All seem to be labeled with Marantz part numbers, rather than actual transistor designations. Has anyone out there decoded these and ID'd one or more substitutions?
OK. Well, I've kinda figured out that there are likely many possible transistor substitutes based on the requirements of the circuit design and operating parameters.
Transistor substitutions may be hard to come by. I believe that the 7T used germainium transistors. They have a much lower Vbe than silicon, which would require a complete rework of the circuit values. Someone please correct me if I am wrong.