ground loop over wordclock

Hi.

I seem to have groundloop over BNC wordclock, 44kHz. How to deal with it?

Is there a way to isolate it? Maybe simple DIY ferrite ring transformer? Maybe I can use transformer from switching PC power supply? Or transformer from old PC network card?

Any suggestions?

thnx

Wordclock and something else I assume... (it usually takes at least TWO paths to make a loop)

Can you lift the OTHER ground?

Keith

try keiths suggestion first.

if all else fails, a video isolation transformer should work
theyre expensive new but look on ebay for a used one

[quote author="SSLtech"]Wordclock and something else I assume... (it usually takes at least TWO paths to make a loop)

Can you lift the OTHER ground?

Keith[/quote]

Yes, connection is between PC adat card (Hammerfall HDSP) and ADA8000 converter. One part of loop is mains connection, the other is through wordclock.

No ground lift on converter or PC.

I'll check video iso, but... I'm looking for a cheap solution, clearly. How about a simple DIY ferrite ring transformer? Would that be hard to do?

...

How about this?

http://www.epanorama.net/documents/audio/spdif.html
(look down arround middle of article)

It is for SPDIF, but that should work for wordclock, is it?, because spdif has even higher bandwidth than 44kHz wordclock.

They suggest:

The transformer T1 is high quality 1:1 pulse transformer (can be salvaged from old broken network interface card or similar source).

Click to expand...

or

The transformer T1 is made to G2.3-FT12 ferrite ring core. Primary coil is 15 turns of 0.5 mm diameter enamelled copper wire and secondary is 3 turns of 0.5 mm diameter enamelled copper wire.

Click to expand...

What do you think about this?
Old network card? Or DIY ferrite ring core?

BTW, what does it mean "G2.3-FT12 ferrite ring core"? Is it a size? Could I take one out of old PC switching power supply?

...

jensen app note from 1964

Funny, I bet, Behringer has left out the important transformer, which is needed in S/PDIF specification

[quote author="TobWen"]Funny, I bet, Behringer has left out the important transformer, which is needed in S/PDIF specification [/quote]

Well, even if Behr let out that transformer (not SPDIF, but WC), if RME Hammerfall would have one, ground loop would be broken. I guess neither of them has isolated WC teminal, thats why I have to scratch my head now....

As far as I know Word clock is very tolerant against ground noise. Is that a real problem? Adding transformers can be more problematic than the current situation.

[quote author="audiox"]As far as I know Word clock is very tolerant against ground noise. Is that a real problem? Adding transformers can be more problematic than the current situation.[/quote]

Well, it is not that I hear buzz or anything. But even when I turn off ADA8000, all LED's remain lighting very dimly (can be seen only in total dark). If I unplug either wordclock BNC or power cord, LEDS go entirely off. Based on this I'm concluding, that I have some ground loop, or some voltage between ground and WC, that causes LEDS to light dimly.

And if there is some voltage running arround through WC, then I wonder what it does to wc/sync, because it surely modulates WC, and that may not be good, it surely increases jitter, I guess.... What do you think?

I can try rewiring power of ADA8000, to bring it closer to computer with RME card. Will experiment a bit.

...