Years ago I bought the super-sweet Gately mixer system pictured above; it has long been sold-on (to a studio in TX IIRC) but wow really great kit. All UTC transformers, all discrete, modular, ETC.
You can learn more about Gately at these two earlier articles:
The system that I acquired and restored
Anyhow, reader M.Nathan has been so kind to scan some schematics of some of their later Series 8 kit. Nathan: “Here are three pics of the imp8 series 8 input module schematics. This section has the mic pre which, in isolation, is a pretty simple little thing.”
