Thanks, guys! The external loop suggestion is an excellent idea - I wasn't sure it would work like this based on it's description in the manual, as I'd interpreted it as a signal processing (e.g., equalizing) path. Having to activate the external loop button reminds me of the old "tape monitor" button on cassette decks.

I, too, have been dismayed with the number of inputs on the 2150. This helps.

Does anyone have a suggestion whether the external loop ports would be more appropriate for the computer connection rather than the tape player conncetion? (I don't think it matter, really, as long as I pay attention to the external loop button.)