I just finshed the last wiring of my ST-70. I followed the instructions that covered first start up. I put the driver tubes in (I used 12AU7's because I didn't have any 12AT7's), and the tubes did not light up. I checked the AC voltage across the incoming heater wires and got 6.7 VAC. The B+ voltage to the board is 480VDC, "-50 VAC" voltage was -53.5, and pins 1 & 6 across all 3 tubes are 480VDC. I've attached pics so those kind enought to help can see my work. I used only the parts supplied with the board, and used the instructions found here to connect the VTA to the sds pwr supply board as well.
I'm stumped. Any and all thoughts, suggestions, etc. welcomed. I thought I would be listening to sweet, sweet music this Sunday evening, but no joy in Mudsville tonight. I'm certain this will get solved, but I need the wisdom of the great minds here.
Thanks for any and all help!
Chuck
I'm stumped. Any and all thoughts, suggestions, etc. welcomed. I thought I would be listening to sweet, sweet music this Sunday evening, but no joy in Mudsville tonight. I'm certain this will get solved, but I need the wisdom of the great minds here.
Thanks for any and all help!
Chuck