Minor comment, and not exactly related to your questions, but I've found when tracking on my 38 that it's usually not a good idea to record through any sort of patchbay or mixer but rather just directly from your mic preamp or whatever to the tape deck. Remember that everything matters in terms of noise and sound quality- cables, preamps, etc. So if you go direct in from a mic preamp, your signal chain consists of:
Microphone-->mic cable--->mic pre-->cable-->tape deck input
whereas just using one patchbay/mixer will bump it up to:
Microphone-->mic cable-->mic pre-->cable-->patchbay/mixer-->cable--->tape deck input.
This is a good way to double the noise added to your signal, and also unless you manage to get an incredibly transparent patchbay/mixer its output can sound significantly worse than the direct out from your preamp.
Cheers,
theo