# What's the word on clocks?



## Fitz (Feb 12, 2019)

In my studio, I run everything off Apollo 8 Quads. I've been seeing in a lot of studios they have an external clock like a an antelope isochrone, or something similar.

When does this become necessary in a studio? Will it sound better than what's coming out of my Apollo? Trying to upgrade the gear to get the best possible sound before I start on another project.


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## Scoremixer (Feb 12, 2019)

Totally unnecessary if you're all in one rig with modern convertors. In fact, clocking externally normally increases jitter vs doing it internally. The only reason you need external clocking is for accuracy across multiple systems, in a digital environment or if external video hardware is involved.


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## chillbot (Feb 12, 2019)

Fitz said:


> When does this become necessary in a studio?


If all you have is Apollo 8 Quads, then no. What else is connected to them? It becomes important (not exactly necessary) when you have a whole bunch of digital gear all over the place, in a nutshell.


Fitz said:


> Will it sound better than what's coming out of my Apollo?


Some people say solid clock improves the audio. Some people also say they can hear the difference between 44.1k and 48k. I dunno.

Interesting article, especially about half-way down the part about "interface-induced jitter":

https://www.soundonsound.com/techniques/does-your-studio-need-digital-master-clock

I use the Big Ben, personally. I have always had a ton of external gear that needs clock... a couple of digital mixers, my 2408 cards, my RME card in the slave computer, some digital outboard FX, the TC Electronics Finalizer.

I could clock everything to one source using a combination of the right SPDIF, AES, and ADAT cables. But in my experience getting sync via these cables is much less reliable than word clock. I don't notice jitter but I do notice occasional pops or clicks in the audio from devices clocked this way, especially via lightpipe, which has to be run very carefully. I recently bought a RME wordclock card for my slave computer and it has noticeably made a difference in the audio that used to sync via ADAT, regarding pops and clicks.


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## JohnG (Feb 12, 2019)

chillbot said:


> Some people say solid clock improves the audio. Some people also say they can hear the difference between 44.1k and 48k. I dunno.



lols

I do think you can hear the difference if you go from "rubbish" to "good" on the D/A converter. How much that has to do with a better clock as well, I couldn't guess. An awful lot of "testimonials" on this subject in general.


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## JohnG (Feb 12, 2019)

But to answer the OP, you don't really need a clock until, as @chillbot wrote, you have "a lot" of digital stuff (outboard FX, many computers with sound cards, maybe a hardware mixer...).

Like him I also use Word Clock for sync unless for some reason it's not on the device.


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## Nick Batzdorf (Feb 12, 2019)

This was a big controversy 20 years ago. Bob Katz, a mastering engineer, said that you need to shout at the designer of your equipment if it sounds better with an external clock. His argument was what Scoremixer says - that recovering an external clock from a PLL (phase-locked loop) is intrinsically more jittery than using an internal clock.

I did a lot of playing around with clocks at the time (because I had several digital devices). My bottom line:

- Whenever possible, use the device doing the A/D as the clock master;
- If you can run wire between two or more devices, either using word clock or just "digital black" clock, instead of using the clock embedded in the digital datastream along with the audio, it will probably sound better;
- Do not use lightpipe for clocking, because a) it's not very reliable, b) it won't sound as good. ADATs used a (was it 10-pin?) wire for syncing multiple tape machines, while using lightpipe for audio.

Today - not in the past, today - I personally wouldn't buy a clock generator. Every good audio device, whether it's an interface or processor, has a good clock, and I'd rather invest in that. If you need to clock multiple devices to word clock, a standard video distribution box (they're cheap) will work.


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## benmrx (Feb 12, 2019)

Clocks in music studios = bad
Clocks in post production studios = good

Oh wait...., you're talking about 'those' kinds of clocks...haha.


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## JohnG (Feb 12, 2019)

Nick Batzdorf said:


> - Whenever possible, use the device doing the A/D as the clock master;
> - If you can run wire between two or more devices, either using word clock or just "digital black" clock, instead of using the clock embedded in the digital datastream along with the audio, it will probably sound better;
> - Do not use lightpipe for clocking, because a) it's not very reliable, b) it won't sound as good. ADATs used a (was it 10-pin?) wire for syncing multiple tape machines, while using lightpipe for audio.



good advice


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## wst3 (Feb 12, 2019)

a couple of anecdotes about clocks...

once upon a time it was true that an external clock could help some converters, even if it was the only box in the studio, and especially if there were multiple boxes in the studio. I think today it is as much a matter of convenience as anything else, most clocks are pretty stable already.

