Later designs
This preamplifier was designed in 1982, and a prototype made in 1983. Only one unit exist, and it sounds wonderful. This is by far the best sounding preamplifier I ever have made. Still today I'm rather pleased with the design. It is divided into several Gain Blocks. In the schematics section accompanying this I've shown the block schematics and one of the gain stages, which is used two places. I will place more details on this design later.
This design was also made in one prototype, but it never made it into a fully working version, althught it worked partly. The design was rather good anyway, and had a lot of interesting features. The cooling fins, for example, used new heat transfer knowledge to its best. I have never seen similars either before or after.