External Clock Configuration - Digital Sync

[doktor1360]

As I've still got my gear pretty much torn down as my space reconfiguration ensues, I'm still doing some integration testing of a new Cranborne R8 unit all the while in the interim. Here's where I'm at:

What I'm attempting to configure is what I think should be a relatively straight forward operation. The overview would be to utilize an external word clock source (Cranborne R8 @ 44.1kHz) as the master clock to slave my D8B and HDR. Physically, I have the Cranborne R8 set use it's default internal clock as the Master of the system, configured from my mac mini machine (via usb) per the Cranborne docs. It's then physically connect to the D8B's Apogee clock card (input) with a BNC 'T' connector, which is then connected to the HDR's clock card (input) and terminated (switch pushed 'in' on the clock card bezel)... all with quality coax cables. Understanding the D8B can be a cantankerous mf-r when it comes to this clock sync issue, I booted up the D8B 1st to completion (it was looking for a word clock - flashing '?' in fluorescent display), turned on the Cranborne R8... nope. Booted up the HDR just in the odd event it didn't like not seeing a termination point... nope again. Checked to ensure both the D8B and HDR had the external clock selected for digital syncing... and the D8B still reports back a 'lock error' regardless. Just couldn't get it to 'play nice' and syncronize regardless of any efforts so far... it's been the typical config/test/rinse-repeat cycle of triage to attempt to mitigate this...

Startup Sequence : [D8B] -> [R8] -> [HDR] or [R8] -> [D8B] -> [HDR]

Neither (or any) sequence used in attemtping to establish a start order was successful for whatever reason(s) as of yet...

I reckon the worst case scenario for the here n now, I'm pretty sure I can always just slave everything to the Apogee clock from the D8B (Master), which would be connecting the R8 into the existing configuration I've been utilizing to date - just by dropping the R8 between the D8B and HDR with the relocated BNC 'T' interface connector.

Startup Sequence : [D8B] -> [R8] -> [HDR]

Ideally, I'm looking for it to essentially be a coaxial clock system (existing), with a master clock (new R8) being utilized to slave two units (existing D8B, HDR) from the master being provided.

Any thoughts or input, or should the D8B's Apogee clock be the choice of master clocks as a default?

Thanx in advance, y'all...

[Phil.c]

I have an external master clock running both D8b and HDR with no problem, seperate cables but I've also used a T connector, before I had the master clock, I used the HDR as master, running to D8b and a Mac with Logic. Using the HDR instead of the D8b is a more stable option.

[captainamerica]

Hi Dok,,,,my D8b is the master to all my other devices and no issues. I assume your cables are all good?

[doktor1360]

I have an external master clock running both D8b and HDR with no problem, seperate cables but I've also used a T connector, before I had the master clock, I used the HDR as master, running to D8b and a Mac with Logic. Using the HDR instead of the D8b is a more stable option.

Hi Dok,,,,my D8b is the master to all my other devices and no issues. I assume your cables are all good?

Gentlemen... I very much appreciate the input and experience with this subject matter and the expedited replies - it does not go unnoticed...

captainamerica, that's how my own platform of gear has been working until I've introduced this R8 interface. The R8 provides a really stable master clock that I'd really prefer taking advantage of, along with having the other clock configuration options at hand if necessary. More below...

Phil, that's interesting. I'd like to know exactly how that external master is physically connected - especially without the use of a 'T' connector if possible. I've run a battery of tests, and I was actually able to get the syncing complete; albeit utilizing the D8B as the provider of the source master clock. Turns out I have to terminate things on the HDR using the bridged setting of the terminate switch on the rear panel - it's in the 'out' position (3.3k Ohm) and front panel clock LED is dead solid red, so it's certainly happy with the master clocking source.

As I indicated above, I ran a series of tests and this is what I noted... firstly, the cables, t-connector and hardware all check out. Connected the D8B to the HDR as per the default (no R8 in the mix), and things came back up without an issue. Oddly, even tho it was 'working' properly, the clock LED on the HDR was blinking indicating the expected external clock is not present... hrrmmm. This is what really threw me for a loop and noted the termination switch on the HDR's clock card was 'In' (75 ohm) and the synchronization was still blinking... but when I engaged the bridged mode 'out' (3.3k Ohm) it sync-d up solid... OK, never actually noticed this before... duly noted tho. I then added the R8 into the mix, connected the D8B clock out to the R8 clock in, and then connected the R8 clock out (no kidding, no 'T' connector involved) and then to the HDR clock in and keeping the switch 'out' in the bridged 3.3k Ohm termination, booted everything up in correct order (D8B, R8, HDR) and it all appears to be working... go figure. Yeah, as I indicated, no 'T' connector involved as the Cranborne docs state that the BNC clock connectors for the word clock function as follows:

[Clock In]
"Note :When slaving 500R8 from an external clock, its own internal clock syncs to the incoming timing information and recovers its own improved clock. For the best results and the highest quality conversion, we recommend using 500R8 as the clock master of your studio."