That said, it is NOT a trivial task to build a good clock circuit. Shocking though it may seem, the reference designs are getting worse and worse, I would not bet the farm on a reference design. Yet many designers do. (the same applies to analog stages, power supplies, pretty much every building block.)

And, while I doubt I can hear it any more, there are differences between even well respected devices. Not always a good vs bad thing, but differences do exist.

Many years ago a friend and I set out to build a personal mixer system that used a novel (at the time) new network audio protocol - AVB. We learned a few things along the way. It was my first foray into switching power supplies, I still don't like them, but you can design a good, clean power supply with a switcher. And it will be oodles (that's a tech term) more efficient than the equivalent linear power supply.

And clocks? WHOLY CARP, clocks are difficult. There are so many choices to make, multiple clocks running asynchonously vs multiple clocks locked together vs a single divided and distributed clock vs heaven knows what. Trade-offs galore!

What I really learned is that it makes sense to pay attention to the details, but ultimately Mr. Katz was right.


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## dgburns (Feb 12, 2019)

In my travels, my Big Ben does indeed change the sound. I think it works well while recording. I like the sound of my SSL madixtreme pcie card as master better when I’m working in the box. 

I want to try that Antelope OCX

edit

If you have just one interface, no need for external clock. You’d be way better off getting something like Sonarworks Reference 4 to calibrate your monitors (and perfectly internally clocked interface)


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## Nick Batzdorf (Feb 12, 2019)

Nick Batzdorf said:


> If you need to clock multiple devices to word clock, a standard video distribution box (they're cheap) will work.



Actually, I bet it would work for S/PDIF too. But it's been a long time since I've had to deal with digital clock. Vienna Ensemble Pro takes care of all that by itself.


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## Gerhard Westphalen (Feb 12, 2019)

wst3 said:


> I think today it is as much a matter of convenience as anything else, most clocks are pretty stable already.


Which is exactly why I'm against Antelope gear. The fact that their Atomic clock (which is already a flawed concept and not the best clock around) makes a large improvement on their interfaces means that they're putting in compromised clocks just to make it so that you want to get the Atomic. If they put their best foot forward designing the clocks in their gear then their 10MX wouldn't make a large difference.


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## Gerhard Westphalen (Feb 12, 2019)

For anyone that wants the end-all info on clocking there's an article called - 

Pink Paper #002 – The Future of Clocks: Clarifications in the Audio Clocking Paradigm

Their website seems to not be working right now so if anyone finds a PDF, please let me know.


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## Fredeke (Feb 12, 2019)

I'm sorry I can't find the article anymore, but I read one in which an engineer made measurements on a series of modern pro-grade converters, and found out this : most converters distort more when slaved to an external clock, no matter how good that clock is, because it is somehow harder for them to be a good slave than a good master.

(Does anyone know what article I'm talking about, and where to find it ?)

So my take regarding master clocks is this :
1. I don't need one if I just have one converter device, and I still don't need one as long as all converters can synchronize to each other through either the digital signal or, possibly better, their dedicated clock BNCs. Which covers 99% of all possible setups.
2. Since I have several converters, I set the best (aka more expensive, hopefully) of them as master, so that it sounds as good as it can, and accept to compromise on the sound of the lesser ones by slaving them. (You can't avoid having slaves anyway, as soon as you've got more than one.)

These effects are of course very subtle. And because they are measured doesn't necessarily mean they will be heard.
But I see no point in investing in a master clock just for the sake of it, if improvement isn't guaranteed, and there's even a risk of making things worse - albeit very slightly.


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## Nick Batzdorf (Feb 13, 2019)

Fredeke, it sounds like the article you're talking about says what I wrote above, and yes, I agree that you don't need a dedicated clock.

As to your #1, it doesn't matter whether you're using word clock (what you call BNCs) or just digital black (a regular S/PDIF or AES cable used for sending clock only).

Your #2: please re-read what I wrote above. I don't claim to be a god, just a demi-god, but I have done a lot of experimentation with and reading about clocking setups.

Re: the effects being subtle - yes, and also remember that in the big picture, jitter is only likely to affect the actual audio file while you're recording through A/Ds (which is why it makes sense to use the device doing the A/D as the clock master). File transfers between devices either succeed or fail, leaving aside error correction and other subtle issues that are different subject.

In other words, the reason dedicated clock generators were originally made was "house sync" - keeping devices locked in commercial facilities so they didn't get clicks and pops. Tweaky audio considerations came later.


