*Clocking Master - Converter Internal vs Synchronizers

[Ben B]

There is a lot of technical literature that supports the idea that external clocking can never improve the performance of a converter compared to clocking internally (unless said converter is broken). Having read the explanations, I believe it. Master word clock generators can be convenient when syncing multiple digital audio devices together, but whenever possible I go for internal clocking.

[Bassmankr]

Concensus here at this point in time is that your main - best A/D converter's internal clock should be master. Some epic threads can be found on this subject with a simple search. Given how easy it is to try out different master / slave clocking configurations it's still just a good idea to use your ears with what you have available and get your hands dirty testing. I'd go slow and audition first if you are thinking of buying an external clock bearing in mind placebo effects and expectation bias (try to listen with a blind test). Comparing a live source through your monitering chain compared to the same after A/D - D/A conversions is also good procedure. Some other owners of your particular Lynx converters also say they sound better at 88.2k - 96k sample rate with more threads regarding that here.

[Ben B]

Originally Posted by GaryWeinrib

that's not true in all cases

Care to elaborate on your point?

[Ben B]

I think you'd be surprised at how much support there is for my position in the technical literature. There is nothing "ludicrous" about it. Would you like me to find some links for you?

[asiandude]

External clocking improved the cheap and mid grade soundcard or converter such as Motu interface or Digidesign interface non HD and not so much or even non on the highend converter such as Aurora Lynx or Mytek to my ears.

[Ben B]

I'm not speaking of subjective listening experiences. I'm referring to the measurable noise, distortion, and other phenomena related to clock stability/instability. There are any number of reasons why someone may prefer the sound of a converter when externally clocked (placebo effect included), however, almost invariably, the measurable performance is degraded compared to being internally clocked.

[nightscope]

Originally Posted by asiandude

....to my ears.

Your ears are irrelevant.

Here's a quote from Michal@Mytek.

"Right on. External clock is in most cases just a distortion inducing device and many people seem to like this coloration and call it improvement.

All evidence (in this case FFT distortion plots) has always proved only that.

External jitter induced by external clock typically emphasizes midrange what is then mistaken for "warmth" or "forward" or "focus", while at the same time bass and highs suffer loss of resolution.

Money would be better spent on a nice tube EQ instead.

External clock can make sense when used to synchronize complex digital systems but it "improving" sound is the biggest audio myth ever.

Michal, Mytek New York"

And another from our very own Jim Williams.

"This is true. Michal is very good at designing low jitter clocks. We have had many discussions about these issues. He is able to produce an internal clock with less than 10 ps of jitter. However, run that down 3~4 inches of PCB trace and it goes up to 100 ps. Run that down an external cable and all hell breaks loose.

This is why the clock signal is regenerated internally even if using a so called "clean" external clock. Your digital gear will never get those low jitter specs of your master external clock due to these issues.

Or, just listen to Dan Lavry."

ns

[Duardo]

I think you'd be surprised at how much support there is for my position in the technical literature. There is nothing "ludicrous" about it. Would you like me to find some links for you?

Have you ever heard Antelope's Atomic Clock (or, rather, converters clocked to the Atomic Clock)?

I am, of course, speaking of subjective listening experience.

[Ben B]

No offense, but I'm not interested in that type of discussion.

[psycho_monkey]

Originally Posted by GaryWeinrib

people who support your position have never used an external clock or don't profit from them

Did you read nightscope's post above?!

[Nick Morris]

I have used an external clock, a big Ben from apogee. I used it to sync quite a few pieces in my old system. I did notice that it had a sound to it, and it was not an improvement, but rather simply a difference. I actually preferred the sound of my converters not using the big ben. In my experience, use your WORST converters clock to sync from. The better clocks of mine seem to be able to handle it better and sound alright. The lesser converter clocks didn't fare as well. But I can't explain the whys and how comes, I just know what my gear did.

[Andrew Kinsey]

The quality of your AD & DA converters will have a greater impact in terms of improving sound quality in comparison to clocking lesser converters with a high end clock.

High end converters will also generally have a better designed clocks anyway compared to most of the mid level interfaces they are being used with.

In my current setup i am running a Lavry Gold AD as master to a Lynx AES16, and it does make a nice subtle improvement over running the Lynx clock internally and thats just on playback.

I have also tried the Antelope Trinity in my setup without the 10M, and again Trinity did make a nice subtle improvement over the Lynx. Between the Trinity and Lavry it was really difficult to decide which sounded better, infact i felt that i could go eitherway depending on the music, Lavry seemed a bit smoother but the Trinity had nice things going on in the low end. These difference are subtle, but deffinately noticeable.

