This build is a clone of the Trident A-Range console strip. It is a mic preamp or line amp followed by a 6 channel EQ: 4 mid bands and high and low shelves.
Based on examining the channel strips and original schematics at Smart Studios in Madison, WI, I drew a PCB, closely following the original routing. Like the original, two transformers are used for the mic and line input, with the 3 deck grayhill switch selecting the gain and input.
The inductors were wound by ChrioN at groupdiy from specs calculated from the schematic. An initial attempt was built up and I brought it over to the Studio. Listening side-by-side against the vintage Trident console, the Inductor bands did not sound right. Re-examing the original channels, the originals had different inductor cores (N30). A new set of inductors were wound and prototyped and the sound performance of the clone was very close to the original Trident.
Vintage St. Ives 1:1 output transformers were used to produce a balanced output. The vintage channels have an unbalanced output.