maybe

I know that an SSM2142 balanced output driver chip without capacitors for DC blocking ... will fail.
BUT it will depend on the circuits involved.

A simple adaption lead with either DC blockers OR a 1:1 transformer interface box.
I prefer the 1:1 trafo ... perhasp with a level trim added.

If it helps I am referring to maybe a Mackie DFX-12 and perhaps a Soundcraft spirit 32chans.... Because Mackie DFX-12 is a "on-stage mixer". Is there any sites which can explain how phantom works and how mixer outs can be affected, i must be sure not to fry my board..

But if it depends on the circuit, erm, it depends on the stage mixer or the main mixer?

The source mixer needs to be safe for phantom from the destination mixer.
The source level needs to knocked down to usable levels for the mic input of the destination mixer.

See the Rane site amnd the Jensen site of interfacing ideas.
http://www.jensen-transformers.com/apps_sc.html

http://www.rane.com/library.html
http://www.rane.com/note110.html

I would use a transformer box for each channel
Each would have an earth lift and may have a trim adjust.

http://www.jensen-transformers.com/as/as081.pdf
http://www.jensen-transformers.com/as/as010.pdf
http://www.jensen-transformers.com/as/as036.pdf
http://www.jensen-transformers.com/as/as009.pdf

or even something like
http://www.jensen-transformers.com/as/as092.pdf

If I understand your problem correctly, you don't need to worry much with custom transformers. (Sorry Kev, I know you wanna draw schematics... :cry: )

You're trying to use one of the mixers as a submixer, right? Kind of a way of expanding the channels a bit? Well, the simple solution is to come out of the balanced XLR outputs into a cable that adapts from XLR to TRS and then come into the other board in TRS.

I'm assuming that your other board has global phantom and you're worried about killing the first mixer when it hits it?

Not a problem.

J.

Cucco wrote: (Sorry Kev, I know you wanna draw schematics... :cry: )

8)
yep

cucco is right
simple solution is always a good start and often is a final solution

one last plug for the transformers
If the mixers are far apart as would be with a stage mixer and a FOH mixer then the trafos can be very cool for ground loop and noise control

I'll shut up now