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Word Clock Termination?
Old 16th August 2005
Gear Head

Word Clock Termination?

I’m having trouble terminating the last piece of gear in my chain. My set up is AD16X used as master clock with termination switch set to off on rear panel (on AD16X), then running into Hammerfall 96/52 input, and into PSX100 for DA.

So the chain is as follows-
AD16X word clock Out.
running to wordclock In on the 96/52 with a T piece.
The other end of T piece running to wordclock In of PSX 100.
Computer and DA both slaved to AD16X masterclock.

So the PSX 100 being my DA, is the last piece in the chain that needs to be terminated. I’ve tried using a T piece on the wordclock input of the PSX and terminating the other end of the T, but I get ‘wordclock error’ on the PSX. If I put BNC cable straight into PSX, I get ‘lock’.

I’ve tested different T connectors and termination connectors incase of faults, but I still get the error message on the PSX.

I’ve called Apogee about my termination problem and they said the PSX may have internal termination, but they weren’t sure. ive also read thru the PSX manual & i cant find any mention of internal termination.

Does anyone know if the PSX has internal termination?????? AND…if it does, why am I still getting error messages when running with a terminator with T piece???? Is it bcos you cant ‘double terminate’ if the PSX is already terminated??

any info much appreciated!
Old 16th August 2005
Lives for gear
gainreduction's Avatar

If it works without termination, is it a problem then..? Maybe the termination switch on the DA-16 should be set to off because you terminate in the recieving end, never in both ends. But then again I don't know if the termination switch affects the clock at all since you only use the WC output on the Da-16.

In your case I'm not sure if the word-clock will improve the sound of the system since all units are of high quality with good internal clocks and I suppose it's all adat-lightpipe connections since its a 9652-card. The best results may come from letting the internal crystals clean up the clock recieved within the optical cable. At least the AD will probably sound the best with its internal clock and then you might wanna clock the 9652 to the PSX, that probably gives you the least jitter where it really matters, going to digital. Then use the internal clock of the DA-16 to clean up the incoming adat-signal.

I really think Dan Lavry's theory of always having the AD internally clocked makes a lot of sense because cables no matter how good always add some amount of jitter. The clock inside the AD is inside the box and the cable run from clock to converter can't get shorter than that. In other words, least amount of jitter added.

And the PSX has a good internal clock.
Old 16th August 2005
Lives for gear
gainreduction's Avatar

Oh, don't mind the first line, I see now that you have the termination switch set to off on the DA-16. Sorry.

And I mixed up your AD and DA... thought it was the other way around... that you used the psx for AD... sorry again. Need coffee ... tutt

Maybe the PSX is auto-terminated, that's my guess.
Old 16th August 2005
Gear Nut
Moofie's Avatar

My PSX behaves fine without a terminator when "seeing" wordclock. I'd relax, have glass of red wine and move on.


Old 17th August 2005
Gear Head

just bumping this up : )
Old 17th August 2005
Gear Head

thanks gainreduction : )


i understand that your PSX works fine, so does mine. but my concern is the 'backwash' (not exactly the correct technical term but im sure you'll know what im getting at!) effect that is created if the last piece of the chain isnt terminated. square waves crashing into one another on their 'return trip' that havent been terminated. which can then result in under OR over termination issues and slightly degrades your sound -admittedly IF audible??!?
Old 17th August 2005
Gear Head

....maybe simpler to just ask- Anyone know if the PSX is already terminated??
Old 17th August 2005
Gear Guru
rickrock305's Avatar

i don't know if its internally terminated, sorry. But i thought I'd say i run stuff with and without terminators all the time without much of a problem. If there is a difference in sound because of it, its got to be minimal...and thats a little too technical and not enough musical for me personally.

edit...although i have wondered about it so if anyone would like to clear me up on it, feel free.
Old 17th August 2005
Lives for gear
doug_hti's Avatar

The psx is probably (almost definately) automatically terminated.
A lot of the newer digital devices are....even though the psx has some age to it.
But it IS not uncommon for things to be interally terminated.

If there is actually a clock error, then just run it internally terminated.
However, some of the clock sensing sensors (such as Big Ben's) will not always show that things are complete lock, when they should be(and are).

And IME, if it's showing it's locked, it's locked.
Old 18th August 2005
Gear Head

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