Decklink Duo

[ajmaudio]

Power issues would point to faulty earth or large voltages on earths remember sdi needs a ground
And if it's not common between video and lighting you blow things up.

Thing you need to investigate ground potentials and ground spikes in your sdi cables

It's more than possible this is source of problem

We use different phases for systems on most shows and video and lighting and sound equipment cannot be connected together through direct signal cables

You need isolated equipment

This is very true.. if your cards arent being physically damaged from handling etc I would put money on this. You can even get smoked from bad building service.. had a show this year that had about a 6v difference in GROUND potential between 2 lighting services that where supposedly on same xformer, panel.. etc etc... got a nice buzz plugging in a soco just touching the chassis...but when just metering that service itself it was fine... there seems to be no end to bizzar bad bad things that can pop up in the world of show power.

[samsc]

This is very true.. if your cards arent being physically damaged from handling etc I would put money on this. You can even get smoked from bad building service.. had a show this year that had about a 6v difference in GROUND potential between 2 lighting services that where supposedly on same xformer, panel.. etc etc... got a nice buzz plugging in a soco just touching the chassis...but when just metering that service itself it was fine... there seems to be no end to bizzar bad bad things that can pop up in the world of show power.

the sdi signal is relatively insensitive to low frequency ac/dc noise - as its self clocked and is a transition based signal- so low frequency dc/ac offsets are easy to filter out with a high pass filter- - up to a point...