Cary SLP-98 tape out question

I sometimes run the Cary preamp into an integrated amp by using its tape out connectors.  I've found out the Cary unit doesn't need to be turned on in this mode in order for the signal to reach the integrated amp.

I've used the tape out function on various preamps and never realized the pre didn't need to be turned on to use it that way.

Is this normal for all preamps with the tape out function or something unique to the Cary?
Thanks, and stay safe.