I haven’t scrutinized everything, but don’t believe schematic can be correct re connection of Q105 base to feedback divider.
the schematics is incomplete, the bias generator is missing, it should be connected to those points labeled with letters, probably other parts are also missed
My point was that Q105 has to be wrong. The base likely is not connected at the diodes, but rather probably connects at the junction of R116, R117.
you are right, there are many things wrong in the sch., initially in a quick look I thought the diodes were connected between the input bases (common practice to avoid deep saturation) but then I saw they are in parallel with a 3V electrolytic, so probably over cap voltage protection.
Anyway, this sch. is taken from a magazine, I do not think it is worth to spend a lot of time on it
Anyway, this sch. is taken from a magazine, I do not think it is worth to spend a lot of time on it
as post 3 points out, there is one REALLY big mistake that is so obvious it's funny. but yes, the magazine review did state that some functional elements were missing. reviewers are not always given the complete product schematics, especially if it is known they could be published, as Audio magazine often did during its existence. there is enough info to help a knowledgeable person get some overall understanding of the product design and operation or possibly help with troubleshooting. if more info is desired, read the review in Audio magazine (starts on page 96) or read through the product spec info at the website.