheory wrote: »

Christ! The posting rate is phenomenal.

Pretty much, but with PLL the rule is, internal is always better. I'll dig out links to Lavry's white paper, and the Apogee debacle...

Paul, can you email me when your demo Big Ben is back in the shop?

Interesting.

If my understanding of the science presented here is correct, as WD says there should be NO perceivable sonic difference with or without an external wordclock.

Can we agree that if there's an perceivable repeatable difference in sound then the science itself isn't explaining what is happening?


Is that what we're talking about?

We'll leave the 'Better' argument for another day !

woodsdenis wrote: »

I am totally prepared to accept aswell that the converters in PTHD are not up to scratch.:o

Ya, that's a distinct possibility Blind AB test with a few heads will sort this out I think...

SO it seems that a genuine blind AB test is impossible, which is why this is always a contentious point. Dandan has come up with an interesting workaround, so we'll try it and see what the result is.

Emailing the other lads, they're all of the view that external clock is BS

madtheory wrote: »

SO it seems that a genuine blind AB test is impossible, which is why this is always a contentious point. Dandan has come up with an interesting workaround, so we'll try it and see what the result is.

Emailing the other lads, they're all of the view that external clock is BS

Who are the other lads?

Why would professionals buy a product if it's not needed or doesn't add something to your product? Especially given the cost.

I'd be very surprised if the test results proved the pros wrong.

But it will be interesting to see the results none the less.

PaulBrewer wrote: »

Well you may ask - however the fact they do doesn't mean , by itself, that it's better.

Anyways, MadTheory has put himself under pressure to prove his point now .... if anyone of his party can hear any difference with the Big Ben he owes me big time.

Very true, Flies and Sh1t3, suddenly springs to mind.

.... but he also says

"I am no fan of distribution amplifiers either. You can not beat:
Driver to point A (with a BNC T), than to point B (with BNC T)… at the end the BNC T is terminated with the proper line impedance (if the cable is 75Ohm, so is the termination). It is a cost effective solution that yields the best results."

woodsdenis wrote: »

I think the answer to this is simple. If you are using hi grade converters the
difference will be minimal if any. If you are using PTHD like me the difference is a lot more noticeable. Digidesign HD interfaces are by no means terrible,
but not stellar either. HD is way better than the previous incarnations.

I hope that madtheory takes the time to investigate this. If all the testers
think that External Clocking is BS then the result maybe skewed.

I can only speak for my system. Yours will no doubt be different. Try it out.
If it doesn't float your boat spend your money on loads of other gear.:D

Maybe that's just it.

It's mostly Digi 192 owners I've supplied Big Bens to.

The most interesting thing to me is the looping the clock with T Connectors as was suggested by a previous poster.

I'll do some experimenting there.
Dan and Bob make the points you have to be sure of your termination processes.

madtheory wrote: »

I've two others on board, who are also electronics engineers. Should be able to get a few more too. I've also just figured out a neat way to do a blind AB test. So we won't know which clock we're hearing. The room has a very low noise floor, and is pretty flat (for a room). I'll write up a full report Paul, you'll know who's involved.

I would hope there would be a few Audio engineers too;)

MT I am trawling my way through the thread. Very interesting stuff. Did you see the thread on Dan Lavry own forum where he is accused of altering/deleting responses by Apogee :eek: I thought things got out of hand here.

Another Bob Katz quote

Dan is saying that, "all other things being equal, in a well-designed converter, internal clock will always perform better than, or equal to an external clock."

You have to prove whether the Apogee is a well-designed converter! If it's a poor converter, it may very well perform better on external clock. A left-handed "compliment" if I ever saw one!

And yes, everyone is clueless... very very few people have grasped the implications of what Dan has to say. John Watkinson, among many other competent writers, myself included, have been haranguing this topic for a long time. Manufacturers, it seems are the most clueless.

Doesn't mince his words does he.

Seziertisch wrote: »

The moral of the story is that if someone offers you the choice between a Big Ben and an API desk, go for the desk.

That said, in my experience in a more modest recording set up better converters do make quite a difference.

I'd go for the desk too !
But I have the money to buy a Ben ....

Good morning Dennis,

Two of the guys are audio engineers who studied electronics, like myself. That's why we're very sceptical about external clock. But we will be doing a blind AB test, so our bias is eliminated from the test

Ya, that Apogee thread got well out of hand. I think Dan is your typical engineer, not good at selling/ charming people. I would say he's the world's leading audio converter designer- if NASA trusted him, then I do

When you said "Apogee converter" you meant the 192, right?

Paul, I still think that the price of the Big Ben is better spent on acoustic treatment. If you feel it's the last thing in your system that needs to be improved, and you already own an original C12, then perhaps you should spend the cash on a trip to Fez instead?

How much is the Big Ben anyway? Wouldn't it be better to buy a Lavry or a Prism converter to replace the 192?