Gab wrote:
From what I’ve read when I was looking to build a M77 clone, audio note purposely publish multiple schematics over the years. Probably for parts availability reasons, but they almost always miss some informations, or provide contradictory (if not misleading) informations when compared to other schematics. With all the know how of this company, (and all the respect I owe them) I don’t think that they make "mistakes" in their schematics. The difference between the real ones and the clones, besides parts and worksmanship quality, probably is what’s missing in the scematics.
Can we blame them for keeping little secrets ? I don’t think so

Just some more postings about a similar circuit (I have no connection its just for interest)
https://diyparadise.com/w/simple-5687-based-preamp/I had a look at the supposed original circuit and compared it with some equipment posted for sale on the internet
http://www.astrasuite.com/astrablog/uh- ... kondo-sfz/and the values seem to match.

(maybe)
But it is interesting to look at what others have done.
Its interesting to note that the magic wooden boards were not in use at that time, but then again its all just reflective for fun.
If these circuits have any reflection on the original is another possible maybe.
NB the wooden boards are described as "densified wood" but its an interesting thought.
Regards
M. Gregg