A question about tape loops

I am in the market for a preamplifier. I have a DBX Expander in my system that connects to a tape loop. Do all preamps that have one or more tape loops allow you to use the tape loop and another source at the same time? I use the DBX for reel to reel tapes and phono. Thank you for your help.
I'm pretty sure that's the required functionality. With the tape loop engaged, I think the signal path would be:

selected source -> tape rec out -> tape rec in -> preamp out

That way you can monitor what was recorded.
There are preamps that DO NOT have tape loops,got to look,good luck,Bob