[Clock Out]
"The Word Clock Output connector sends out 500R8’s current timing information in order to slave other digital units off of 500R8’s internal clock. If 500R8 is slaving from another source, the Word Clock Output passes through the recovery clock information to sync further downstream equipment."

That fact that Phil has an external master clock providing sync to his platform - maybe that bridged termination mode is what's required with my own platform hardware mix, with the 'T' connector on the D8B and HDR last in the chain as I had done before. Difference here being that bridged mode setting maybe. Dunno, I won't until I test it all... I reckon I have a regimen of configuration testing to work out late tonite or tomorrow...

Feel free to jump in if I didn't make any sense and/or worded things in a confusing manner in the process. I think I'm close to working this out regarding providing the external master successfully, but worst case scenario the Apogee card in the D8B is (I've always found) rather stable in it's own right... it works well, seamlessly with what IS available tech-wise on the platform... essentially 'problem' solved...

Thanx in advance for contributing tho, it's been helpful...

[Y-my-R]

Per this database article, the Apogee clock card is hardwire-terminated:

http://www.sonido-7.com/d8b/wordclock.html

So, I'd think that you wouldn't need a T-connector and separate Terminator at the D8B end, no?

I'm not at the studio right now and can't look... but I don't think I have a terminator on there at the D8B end. Quite the opposite... when I used to run two D8Bs (now it's only one), I had a modded Apogee clock card on the first D8B the clock cable went to, and had the termination switched off on that one. There, it was connected with a T-Connector that allowed me to pass the clock signal on to the next D8B (it did NOT Work for me to use the second clock-out/thru connector on the Apogee Clock card for that purpose... still not sure what that's even for).

So, it kinda sounds like you might have the D8B "double-terminated"... maybe that's the issue?

I use an external clock nowadays (Lucid GENx192), and it has convenient LEDs next to the BNC connectors in the back, that tell you if the other end is terminated properly or not. And it's surprising... it's not always what you'd think. But then again, I remember that I have "something" connected that doesn't show proper termination, that syncs just fine (I really have to go to the studio to look what's what).

Also, what clock rate does the Cranborne default to? Hopefully either 44.1 or 48 kHz, since the D8B can't handle anything else?
I don't remember if I ever had trouble with the D8B with this, but I also remember that I had devices that refused to clock as slave to Digidesign's "super clock" - that clock was SO awesome, it wouldn't work with my other gear - yay, haha.
I don't know how exactly that works, but if there's any setting to turn any sort of "super-clock" nonsense off on the Cranborne (if it has something like that), I'd try without that.

Another tricky thing (that I doubt the Cranborne does), is that some low-end audio interfaces with digital inputs, "auto-sync" to incoming clock, once that's connected. I've seen such poor designs, where the only option for them is to auto-sync, but if you actually want to create a loop, where that device is master, and the clock eventually returns to it, it tries to "sync to external" and goes into an endless lock/unlock/lock/unlock loop.
Long story short... if the Cranborne has any sort of "auto-sync" setting that can be turned off, and the unit set to be Master and nothing else, that would also help.

Anyway... again, not at the studio right now, but I can take a look at how I have it all wired up tomorrow. But I'd first try without the terminator on the D8B end, and look if the Cranborne has any sort of setting that prevents it from trying to auto-sync to incoming word clock.

Sorry for the incoherent ramble... I have trouble picturing all that from memory right now.

[Phil.c]

At one time I had four units clocked from an HDR, a second HDR, two D8B's, a Moto 2408 and a Mac for Logic, difficult to remember exactly what I did now but everything worked, I remember using more than one T connector, some units were in and out I seem to remember, I later changed to a master clock as that is the way to go, just seperate send cables to each machine.