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## sleepy hollow (Feb 13, 2019)

Nick Batzdorf said:


> ADATs used a (was it 10-pin?) wire for syncing


9-pin D-SUB cables/connectors were used to sync multiple machines. 'Sync Out' of machine #1 was connected to 'Sync In' of machine #2. From there the sync signal was passed on to machine #3, the unit that ate your tape. Great fun!


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## Fredeke (Feb 13, 2019)

Nick Batzdorf said:


> Your #2: please re-read what I wrote above. I don't claim to be a god, just a demi-god, but I have done a lot of experimentation with and reading about clocking setups.


Do you mean to say that I should have said "use your best A/D converter as a master" ?
If so, I stand corrected.



Nick Batzdorf said:


> In other words, the reason dedicated clock generators were originally made was "house sync" - keeping devices locked in commercial facilities so they didn't get clicks and pops. Tweaky audio considerations came later.


Yes, I agree a clock should be seen more as a utility device than as a sound peripheral.

Anyway, you do have more experience than me. I was talking from a purely theoretical point of view. I'm glad we agree, it means I'm not completely off the mark


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## Nick Batzdorf (Feb 13, 2019)

Fredeke said:


> Do you mean to say that I should have said "use your best A/D converter as a master" ?



If you have more than one A/D converter.

The only time jitter - that is, subtle clock speed variations heard as distortion - affects the audio permanently is when it's being recorded along with the audio. Jitter in, say, your D/A converters doesn't affect the audio file itself, it just sounds bad while you're playing it back.

So if you believe (as I do) that digital things are happiest running off their own internal crystals, you slave all the other stuff to your A/D converter.

Sorry for being a niedermeyer, but it's very important to the world that this be clear.


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## Fredeke (Feb 13, 2019)

Nick Batzdorf said:


> The only time jitter - that is, subtle clock speed variations heard as distortion - affects the audio permanently is when it's being recorded along with the audio. Jitter in, say, your D/A converters doesn't affect the audio file itself, it just sounds bad while you're playing it back.
> 
> So if you believe (as I do) that digital things are happiest running off their own internal crystals, you slave all the other stuff to your A/D converter.
> 
> Sorry for being a niedermeyer, but it's very important to the world that this be clear.



Well it makes perfect sense and my hairs are never too split


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## dgburns (Feb 13, 2019)

Not disputing the science, external wordclocks do not improve the internal clocks.

But I wish people would just try the external wordclocks and hear for themselves. I do believe the external clocks will change the way interfaces sound, and this is evident in the recordings I’ve made.


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## Nick Batzdorf (Feb 13, 2019)

dgburns said:


> Not disputing the science, external wordclocks do not improve the internal clocks.
> 
> But I wish people would just try the external wordclocks and hear for themselves. I do believe the external clocks will change the way interfaces sound, and this is evident in the recordings I’ve made.



The argument is that if the external clock improves the sound, there's something wrong with the equipment's design - not that it doesn't improve it!

I've heard at least two people, one a professional engineer whose opinion I take seriously, say the Big Ben improved their MOTU 896s, for example.


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## synthetic (Feb 13, 2019)

I use one. I have a few thoughts. First of all it only makes sense if you have great quality gear to begin with. You're talking about what kind of icing to put on the wedding cake, really subtle stuff. Second of all I've stopped reading articles about the technical reasons why something sounds good or not. Hell, I've written some of them in one marketing gig or another. Listen for yourself, and if you don't hear an improvement, stick to the simpler system. Also, I have a complex system with three computers, two ADDAs, MADI, and all kinds of stupidity that's way too complex. So I figure a master clock might keep everything in line. 

I tried one out (TASCAM CG-1000 on my SSL converter) and I immediately thought it was different, but I wasn't sure if it was better. I had to live with it for a while. I've noticed that with subtle audio changes like high-res audio. Listen to nothing but hi-res (96k/24 or better) for a week, then switch back to iTunes or CDs and you'll hear it. The clocking thing was similar, it was a different sound but eventually I learned what to listen for and liked it better. 

Last thought is that a lot of this mystic audio stuff might make things 1% better. Cables, acoustics, preamps, etc. etc. But the 1%'s compound to the point that it starts to improve. You might not notice the difference changing one cable in your setup, but change all of them and you might be surprised. 

For most people, I'd suggest saving for a better converter than a master clock. Like maybe going from the UA to an Apogee Symphony or something might be a better investment than putting a master clock on your UA. (Though I haven't used many UA converters so I don't really know.) 

OK, one last thing, the Big Ben is like 20 years old. Look at the PPM drift of the clock as part of your shopping (the TASCAM is actually more precise than most Antelopes.) Though some people think the Big Ben sounds better even though it's not as precise. Pro audio be like that sometimes.


