After the initial circuit design of the BHK 250, the ever talented Bob Stadtherr designed the first circuit board and heatsink for me to debug and make work. Having this on my lab bench for while convinced me that I had made a pretty big mistake on the output stage and had to change it. See 1.jpg. As can be seen, considerable additional components and rewiring had to be done to make it work the way I wanted. 2.jpg is a closer look at the situation. After this, I got the second heat sink going. Next the tube input stage and associated circuitry was made to work as a separate AC operated unit. This is shown in 3.jpg. Now I am starting to assemble the amp as shown in 4.jpg. Further assembly to getting ready to listen and in 5.jpg and 6.jpg. In to my listening room and OMG, what have I wrought, it sounds great!
As a matter of interest, I had loaned this amp to a good friend for the past year or two. He recently passed away and I and others have taken on the task of selling off his extensive sound system. I have put this amp up for sale in that effort and if anyone might want to have it as a working historical item, let me know.