Tape in + tape monitor = passive preamp?

If you plug a line-level source into a preamp's "tape in" jacks, then flip the "tape monitor" switch, do you essentially get a passive preamp?

I ran across a post on the AudioCircle Bryston forum claiming that the "best input" on a Bryston BP26 was the tape in (or, as Bryston calls it, "tape from"). Here's the url, and the claim appears in the two entries by "werd": http://www.audiocircle.com/index.php?topic=69427.0

I checked the schematic for my B60R on the Bryston website to see if the same would apply to its preamp section. Sure enough, it does (if I read the diagram correctly). From the "tape from" input, the signal goes almost directly to the balance and volume controls; while the signal from any of the four main inputs goes through the selector switch and a multi-step circuit (pre-amplification, I assume) before reaching the balance and volume controls.

I decided to hear for myself how using the "tape from" input would affect the sound of my system. My initial impressions are that the sound is more detailed, primarily in the upper frequencies, but that it lacks body and bass. Switching back to the CD input results in a loss of HF detail but a more balanced sound.

I'm going to try living with the system in the "tape from" set up for a while. I like the extra detail, and maybe I'll get used to the frequency balance.

Has anyone else experimented with this technique? Using other brands of gear? Any advice on reclaiming the bass?