Very recently i did a demo of the 10M for a customer who had already purchased the Trinity unit a while back. After repeated A/B'ing of Trinity crystal clock vs 10M input you deffinately noticed the 10M further cleared up the low end, kick drums sounding a bit less muffled, and more open.

In mastering applications the use of such clocks is becoming more common with some very reputable mastering studios installing Atomic clocks, however these guys are already using very high end converters to begin with before even considering such options.

The more passes go in and out of your system the more the effect of the converters, and clock will accumulate. So if you can hear a difference on playback alone then the difference at the end of going AD>DA>AD>DA will be even more noticeable.

[Ben B]

Originally Posted by GaryWeinrib

people who support your position have never used an external clock or don't profit from them

Only half true.

[psycho_monkey]

Originally Posted by GaryWeinrib

I read it but I don't get my information on message boards. I have an external clock and it works for me. That's all I can say. But the fact of the matter is, Dan Lavry and the other guys (who I have never heard of) are far from the authority on clocking or digital for that matter. Anyone can build an A/D converter. Just ask behringer or creative labs. however, if clocking was such an easy science, all the converters like behringer and creative labs would be good and they are not. Lastly if clocking didn't, then why are the Sony phillips digital interfaces on gigabyte and asus mother boards basically unusable for low latency low jitter connectivity? I'm not sure, that is a question for whoever ca answer. I feel it is the clock though.

Also Clocking via TDIF, AES/EBU vs lightlink vs sony Philips? word clock... no difference?

I don't necessarily disagree with your position - but if you think the guys behind mytek and lavry aren't authorities on clocking, what the f does that make the rest of us?! I'd wager they know a hell of a lot more about the technicalities than either of us...and they don't get their info online either!

Of course making a good converter isn't easy. Cheap onboard sound cards are made to a budget, hence have crap internal clocks. No-one is saying clocking doesn't make a difference! The point is, even if you could slave a creative labs card to an external clock, it wouldn't make much if any improvement - it'd still be a crap converter.

The rest of your post I'm not sure of the relevance of - sounds like an argument to something not suggested.

Bottom line - I wouldn't disrespect some of the best converter designers without having facts and proof of your own!

[psycho_monkey]

Originally Posted by GaryWeinrib

I just don't think because some someone makes or sells a product necessarily mean they are the authority on it. Burger King is not the authority on burgers and kia is not the authority on cars.

I have owned lavry products and I like them, However for all I know he could just buy ADCs & DACs from TI or AD and use their example circuits from the spec sheet. I'm no way implying he does this, but many converter mfgs do this type of thing and just jack up the price and 90% of the buyers do not know the difference.

Burger king aren't high end burgers are they though? Lavry gold is arguably top of the line AD - you'd have thought the designer has a fair understanding of clocking.

Dan lavry writes white papers on this stuff - far more than a salesman.

[Bassmankr]

First of all many get "Timing Acuracy" of what the converter recieves as clock signal confused with what sounds best to their ears. What's so hard to understand that you can only move a clock signal down a few inches of PCB board trace before interferance changes it's acuracy? Test equipment has proven this point. In fact if the PCB layout / components location are not right you won't even get that. So in order to get the most acurate clocking to your most important converter (the A to D converter) you need a decently designed circuit with the clock within a few inches of that converter (internally clocked A/D). If the A/D circuit layout isn't the greatest, if the A/D internal clock isn't the greatest, or if you use an exterior clock you will have LESS ACURATE clocking. In fact with using exterior clocking besides the clocking acuracy being messed up from the distance it travels, the recieving device doesn't use it as is, it instead regenerates it's own clock signal from it causing even further non-acuracy of clock timing. There is really nothing above to argue over as others have already pointed out. If you want more specifics and the science explained dig up the old threads on it here.

Now if you prefer this less acurately clocked sound that's a different argument and a subjective opinion. Notice how no one has said that your particular converter with exterior clocking doesn't SOUND best to your ears. They have just said the practice of exterior clocking is less ACURATE which is true. Hence BLIND TEST and use your ears. Without blind testing due to the high cost of exterior clocks, expectation bias and placebo effects creep in fast ("it costs so much it has to make things better" or "the marketing says it's the most acurate" like marketing is so truthful). So now you can see why consensus here is that without you doing your own blind testing the rule of thumb is to use your best/main A/D converter internally clocked as your master. By the way, my person experience with blind testing the few different converters around me was I always picked the internally clocked A/D converter as sounding the best. Go by the rule of thumb or get your hands dirty with a BLIND test.

Additionally from a "quality for a given amount of money" standpoint, most would be better off with a better A/D converter internally clocked as master than a less expensive A/D converter as slave with a separate exterior clock as master.

[Ward Pike]

Some threads surely make you shake your head, around here.

