more word clock confusion

wes480

wes480

New member
I almost put this in the computer soundcard forum but it made more sense to me here since it deals somewhat with external clock questions.

Basically I understand that word clock is for syncing digital devices more or less? Though I certainly do not understand this fully...but that's ok, I don't really do digital sources/transfers.

In the past I used an Aardvark Q10 and was always told that the nice Aark clock it had - was making my signal sound better? (even when just running into the pres and recording my mics etc, not using the digital ins/outs).

Now I have a Presonus Firepod and it has an external clock hookup, as well as a sync light on the front to tell you if there is digital sync.

In the manual it mentions that if you have no external word clock, it will sync with the PC. So is that by means of an internal word clock - that controls the digital information back and forth to the PC (or Mac)?

My question is...given someone in my situation - only using mics as sources, not concerned with spdif i/o, connecting right to a computer etc...

Is there going to be any advantage to buying an external word clock instead of using the internal clock of the firepod?
 
Only if the external clock is of sufficient better quality than that in your Firepod.

tom
 
Great subject since I'm looking into the same sort of questions. One difference in my setup though - I've got an external sound module that can output SPDIF, and I've also got a separate Giga computer running sound libraries.

The fundamental improvement you get from an external word clock (as I understand it) is the stability it lends to the A/D and D/A conversion process. A lesser clock generator can have significant jitter which manifests itself as a blurring of the stereo field and less clarity in each instrument; I think this can be more pronounced at either the high or low end of the spectrum, I forget which.

I don't know what brand word clock you'd need in order to get a better sounding system, but names lilke Apogee, Lucid, and Lynx come to mind.

I'm hoping that an external generator will also improve the quality of the sound I get from SPDIF sources module and Giga computer.

BTW WES480 - I bought my Aardvark Q10 years ago after PMing you to ask for an opinion. Good to see you're still around.
 
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Hey Phyl good to see you. I haven't been on the boards in a while - actually I sold my Q10 about a year ago because I was moving, didn't have time for it...etc.

But I got the itch again and did the Firepod thing - no real experience with it yet though. Shame to see that Aardvark went out of business (apparently) but what can you do? Doesn't mean their product can't still be used with good results for a long time to come.

So I am confused by the setup arrangement of things.

The best explanation I have heard of what the word clock does - is takes the audio signal, and slices it up into little pieces of digital information based on the sampling rate - so that the information can be buffered to whatever device.

If right now I am using the internal clock of my Firepod - it is working with the information and then sending that to my computer for recording? What about playback - or does the clock not really matter there - since it's just digital information being transferred to the card for playback output.

Say I bought something like a Lucid Genx6-96 clock which as far as I know is pretty high end and should be better than what is in my Presonus.

How does it hook up? Is it the kind of thing where you plug it in and it automagically makes your whole system better?

I guess I am still shy on the real benefits. Obviously though it pertains to more than simply using SPDIF?
 
There is a very long thread over on PSW where Dan Lavry conclusively argues that the best performance should be achieved by a converter using its own internal clock.
 
yah i actually found that a while ago on a google search..

it was over my head for the most part...

so he is suggesting that the entire external word clock industry is a waste of time - and that everyone should just do the best they can with their own internal clocks?
 
wes480 said:
yah i actually found that a while ago on a google search..

it was over my head for the most part...

so he is suggesting that the entire external word clock industry is a waste of time - and that everyone should just do the best they can with their own internal clocks?
Click to expand...

No it's not a waste if you have multiple digital devices.

Edit:

That is to say that if you only use a single A/D converter your money is better spent upgrade that converter, not buying an external clock.
 
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mshilarious said:
There is a very long thread over on PSW where Dan Lavry conclusively argues that the best performance should be achieved by a converter using its own internal clock.
Click to expand...

I would not say that he conclusively argues that. He puts forth a strong argument, but I would not say it is conclusive.

However, I do agree with him in that if you are syncing just two pieces of gear, in your example, a firepod and whatever the source of the digital sugnal would be, then the internal word clock of the firepod would do fine.

However, if you have more than just the two digital devices then an external word clock is indicated. In my case, I have 6 digital devices, and the word clock is a must. FWIW, I use a Lucid Genx, not being able to afford a Big Ben at this time :)
 
I clock my system with the Lucid. It connects with a 75 ohm video type cable termintaed with BNC connectors. The you set whatever you hooked it to to clock to it (an external word clock).
 
fraserhutch said:
I would not say that he conclusively argues that. He puts forth a strong argument, but I would not say it is conclusive.
Click to expand...

Yeah the problem was the boys on the other side wanted to protect their trade secret, if there is one. Suffice to say I found Lavry's approach more scientific--after all, they were arguing about a measurable statistic.
 
Just from my experience, word clock definitely makes a difference. I have a Delta 66 and an ART Di/O (which gets some great reviews by pros for it's A/D D/A converters). The Di/O can serve as the master word clock for the Delta 66 via an spdif output. The software control panel for the Delta allows you to switch between the internal clock and an external clock (the ART Di/O) on the fly, so it's easy to compare the difference.

What I've found is that when I switch to the Di/O, the stereo field opens up noticeably. It gets much clearer, and the separation between the instruments is increased. It also seems as if the low-end tightens up a lot; the bass sounds punchier and less muddy.

All in all, it's actually a fairly big difference, and I was pretty impressed with the results when I first tested it. Does it make as much of a difference as a better preamp, better mic, better monitors, or better room treatment? Nope. But for the money I paid for the Di/O, I'd say it was a worthwhile upgrade.

Good luck,
Ryan
 
I thought that Dan (and Bob Katz) argued pretty conclusively in that thread. You had them talking science on one side, and the Apogee guys talking marketing on the other. Dan & Bob didn't leave much doubt in my mind that a converter unit operating under it's own clock (assuming a great clock or even a decent one) would outperform a converter operating under an external clock.

Of course, if the converter in question can output WC, then you can distribute that to the rest of the system. An external WC is often a thing of convenience though, and makes it a lot easier to sync up multiple digital devices to the same clock. That's why I use one. I have 16 devices that I need to sync, and having the master clock does help with that.
 
How is everyone? I'm looking around the net for word clocks, but I can't find detailed info on master word clocks or distribution systems. So if anyone has any links to any sites that go in detail about these devices, I'd greatly appreciate if you can post them here.

Thank you
 
I use the Lucid clock as well, we've been impressed with it. I'm syncing up 5 devices with it and no issues, good sound.

War
 
the way i see it, the real big reason to use an external word clock is because of the crystal inside of it.
word clocks give us perfect (or more perfect than a stock A/D converter soundcard does) constant bitrate. this helps avoid data errors. In other words, it tells the computer to operate at a certain frequency and stay at the frequency. It's similar, i guess, to what a power conditioner does. A power conditioner in your studio won't give you a better sound out of your recordings, but it will help prevent dirty electricity from affecting what you're doing. Same thing with a word clock. It "cleans" the frequencies your digital data is being sent down and keeps it steady, so that no errors will occur.
 
Well, sorta. What it really does is provides a genlock - a steady pulse that frames a sample (start, stop). It *is* the clock. That way, all devices are synced as to the start and duration of a sample.
 
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