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## Fredeke (Feb 13, 2019)

dgburns said:


> But I wish people would just try the external wordclocks and hear for themselves. I do believe the external clocks will change the way interfaces sound, and this is evident in the recordings I’ve made.


Sure it may sound different, but that doesn't mean better. Of course appreciation is subjective, and one can like a more distorted signal better. But there are less expensive ways of adding distortion 

Ok, more seriously...

Some converters may actually be improved by an external clock, but as Nick said, that only says long about the converter's poor quality to begin with. And as Synthetic suggests, why not invest in a better converter/interface instead of a clock ? The improvement will certainly be greater !

I haven't got much experience with clocks, but I've tried the Mutec MC3 once, just to test the saying that clocks make everything sound better. In truth, I couldn't hear any difference. On the other hand, I've tested several different converters (running off their internal clock) before settling for my current ones, and the differences from one to another were (dare I say) obvious.

In short: in the same price-per-channel range, which converter sounds better is a matter of personal taste, while more expensive ones consistently sound more transparent and better defined. Which are qualities I've often heard attributed to the use of a master clock, but that I would more readily attribute to the quality of the converter itself.

(Still have the Mutec btw. Is for sale. Just saying.)


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## dgburns (Feb 14, 2019)

Nick Batzdorf said:


> The argument is that if the external clock improves the sound, there's something wrong with the equipment's design - not that it doesn't improve it!
> 
> I've heard at least two people, one a professional engineer whose opinion I take seriously, say the Big Ben improved their MOTU 896s, for example.



Ha ha, my SSL madixtreme outputs 47.96k, not 48k. No idea why. But that has to be a red flag. I know this because I tried to use it as the house sync master, and when I fed it to the Big Ben, that is what the Big Ben readout said.


Fredeke said:


> Sure it may sound different, but that doesn't mean better. Of course appreciation is subjective, and one can like a more distorted signal better. But there are less expensive ways of adding distortion



Yeah, I totally agree with everything you're saying, once again. But I have yet to find any plugin that replicates the effect of the Big Ben on my sound. I don't like it on everything, but I do like it on certain styles of music.


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## Nick Batzdorf (Feb 14, 2019)

Fredeke said:


> as Nick said, that only says long about the converter's poor quality to begin with



Well, I should backpedal half a rotation.

I've played with different devices being the master, and at the time I had several good units (including a Waves L2 hardware limiter, multiple decent audio interfaces, a Panasonic digital mixer...), but I've never had a dedicated clock unit to play with. My conclusions are what I wrote above.

Yes I believe that Bob Katz knows what he's talking about, and at one point I even understood his reasoning, but that's theoretical. And no way do I claim to know anything about actually designing digital audio equipment!


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## Fredeke (Feb 15, 2019)

dgburns said:


> Yeah, I totally agree with everything you're saying, once again. But I have yet to find any plugin that replicates the effect of the Big Ben on my sound. I don't like it on everything, but I do like it on certain styles of music.


Nothing to say against that. Respect to your tastes, sir. I wish I could stand next to you and listen to what you're hearing 'cause you got me curious. (With a little lack of luck, maybe I'm not even able to hear the subtleties we're talking about)


Nick Batzdorf said:


> Yes I believe that Bob Katz knows what he's talking about, and at one point I even understood his reasoning, but that's theoretical. And no way do I claim to know anything about actually designing digital audio equipment!


Duely noted. Same here.


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## synthetic (Feb 15, 2019)

Perhaps Bob Katz is using a better DA converter than you are. (And monitors, amps, tailor...)

Lot of people who don't own or use master clocks in this thread. Your typical internet experts.


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## Nick Batzdorf (Feb 15, 2019)

synthetic said:


> Perhaps Bob Katz is using a better DA converter than you are. (And monitors, amps, tailor...)



Well, that would just make it easier to hear the effect.

He was adamant about it and put it in absolute terms: recovering the clock from a PLL is inherently more jittery than using an internal crystal.



> Lot of people who don't own or use master clocks in this thread. Your typical internet experts.



Says the purveyor of clock devices to Her Majesty The Queen...


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## tmhuud (Feb 15, 2019)

Big Ben.


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## dgburns (Feb 16, 2019)

I was hesitant to continue contributing to this thread, but there’s a few thoughts I’d like to share about my real world travels with this topic.

I’ve used mostly Avid 192 interfaces with Protools during the last twenty years or so. I used the older 888 interfaces before that, and to be honest, I don’t remember the sound, only that when the 192 came out, it was a clear improvement. In my home setup, I’ve used a bunch of lesser type interfaces. The one distinction between higher end interfaces and lower grade ones, for me, is divided into three things.