The single biggest leap in a DAW's sound quality I have ever heard is using a QUALITY external clock such as a Digi/Avid Sync or a Big Ben.

[Nick Morris]

So your subjective preference was for the less accurate clocking, you found the distortion to be to your liking. Fair enough.

[Bassmankr]

Well maybe not, Ward didn't state which particular A/D converter he was using with the external clocking (just the external clocks he tried). There was a fairly famous popular brand that was used in lots of studios that had terrible internal clock jitter and performed better with an external clock that it's PLL circuit regenerated to a more acurate clock signal to use. Most of the newer A/D converters have better converter chips AND a better internal clock.

Here is a basic article from 2010 to help grasp CURRENT digital clocking understanding along with test data from external clocks: Does Your Studio Need A Digital Master Clock?

Here is an article from the same publication from 2003 on digital clocking, notice how some concepts were not as understood / refined 9 years ago: Digital Clocking Explained

What the above article states correctly is how important the A/D conversion timing is especially with stereo signals for better imaging. The other important concept to grasp is once you have made that inital conversion you are stuck with it's results.

[Ward Pike]

Originally Posted by Nick Morris

So your subjective preference was for the less accurate clocking, you found the distortion to be to your liking. Fair enough.

Well that comes across as a rather arrogant bucket of "Because you don't agree with my brilliance you must be an idiot". Fair enough.

I use a Digi/Avid Sync. I used to lock together several 192s and a 96, now I use it to lock together to Avid HD 16x16 i/o units. And everything works and sounds a heck of a lot better with the sync as master clock than just using one of the internals. Other engineers I know have reported (without exception) the same thing.

There is not necessarily any added distortion.

[Bassmankr]

Ward, some question the clocking abilities of those converters or there wouldn't be people making money off their upgrades ie: Black Lion Audio | Avid HD Modification

I'd take you on face value what your ears tell you. I'm assuming you did blind testing with the HD 16x16's internal clock as master when you got it.

[Nick Morris]

Originally Posted by Ward Pike

Well that comes across as a rather arrogant bucket of "Because you don't agree with my brilliance you must be an idiot". Fair enough.

I use a Digi/Avid Sync. I used to lock together several 192s and a 96, now I use it to lock together to Avid HD 16x16 i/o units. And everything works and sounds a heck of a lot better with the sync as master clock than just using one of the internals. Other engineers I know have reported (without exception) the same thing.

There is not necessarily any added distortion.

Whoa, guess that came across wrong. Just saying it sounds like you preferred the change external clocking caused.

An external clock will add distortion. Some may find it pleasing.

In some cases an external clock may be the best route to reach the least amount of distortion. Usually this is when many digital devices are being used. This sounds like your case with the Avid units.

[AB3]

When I hook up my Antelope OCX to my Lynx Aurora and turn off the synchrolok on the Lynx, this external clocking SOUNDS like less distortion. Is it more distortion or not - technically? - I do not know - but the ears are indicating less distortion and I have other witnesses.
For instance, with a pair of DPA 4011s on grand piano bass notes - the notes are clear and sound less distorted with the external clock.
Now having said this - was this thread really necessary? Did the notes sound bad before? Not really. But they sounded tighter and better to ears and those of others. Hasn't this been covered over and over again on this board with all these various positions represented?

[psycho_monkey]

Originally Posted by Bassmankr

Ward, some question the clocking abilities of those converters or there wouldn't be people making money off their upgrades ie: Black Lion Audio | Avid HD Modification

I'd take you on face value what your ears tell you. I'm assuming you did blind testing with the HD 16x16's internal clock as master when you got it.

Fwiw the BLA comments on the avid Hd io runs contrary to just about very other opinion I've seen on them. Not saying they're not right in their technical breakdown, but they're definitely not right if they think it sounds inferior to the 192.

[Bassmankr]

Guys here are the real problems as I see them when it comes to figuring out converters / multiple digital devices / clocking.

You have to start with a decent room, at least good moniters that have decent imaging, and proper setup of those moniters for correct imaging and frequency response as a good baseline of what you are really hearing. Unfortunately we have quite a number of members here as evidenced by the setup pics they post that plop a pair of nearfields two feet apart on a desk pushed against a wall. That in itself will twist "what sounds best" of posters here.

Once you have a good baseline listening soundstage the next mistake many make is not listening to STEREO sources while testing. Because of clock signal ariving at the converter slightly ahead or behind (jitter at the A/D converter), it manifests itself with 3D info of a stereo source converted having incorect timing. It's those timing cues that our ears use to place a sound's location in the world / sphere around our bodies. The effect of incorrect 3D timing source data is that our ears now determine that source as very upfront center (a right in your face sound and placement). Now some people prefer a very upfront center sound, they may even equate that sound to punch or try to achieve it via compressors in a mix. This I think is why some find a high jitter setup sounding better as they prefer or are used to that very upfront centered sound. The problem is however when you have that very upfront centered sound without the ADDITIONAL 3D SOUND FIELD you now have the typical flat 2D digital sound that many of us can't stand to listen to for more than a few minutes at a time. So bottom line when testing use stereo sources and listen specifically for 3D.

