Woodo wrote:
Hi and welcome. An interesting project. Love the cabinet and looks like a sturdy chassis. My 6sn7s filaments were powered by 6.3vAC too and if I recall correctly there was a centre tap from the edcor power transformer I connected to the ground bus. I’ll check that.
Thanks from "Down Under".... The chassis is anything but flimsy, and the power tx'former is a serious lump of iron. I've just finished the physical layout of the components (on paper). I'd forgotten what a job it is to translate a tube schematic into an 'orderly' physical layout. It's been over 40 years.
To mount the components I'm cutting small boards, for grouping components by stage. I'm using pieces of hardboard that came from the original large perforated board, that was the back of the cabinet, How and where to mount the boards on the chassis, is another question.
The power transformer checks out, filament voltages are nicely balanced, I plugged in the original preamp 7025A tubes, to check filaments, and the tube warms up nicely. Voltages check out. Difficult to see a glow,, because the tube is in the orignal metal shield (which appears now, to be a permanent fixture after all this time).. Power transformer has center tap for secondary, but not on the filament windings. I am debating whether or not to rewire the filaments, but at the moment, it seems to be fully functional.
Hope to begin soldering very soon. I'll post a photo, when the project is nearing completion.
BTW, I was born and brought up in South Wales, and I remember the song from the 60's, when Welsh rugby was at an all time high,
" Who beat the wallabies, but good old sospan fach !!"
Rgds