[Y-my-R]

I'm back at the studio and have a couple of notes:

So, I can confirm that I do NOT have a terminator on the D8B end (D8B running as slave to Master Clock) and the Lucid tells me that the D8B end is properly terminated.

So, this means that an unmodded D8B/Apogee clock card IS internally terminated, and you should NOT daisy-chain another device that needs clock off of it (unless you modify the card to remove termination or make it switchable).

I suspect that that's also why the HDR is acting as if termination is on, even though the switch is out. It probably sees the termination that is (improperly) present on the D8B, where you're daisy-chaining the HDR from.

I think there's a pretty simple solution, though:
R8 clock-out (Master)->
-> T-Connector on HDR clock-in (Slave - switch in OUT position)
-> Other side of T-Connector passing on to daisy-chained device (D8B)
-> D8B/Apogee clock-card in (Slave - no T-Connector on this end. Already terminated internally).

This should give you proper termination on the R8 and D8B ends, but not at the device in the middle of the daisy-chain (HDR).

Having said all of this... when I checked my own clock wiring today, I noticed that the HDR button was out, and that the LED on the back of the Lucid said that this connection is not properly terminated... and that's the correct observation. It never complained about there being an issue with word-clock, though, and I didn't hear any clicking or obvious jitter, etc.

I pushed the terminator-button on the HDR in, and the Lucid's LED for that connection turned green (i.e. proper termination).

The D8B connection on the Lucid says it's properly terminated - no T-connector on the D8B and no other termination other than what's on the Apogee clock card... and that's always active.

While doing all of this, I noticed that there's one more orange (no proper termination) LED on the back of the Lucid, and that was for my PreSonus Quantum audio interface. I didn't know that's not internally terminated. Added a T-Connector and terminator on that end just now, and now that LED is green as well.

I've heard this before, but this confirms that not all audio devices with BNC clock connectors are internally terminated or switchable. Hopefully the R8 documentation says if it is... I don't recall reading anything about the Quantum not being internally terminated, so this can be a bit murky (but IMO, it's better to NOT internally terminate, since you can always add a terminator externally... but it's not as simple to remove termination if it's present but unwanted).
But maybe (just maybe) it might be necessary to add a t-connector piece and terminator on the R8-end as well, in case it doesn't terminate internally and/or isn't switchable for termination.

The Lucid Master Clock I'm using has 8 BNC Clock outs (and you can use them as 2 sets of 4 with different clock settings - but the multiplier has to be right - so, no mixing 44.1 and 48, but you could do 44.1 and 88.2, for example).

Basically, the way I have it hooked up is this:

Lucid BNC Out 1 -> PreSonus Quantum (now terminated via T+Terminator)
Lucid BNC Out 2 -> Universal Audio Apollo 8 (apparently internally terminated. LED green with straight connection)
Lucid BNC Out 3 -> D8B/Apogee Clock card (internally terminated. LED green with straight connection)
Lucid BNC Out 4 -> HDR (switch should be in, as I learned. Then the LED is green. Straight connection)
Lucid BNC Out 5 -> M-Audio Octane 8-channel ADAT pre (apparently internally terminated. LED green with straight connection). (The Octane, I'm not using for anything serious. It's just where the outs of my e-drum kit go for quick jamming... then from the ADAT out to the digital patchbay, so I can optionally route to the D8B - but I usually only use the e-kit to trigger plug-ins).

Additionally, I have a few of the devices above go into my digital patchbay (M-Audio DigiPatch 12x6), but that should be fine, since they're already clocked to each other. From there, I also loop in a Lexion MPX-200 (I know... but I got it cheap), so I can clock it off of the S/PDIF detour. (The Lucid would have extra S/PDIF connectors for clocking devices that don't have a BNC word-clock port, but I'm using the digital in/out on the Lexicon to avoid the cheap converters in that thing... so I need to run both, signal and clock via the S/PDIF on it).

There's some more stuff of the patchbay, like my old DAT machine (Panasonic SV-3700) that I also clock indirectly via the digital patchbay, on the very rare occasions that I turn that thing on. Same thing for the Alesis QSR synth I have... but I have to run EVERYTHING at 48 kHz when I use that since it can't do anything else... and I like to work in 44.1.

But over-all, I really like to have everything hooked up digitally, to avoid unnecessary conversions (I usually only use the digital inputs/outputs on the D8B as well... the Quantum and Apollo have 24 I/O going back and forth digitally to/fro the D8B, and I use the S/PDIF out to the Patchbay when I need to grab a mix from the D8B).