The next big problem I see is that some converters are specifically made to be colored instead of transparent and just convert acurately. There are threads specifically about this issue so I'm not going to reopen that debate. I fall into the camp of transparent. An A/D then D/A conversion that sounds closest to the original source is the "Best" in my opinion. When testing clocking options how many compare a live source to a pass through the converters?

The last big problem I see is blind testing. Though we have been talking about doing a slutz get together for converters it has not happened yet and if it ever happens it will be a massive undertaking to do it right. The best we can do in the mean time is get some buddies and try all the options available to you. The key is still to make it blind as expectation bias and placebo effects are very real.

So all in all the current rule of thumb is a good one based on preserving the most source 3D info. There are exceptions and listener's preferences for other setups. Get your hands dirty by listening to your available options blindly (stereo sources concentrating on 3D). Remember "clock acuracy at the A/D converter" and "what sounds best" are two different things. Lets just keep all the above in mind and not slag others here if they choose a setup you may not agree with.

[psycho_monkey]

Originally Posted by Bassmankr

Guys here are the real problems as I see them when it comes to figuring out converters / multiple digital devices / clocking.

You have to start with a decent room, at least good moniters that have decent imaging, and proper setup of those moniters for correct imaging and frequency response as a good baseline of what you are really hearing. Unfortunately we have quite a number of members here as evidenced by the setup pics they post that plop a pair of nearfields two feet apart on a desk pushed against a wall. That in itself will twist "what sounds best" of posters here.

Once you have a good baseline listening soundstage the next mistake many make is not listening to STEREO sources while testing. Because of clock signal ariving at the converter slightly ahead or behind (jitter at the A/D converter), it manifests itself with 3D info of a stereo source converted having incorect timing. It's those timing cues that our ears use to place a sound's location in the world / sphere around our bodies. The effect of incorrect 3D timing source data is that our ears now determine that source as very upfront center (a right in your face sound and placement). Now some people prefer a very upfront center sound, they may even equate that sound to punch or try to achieve it via compressors in a mix. This I think is why some find a high jitter setup sounding better as they prefer or are used to that very upfront centered sound. The problem is however when you have that very upfront centered sound without the ADDITIONAL 3D SOUND FIELD you now have the typical flat 2D digital sound that many of us can't stand to listen to for more than a few minutes at a time. So bottom line when testing use stereo sources and listen specifically for 3D.

The next big problem I see is that some converters are specifically made to be colored instead of transparent and just convert acurately. There are threads specifically about this issue so I'm not going to reopen that debate. I fall into the camp of transparent. An A/D then D/A conversion that sounds closest to the original source is the "Best" in my opinion. When testing clocking options how many compare a live source to a pass through the converters?

The last big problem I see is blind testing. Though we have been talking about doing a slutz get together for converters it has not happened yet and if it ever happens it will be a massive undertaking to do it right. The best we can do in the mean time is get some buddies and try all the options available to you. The key is still to make it blind as expectation bias and placebo effects are very real.

So all in all the current rule of thumb is a good one based on preserving the most source 3D info. There are exceptions and listener's preferences for other setups. Get your hands dirty by listening to your available options blindly (stereo sources concentrating on 3D). Remember "clock acuracy at the A/D converter" and "what sounds best" are two different things. Lets just keep all the above in mind and not slag others here if they choose a setup you may not agree with.

It's basically f'ing difficult to judge....

[Tui]

Originally Posted by Bassmankr

Additionally from a "quality for a given amount of money" standpoint, most would be better off with a better A/D converter internally clocked as master than a less expensive A/D converter as slave with a separate exterior clock as master.

Correct. However, gear manufacturers are only too happy to sell you yet another box you don't need.

[mdwhitaker]

Gentlemen, thanks for all the feedback.

I didn't intend to start a big general clocking debate, as i know there are already way too many of those on GS.

For the record, I myself am with the "trust your ears" group. And im sure that there have been cases where a cheaper lock gave someone the results they preferred. I have no idea about the clocks in the lynx vs apollo but after an A/B the apollo won for my ears.

Ive got a friend who is bringing over his burl b2 for a clock shoot out next week. Im expecting the burl to shine bright, but we'll see. Or hear

[Doc Mixwell]

Originally Posted by mdwhitaker

but we'll see. Or hear

Yes, hear, then see!