Balanced interconnection and ground

[antcollinet]

Pin 1 should not be the reference for a balanced input. If it is then you're doing it wrong. The signal is the difference between hot and cold,

That is correct. But that difference is normally detected with a Diff amp which itself is referenced to audio ground.

And

The interconnect should still work if the shield is disconnected at one end

Also correct - as long as the common mode voltage difference between the two devices (which may no longer be tied together) does not exceed the common mode voltage range of that diff amp.

 

[antcollinet]

That's why I assume the ground lift switch could help.

It might in your case where you have a balanced connection followed by unbalanced downstream.

With a fully balanced set up, it should be un-necessary.

(But also see @sam_adams post)

 

[RHO]

It might in your case where you have a balanced connection followed by unbalanced downstream.

With a fully balanced set up, it should be un-necessary.

(But also see @sam_adams post)

I agree.

The problem is that I cannot see how everything is connected inside the device. They all measure close to 0 Ohm. Maybe not surprising.
I will not open the devices since they are all still under warranty.

 

[antcollinet]

I agree.

The problem is that I cannot see how everything is connected inside the device. They all measure close to 0 Ohm. Maybe not surprising.
I will not open the devices since they are all still under warranty.

Of course. And it probably wouldn't be realistic to improve it even if it is "wrong". Plus no device using an unbalanced interconnect can achieve the noise immunity anyway. The only solution in that case is to prevent the (audio) ground currents - or other noise sources.

 

[RHO]

I'll build the balanced cables and we'll see what the results are.
Again, thanks for all the advice and explanations.