But yeah... a Master Clock makes things a lot easier. I never even think about the startup-order. No matter the order, they all just clock nicely to the Lucid.

I tried to avoid getting a master clock for some time and ran everything daisy-chained. But it's been too complex and I had to troubleshoot too frequently, so I eventually caved.
Traded an extra 12-channel analog snake I had lying around and only paid $100 on top for the Lucid. I see Aardvark clocks pop up on Craigslist here in LA for around $100 every now and then, so that would be a cheap way to add a master clock.

Personally, I do NOT really hear the supposedly SO MUCH wider/deeper stereo field that everyone claimed they heard when adding a Apogee Big Ben (didn't hear that on their system(s), either)... at least compared to how it sounded when I clocked everything off of the UAD Apollo. But IMO, the convenience is already worth it. If one of the devices acts up, there's no chasing down where on the daisy-chain it fails... it's just THAT connection.

Anyway... I guess I had a whole bunch of messed up settings for termination in my setup. Maybe I'll hear the wider stereo field now, after all, hahaha (doubt it).

[Y-my-R]

Those Aardvark Master Clocks I mentioned above can be had even cheaper now, it seems... here's on on the LA Craigslist for $50. (Although it says $180 OBO in the body of the ad... I hope that's just where the price dropped from).

https://losangeles.craigslist.org/lac/m ... 77735.html

Well worth the $50 "investment" IMO.

I'm not sure if the Aardvark can do this, but the Lucid I have also allows you to feed a Wordclock signal into it, and then feed that back out to the 8 BNC clock outputs it has (...but jitter-corrected, from what I understand).

So, if you're certain that the R8 has better clock than anything, you could use something like the Lucid GENx192 to "mult" it back out to the D8B and HDR (and a bunch of other stuff if you have more gear with BNC WC ins).

Again, though, not clear on what the Aardvark I'm linking to here can do. Just pointing out some options you'd have with "some" Master Clock units.

Just noticed that someone's selling the same Lucid Master Clock I have for $210 around my area:
https://losangeles.craigslist.org/sfv/m ... 67128.html

That was about as much as mine was listed at. The cheapest Apogee Big Ben I could find at the time was a bit under $500. At least to me, the theoretical improvement over the Lucid (that I still akin somewhat to snake-oil) was not worth double the price. Not much has changed, apparently. Here's a listing for a Big Ben for $475 in my area:

https://losangeles.craigslist.org/sfv/m ... 51816.html

If I remember right, the Big Ben can only do a single sample rate at once, though (the Lucid does 2 and keeps them in relative sync to each other). Besides, there's 2 fewer BNC outputs... not that I'd really need them. But it does have a WC input, that I would expect it can "mult" back out to the BNC outputs as well (...but didn't research this).

oh... and when I just looked for "Master Clock", I found a Lucid Gen6 for sale for $100 as well. These can only do 44.1/48, but they can also take WC in and distribute it back out to other devices. So, if you're mainly using 44.1/48 kHz devices, this would be an affordable way to get the R8 clock to each end-point without having to deal with daisy-chains and boot-up orders...

https://losangeles.craigslist.org/sfv/m ... 65990.html

Anyway... Master Clock makes sense, IMO. I'd recommend to add one.

[doktor1360]

Thanx for all the input Y-my-R...

On one of the prior responses, you pointed to the database page... specifically regarding the Apogee clock cards. You'd think as long as I've been hanging around here, that would have been the 1st thing I referenced. Everyone contributing to this thread is entitled to a free shin kick due to my cement-headed momentary lack of focus and subsequent bandwidth waste...

I'm eyeballing this item on eBay... I'm most likely gonna make an offer, but these things are certainly out there. I like the link to the Lucid GenX192 you posted, that's something I'd consider too if I could find it at a little lower price point. I'm fortunately at a point where I don't have a gun over my head, so I can spend some time and find something to do the deed, without a doubt...

https://www.ebay.com/itm/294565641105

All the input on this thread is pretty dope...

[nuss]

ironic I stopped in on this thread today!!

a Lucid clock just popped up on craigslist in Vancouver Canada for $250 cdn. that's probably what.....$10US?? haha!!!

no its not mine lol but would be worth it for you to look into!! I personally prefer the rosendahl clocks