Yes challenging, but i still hope to come up with something. After all, i don't need that much amplification to match the ensemble. It gives me a feeling that its feasible, so far.
...The more i search, the more i find! I have been reading other posts, links and related searches already mentioned here. it really takes time to get a hold of my options and limits for this project, but i'll try to make a point of situation right now. I'll repeat myself and other user's posts in some points...
Here are some interesting links i found regarding this kind of device(this is more for me or anyone wanting to gather info):
the user Teleman made something beyond my needs, but ideal, in this discussion(end of page 1)
http://www.diyaudio.com/forums/analog-line-level/205980-help-circuit-preamp-eq-balanced-output-powered-phantom-power.html
about balanced signals
http://groupdiy.com/index.php?topic=11723.msg136998#msg136998
Calrec type of Eq is far out of reach for me. The linkwitz lab has more than enough info to source filters and other corrections to the signal, i think
http://www.linkwitzlab.com/filters.htm#11
Another high end product of the same type
http://www.appliedmicrophone.com/portfolio/amt-s15g/
- Pzm mics would be nice to work with, despite all the possible problems they would have in this situation; specially the application on the surface of the soundhole, wich is moving as it amplifies strings, therefore making its technology impredictable in this case(right?)... I would buy some of these ( not the 100's$ ones, neither the big enclosure ones) just to try them out, if you know where to get them please point me there(i've been searching, couldn't find any so far- im based in Europe).
So, for now i have unidirectional and "noise rejection" electret capsules to start with. Bruce0 mentioned his Nebish circuit, posted here http://groupdiy.com/index.php?topic=43085.msg546752#msg546752
I found this (i think) somewhat similar circuit http://www.mp3forkidz.com/mic/phantxy.html . It seems easier than bruce0, specially because i don't have etching tools.... I'm going to build as soon as i get all the parts. i'll do the linkwitz mod to both WM34 and WM55 - Then i'll try to shootout the best position to fix the capsule on the instrument.
As an example, i recorded these tracks (first 5 tracks) https://soundcloud.com/paulorosa-2 with an Rode NT1000 and MXL V69, into a That mic Pre http://electronics.dantimax.dk/Kits/Preamps_-_poweramps/index.html, into a Emu 1212m. This kind of maccaferri guitars have a "rude" type of sound to it....