zero on the mixpre may or may not be "ideal", but its a fair bit of testing to determine the optimum level for S/N, and diminishing return at that.
the "tape out" of an FP24 is an easy mini-to-mini-connection to the mixpre aux in and runs at +11dBFS
Thanks! Just called around and have a MixPre-D on the way. I didn't realize the MixpPre-D and FP24 have 3.5mm tape output. I've actually never used a tape output before before---is there any disadvantage to using it vs. the XLR outs? (Cringing again at the thought of my recordings depending on not one, but two 3.5mm jacks...)
I had planned to either:
-Buy/make a two-XLR-F to 3.5mm TRS stereo breakout cable to go from the MixPre-D's two XLR's outputs to the MixPre-6 3.5mm TRS input.
Or
-buy/make an TA3F (mini XLR) to 3.5mm TRS cable to go from the Mixpre-D's mini XLR unbalanced output.
Thank you all for all of the help!