Audio issues coming from sound board to ATEM system

Hey guys. I need some insight as to an issue I have run into with our streaming equipment. I am using an ATEM 2 M/E Production 4K. I have run an audio cable from our older sound board to the ATEM hardware via a Matrix output on the soundboard. I had to add an in-line pre-amp due to extremely low levels. I have run into an issue where there is a constant ticking noise. It is not coming from the pre-amp because it was there before. The pre-amp has just enhanced it along with everything I wanted enhanced. As mentioned before it is an older board and that may have something to do with it. If anyone has any pointers I would greatly appreciate any advise at all. Thank you.

The use of an isolation transformer is SOP when doing this kind of thing. I typically use one of these to isolate FOH from Videotown for our record and monitoring feeds.

http://www.sescom.com/product.asp?item=IL-19-2S

This one seems fancier with some ground lift switches but the ground is isolated by the transformer so I'm not sure exactly what you're paying for, maybe the ground is causing noise upstream of the transformer and this helps prevent it.

http://www.sescom.com/product.asp?item=SES-XLR-ISO-02

And, any sound mixer with a Matrix ought to be outputting a true +4 balanced line level, probably on 1/4” TRS. Perhaps there’s something wrong with the Matrix mixing hardware, or an error in the signal routing?

Have you tried other outputs of the mixer to narrow in a bit?

Seth sorry for the delayed response on this issue. We have just kind of chalked it up to the soundboard being the issue. It doesn't matter what output we use from the soundboard to the ATEM hardware we still get a popping/ticking noise. If you are completely board I could try to find a broadcast test that includes the tapping noise to see if you have any ideas as to what type of gremlins we are dealing with.

Geoffrey