845 Project

[pre65]

Hi-using bits left from the now dismantled PT15 monoblocks i have started my new project,an 845 power stage.

This is to be driven from my existing 300b single ended amp with an 2-1 interstage transformer replacing the output transformer.

This is my first attempt at anything HIGH voltage and also using the breadboard technique.The hardware is now mounted on the ply bases (thanks DTB) and now i can start to work out where all the wires should go.

The 845 heater is DC and i have just managed to get 10V from a 9V toroid and 1N5820 diodes + cap.

The power supply is 360-0-360 transformer via a hybrid bridge rectifier (high voltage silicon diodes and 6D22s damper diodes with raised heater voltage).Because of the high voltage i have made the power supply circuit board from 2mm teflon sheet and used turret tags for the connections.

Thanks to Nick G,Darren and Andrew I for the help in getting the details of the circuit sorted and making me so aware of the dangers of circuits with high voltages (900-1000V) .So many components that are "happy" up to 600v are just not safe at 1000V !!!

My choke for example is rated at 1.5KV,which was fortunate and the power supply caps are in sets of 3,each rated at 400V.

http://i111.photobucket.com/albums/n...readboards.jpg



Philip