I’m not able to follow completely, but I know you can run one preamp into another because that’s exactly what I do for my stereo.
I have a McIntosh MX110z, which has a limited number of inputs, so I have a Kenwood Basic C2 preamp (which is where I have the TV, CD player, and a couple of other things plugged in), and I use the "Tape Out" output on the Kenwood and connect it to the the "Auxiliary" input on the McIntosh.
The key is having a "Tape Out" output for an unamplified output from the first preamp, but maybe you don’t have that (and maybe I’m completely off the mark since you are talking about music creation instead of reproduction).
Anyway, good luck.
I have a McIntosh MX110z, which has a limited number of inputs, so I have a Kenwood Basic C2 preamp (which is where I have the TV, CD player, and a couple of other things plugged in), and I use the "Tape Out" output on the Kenwood and connect it to the the "Auxiliary" input on the McIntosh.
The key is having a "Tape Out" output for an unamplified output from the first preamp, but maybe you don’t have that (and maybe I’m completely off the mark since you are talking about music creation instead of reproduction).
Anyway, good luck.