- Analog section
- Converter quality
- Clock and it’s ability to resolve to external sources.

Firstly, I found the lower grade converters always had cheaper analog sections, and this area really affects the end result, maybe the most actually, imho. The different analog circuitry, and also any filtering can really change the sound of your recordings. As an example, for a time, I was using an Aurora Lynx 16 with the Aes pcie card. Boy, that setup was very uncoloured. So much so that I had a hell of a time working with it. I never realized, by comparison, how coloured the Avid 192 analog section really was. The Avid also seemed to compress transients way more then the Aurora did. As a reault, I found myself limiting and clipping and saturating audio in the DAW way more with the Aurora. And I also found myself discovering that stuff didn’t translate as well when it was played back in the mix. The mixers were using all Avid interfaces. I decided it might be a good idea to hear things the way it would be in the final mix session, so back to the Avid interface.
Also, it was at the time I was using the Aurora that I tried out the Big Ben. Mostly in a bid to find a way to get the Aurora to work for me. I discovered that the Big Ben added alot of low end and softened the high end. It made it easier to work with the Aurora, for me. Ultimately, I went back to the Avid and discovered the Big Ben made them sound a bit bigger, for lack of a better word. I could tell it was less accurate, but at the time I needed a good sync source for many devices, so the Big Ben stayed. I also discovered that to capture the effect of the sound I was hearing, I needed to round trip out the converters to print the sound and make it translate to the outside world.
I like the Big Ben, I know it’s not more precise, but it seems to help me write and it imparts a sound quality on my recordings that sounds vaguely similar to the way tape does. It gets me closer to the finished sound faster. So again, imho, it is helpfull.
Once in a while, I turn it off, and find the sound duller and less wide. I don’t dig the bump in the extreme low end all the time, and find myself trying to carve it out. I also don’t like the way it makes some instruments harsher in the high end, especially violins. As a result, I’d like to try the Antelope OCX, which seems to not have these issues.
After calibratng my room with the Sonarworks Reference 4, I find the room is closer to flat then it’s ever been, external clock or no.

So does any of this help write better music? No not really, but I tend to really get inspired when the sound itself gives me something back. The Big Ben does is fact do this for me. 

sorry for the book

David


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## Nick Batzdorf (Feb 16, 2019)

dgburns said:


> The one distinction between higher end interfaces and lower grade ones, for me, is divided into three things.
> 
> - Analog section
> - Converter quality
> - Clock and it’s ability to resolve to external sources.



I also wonder how much effect the DAWs themselves have on the quality, especially some of the plug-ins.

What I heard when comparing several interfaces over a few weeks was that they sound less brittle as you go up in price. That was over ten years ago, though, and - again - we're now in the golden age of digital audio.

Still, well before that, I never thought the 888 and 888/24 were as horrible as people said - they sounded like what you recorded. People didn't make the same comments about ADATs or DA-88s, and they didn't have exotic converters on them. I think a lot of people just had fun complaining about Goliath.


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## Nick Batzdorf (Feb 16, 2019)

Also, what Jeff says about details being cumulative is definitely true. Cables really can be audible, for example.

But you know what makes a much bigger improvement to the sound than the converters? Mic preamps.


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## danbo (Mar 18, 2019)

In my estimation these days good _clock distribution_ is more important than finding a better clock. Clock degradation would probably be the more common problem (note my day job is in converters at RF frequency for military, NIST, etc). Yes even at audio freqs this stuff is important, but get the low hanging fruit first.

In my studio I have two outboard DACS, one 8 channel DAC, and two audio interfaces, one with a lot of DANTE I/O, so I have clocks being distributed all over the building! Having good clock recovery is important too.

The master clock is studio A RED4PRE, with word clock to a *Drawmer DMS-4* clock distribution. Cabling with proper termination is important, you need to have a star configuration! The DMS-4 buffers the clock out to the DACS and a second audio interface. The RED4PRE is also the Dante clock master for the converters/interfaces in the other studios.

On network clock the switching is important. I have three Cisco business managed switches as recommended for Dante, with traffic shaping for the clock distribution. This is better in my estimation than a simple dedicated network, as hosts still push packets over the network - you need traffic shaping. 

Even USB interfaces have clock recovery issues. I did an experiment with a ultra resolving pair of Stax 009's on a R2R DAC on USB - yes using insanely good cables with a good clock recovery box did make a difference, albeit somewhat subtle. 

If you have anything more than a single interface I'd suggest first getting a clock distributor, with really good, short cabling if possible. That will easily handle all the terminations and such for you.


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