Returning to the discussion of the heritage of the First Sound preamp, I did a little digging. It seems that Mr. Go of First Sound commissioned P.Wietzel for a schematic of a tube preamp circuit. It was a very basic, class A triode with a tube regulator on the B+.
Mr. Go, with the collaboration of several other engineers (P. Weitzel not among them), designed the First Sound preamp in 1991. The first unit was sold in the fall of 1991. Since then, there has been a lot of work done to raise the performance of the First Sound preamps to their current level. This includes parts selection, chassis design and construction, circuit implementation, wiring choices, and the way all of these elements come together and are voiced to create the final product. In my book, Emmanuel Go gets full credit (and responsibility) for this preamp.