Yes. Because the input impedance of the E27 is 13k ohms and the output impedance is less than 45 ohms, this means that the E27 could interface two unlikely pieces of gear.
For example, say you had a CD/MD/DAT player that has unbalanced outputs and you wanted it to drive an old compressor or equalizer you have. The problem here is that the output of the CD player cannot handle a heavy load of 600 ohms and when you do connect them, you will likely find that you lose low end and the high frequencies don’t sound very good. You can connect an E27 in between them, and even with the eq button not engaged you still go through the transformers and the 1122 opamp, which now has enough output current to drive 600 ohms easily.
Another example is, say you have a console or outboard gear that has electronically balanced outputs and you need to interface it with something that is unbalanced, and let’s say that it’s that old compressor or equalizer again. Some electronically balanced outputs can handle being unbalanced if it has been implemented in the design, but some cannot deal with being unbalanced in any way. Even unequal impedances to ground in a balanced system, like passive attenuators using potentiometers can cause problems. If you try pluggin the two together, what you will hear is a loss of level as well as a loss of low frequencies because what you are doing is driving one of the push-pull opamps into ground – and it does not like that. Put an E27 in between the two, and due to the transformers on the input and output, everything is happily working together.